SSM框架如何调用多个数据库

SSM框架在数据读取时，如何连接多个数据库，如何配置，如何指定是哪一个数据库？ 求大神解答

ssm框架，无法访问数据库Could not get JDBC Connection

用的德鲁伊连接池，先看applicationContext-dao.xml里的配置 ``` <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:context="http://www.springframework.org/schema/context" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd "> <context:property-placeholder location="classpath:properties/*.properties" /> <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource" destroy-method="close"> <property name="url" value="${jdbc.url}" /> <property name="username" value="${jdbc.username}" /> <property name="password" value="${jdbc.password}" /> <property name="driverClassName" value="${jdbc.driver}" /> <property name="maxActive" value="10" /> <property name="minIdle" value="5" /> <!-- <property name="maxWait" value="5000" /> --> </bean> <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <property name="dataSource" ref="dataSource" /> <property name="configLocation" value="classpath:mybatis/SqlMapConfig.xml" /> </bean> <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <property name="basePackage" value="com.demo.mapper" /> </bean> </beans> ``` 这样的话，控制台输出： 2017-12-28 12:43:58,209DEBUG[org.springframework.web.servlet.DispatcherServlet] - <DispatcherServlet with name 'case' processing GET request for [/case/test]> 2017-12-28 12:43:58,214DEBUG[org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping] - <Looking up handler method for path /test> 2017-12-28 12:43:58,221DEBUG[org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping] - <Returning handler method [public com.demo.pojo.TbItem com.demo.controller.TestController.getItem(java.lang.Long)]> 2017-12-28 12:43:58,221DEBUG[org.springframework.beans.factory.support.DefaultListableBeanFactory] - <Returning cached instance of singleton bean 'testController'> 2017-12-28 12:43:58,222DEBUG[org.springframework.web.servlet.DispatcherServlet] - <Last-Modified value for [/case/test] is: -1> 2017-12-28 12:43:58,317DEBUG[org.mybatis.spring.SqlSessionUtils] - <Creating a new SqlSession> 2017-12-28 12:43:58,335DEBUG[org.mybatis.spring.SqlSessionUtils] - <Registering transaction synchronization for SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@727efb8d]> 2017-12-28 12:43:58,366DEBUG[org.springframework.jdbc.datasource.DataSourceUtils] - <Fetching JDBC Connection from DataSource> 2017-12-28 12:43:58,447INFO[com.alibaba.druid.pool.DruidDataSource] - <{dataSource-1} inited> 一直显示等待，后来加了个maxWait属性，时间是5秒，然后才开始报错，如下： 2017-12-28 12:47:41,261DEBUG[org.springframework.web.servlet.DispatcherServlet] - <DispatcherServlet with name 'case' processing GET request for [/case/test]> 2017-12-28 12:47:41,264DEBUG[org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping] - <Looking up handler method for path /test> 2017-12-28 12:47:41,269DEBUG[org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping] - <Returning handler method [public com.demo.pojo.TbItem com.demo.controller.TestController.getItem(java.lang.Long)]> 2017-12-28 12:47:41,269DEBUG[org.springframework.beans.factory.support.DefaultListableBeanFactory] - <Returning cached instance of singleton bean 'testController'> 2017-12-28 12:47:41,270DEBUG[org.springframework.web.servlet.DispatcherServlet] - <Last-Modified value for [/case/test] is: -1> 2017-12-28 12:47:41,338DEBUG[org.mybatis.spring.SqlSessionUtils] - <Creating a new SqlSession> 2017-12-28 12:47:41,348DEBUG[org.mybatis.spring.SqlSessionUtils] - <Registering transaction synchronization for SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@3a67d807]> 2017-12-28 12:47:41,378DEBUG[org.springframework.jdbc.datasource.DataSourceUtils] - <Fetching JDBC Connection from DataSource> 2017-12-28 12:47:41,472INFO[com.alibaba.druid.pool.DruidDataSource] - <{dataSource-1} inited> 2017-12-28 12:47:46,473WARN[com.alibaba.druid.pool.DruidDataSource] - <not full timeout retry : 1> 2017-12-28 12:47:51,476DEBUG[org.mybatis.spring.SqlSessionUtils] - <Releasing transactional SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@3a67d807]> 2017-12-28 12:47:51,476DEBUG[org.mybatis.spring.SqlSessionUtils] - <Transaction synchronization deregistering SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@3a67d807]> 2017-12-28 12:47:51,476DEBUG[org.mybatis.spring.SqlSessionUtils] - <Transaction synchronization closing SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@3a67d807]> 2017-12-28 12:47:51,476DEBUG[org.springframework.jdbc.datasource.DataSourceTransactionManager] - <Should roll back transaction but cannot - no transaction available> 2017-12-28 12:47:51,478DEBUG[org.springframework.web.servlet.mvc.method.annotation.ExceptionHandlerExceptionResolver] - <Resolving exception from handler [public com.demo.pojo.TbItem com.demo.controller.TestController.getItem(java.lang.Long)]: org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.exceptions.PersistenceException: ### Error querying database. Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; nested exception is com.alibaba.druid.pool.GetConnectionTimeoutException: wait millis 5000, active 0 ### The error may exist in com/demo/mapper/TbItemMapper.xml ### The error may involve com.demo.mapper.TbItemMapper.selectByPrimaryKey ### The error occurred while executing a query 无法连接到数据库。。。。错误显示可能在/TbItemMapper.xml，这是mybatis逆向生成的，在其他项目中测试可用，所以问题应该不在这，其他配置文件啥的也感觉没问题，但就是连接不到数据库，问题出在哪？？？ TbItemMapper.xml： ``` <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd"> <mapper namespace="com.demo.mapper.TbItemMapper"> <resultMap id="BaseResultMap" type="com.demo.pojo.TbItem"> <id column="id" jdbcType="BIGINT" property="id" /> <result column="title" jdbcType="VARCHAR" property="title" /> <result column="sell_point" jdbcType="VARCHAR" property="sellPoint" /> <result column="price" jdbcType="BIGINT" property="price" /> <result column="num" jdbcType="INTEGER" property="num" /> <result column="barcode" jdbcType="VARCHAR" property="barcode" /> <result column="image" jdbcType="VARCHAR" property="image" /> <result column="cid" jdbcType="BIGINT" property="cid" /> <result column="status" jdbcType="TINYINT" property="status" /> <result column="created" jdbcType="TIMESTAMP" property="created" /> <result column="updated" jdbcType="TIMESTAMP" property="updated" /> </resultMap> <sql id="Example_Where_Clause"> <where> <foreach collection="oredCriteria" item="criteria" separator="or"> <if test="criteria.valid"> <trim prefix="(" prefixOverrides="and" suffix=")"> <foreach collection="criteria.criteria" item="criterion"> <choose> <when test="criterion.noValue"> and ${criterion.condition} </when> <when test="criterion.singleValue"> and ${criterion.condition} #{criterion.value} </when> <when test="criterion.betweenValue"> and ${criterion.condition} #{criterion.value} and #{criterion.secondValue} </when> <when test="criterion.listValue"> and ${criterion.condition} <foreach close=")" collection="criterion.value" item="listItem" open="(" separator=","> #{listItem} </foreach> </when> </choose> </foreach> </trim> </if> </foreach> </where> </sql> <sql id="Update_By_Example_Where_Clause"> <where> <foreach collection="example.oredCriteria" item="criteria" separator="or"> <if test="criteria.valid"> <trim prefix="(" prefixOverrides="and" suffix=")"> <foreach collection="criteria.criteria" item="criterion"> <choose> <when test="criterion.noValue"> and ${criterion.condition} </when> <when test="criterion.singleValue"> and ${criterion.condition} #{criterion.value} </when> <when test="criterion.betweenValue"> and ${criterion.condition} #{criterion.value} and #{criterion.secondValue} </when> <when test="criterion.listValue"> and ${criterion.condition} <foreach close=")" collection="criterion.value" item="listItem" open="(" separator=","> #{listItem} </foreach> </when> </choose> </foreach> </trim> </if> </foreach> </where> </sql> <sql id="Base_Column_List"> id, title, sell_point, price, num, barcode, image, cid, status, created, updated </sql> <select id="selectByExample" parameterType="com.demo.pojo.TbItemExample" resultMap="BaseResultMap"> select <if test="distinct"> distinct </if> <include refid="Base_Column_List" /> from tb_item <if test="_parameter != null"> <include refid="Example_Where_Clause" /> </if> <if test="orderByClause != null"> order by ${orderByClause} </if> </select> <select id="selectByPrimaryKey" parameterType="java.lang.Long" resultMap="BaseResultMap"> select <include refid="Base_Column_List" /> from tb_item where id = #{id,jdbcType=BIGINT} </select> <delete id="deleteByPrimaryKey" parameterType="java.lang.Long"> delete from tb_item where id = #{id,jdbcType=BIGINT} </delete> <delete id="deleteByExample" parameterType="com.demo.pojo.TbItemExample"> delete from tb_item <if test="_parameter != null"> <include refid="Example_Where_Clause" /> </if> </delete> <insert id="insert" parameterType="com.demo.pojo.TbItem"> insert into tb_item (id, title, sell_point, price, num, barcode, image, cid, status, created, updated) values (#{id,jdbcType=BIGINT}, #{title,jdbcType=VARCHAR}, #{sellPoint,jdbcType=VARCHAR}, #{price,jdbcType=BIGINT}, #{num,jdbcType=INTEGER}, #{barcode,jdbcType=VARCHAR}, #{image,jdbcType=VARCHAR}, #{cid,jdbcType=BIGINT}, #{status,jdbcType=TINYINT}, #{created,jdbcType=TIMESTAMP}, #{updated,jdbcType=TIMESTAMP}) </insert> <insert id="insertSelective" parameterType="com.demo.pojo.TbItem"> insert into tb_item <trim prefix="(" suffix=")" suffixOverrides=","> <if test="id != null"> id, </if> <if test="title != null"> title, </if> <if test="sellPoint != null"> sell_point, </if> <if test="price != null"> price, </if> <if test="num != null"> num, </if> <if test="barcode != null"> barcode, </if> <if test="image != null"> image, </if> <if test="cid != null"> cid, </if> <if test="status != null"> status, </if> <if test="created != null"> created, </if> <if test="updated != null"> updated, </if> </trim> <trim prefix="values (" suffix=")" suffixOverrides=","> <if test="id != null"> #{id,jdbcType=BIGINT}, </if> <if test="title != null"> #{title,jdbcType=VARCHAR}, </if> <if test="sellPoint != null"> #{sellPoint,jdbcType=VARCHAR}, </if> <if test="price != null"> #{price,jdbcType=BIGINT}, </if> <if test="num != null"> #{num,jdbcType=INTEGER}, </if> <if test="barcode != null"> #{barcode,jdbcType=VARCHAR}, </if> <if test="image != null"> #{image,jdbcType=VARCHAR}, </if> <if test="cid != null"> #{cid,jdbcType=BIGINT}, </if> <if test="status != null"> #{status,jdbcType=TINYINT}, </if> <if test="created != null"> #{created,jdbcType=TIMESTAMP}, </if> <if test="updated != null"> #{updated,jdbcType=TIMESTAMP}, </if> </trim> </insert> <select id="countByExample" parameterType="com.demo.pojo.TbItemExample" resultType="java.lang.Long"> select count(*) from tb_item <if test="_parameter != null"> <include refid="Example_Where_Clause" /> </if> </select> <update id="updateByExampleSelective" parameterType="map"> update tb_item <set> <if test="record.id != null"> id = #{record.id,jdbcType=BIGINT}, </if> <if test="record.title != null"> title = #{record.title,jdbcType=VARCHAR}, </if> <if test="record.sellPoint != null"> sell_point = #{record.sellPoint,jdbcType=VARCHAR}, </if> <if test="record.price != null"> price = #{record.price,jdbcType=BIGINT}, </if> <if test="record.num != null"> num = #{record.num,jdbcType=INTEGER}, </if> <if test="record.barcode != null"> barcode = #{record.barcode,jdbcType=VARCHAR}, </if> <if test="record.image != null"> image = #{record.image,jdbcType=VARCHAR}, </if> <if test="record.cid != null"> cid = #{record.cid,jdbcType=BIGINT}, </if> <if test="record.status != null"> status = #{record.status,jdbcType=TINYINT}, </if> <if test="record.created != null"> created = #{record.created,jdbcType=TIMESTAMP}, </if> <if test="record.updated != null"> updated = #{record.updated,jdbcType=TIMESTAMP}, </if> </set> <if test="_parameter != null"> <include refid="Update_By_Example_Where_Clause" /> </if> </update> <update id="updateByExample" parameterType="map"> update tb_item set id = #{record.id,jdbcType=BIGINT}, title = #{record.title,jdbcType=VARCHAR}, sell_point = #{record.sellPoint,jdbcType=VARCHAR}, price = #{record.price,jdbcType=BIGINT}, num = #{record.num,jdbcType=INTEGER}, barcode = #{record.barcode,jdbcType=VARCHAR}, image = #{record.image,jdbcType=VARCHAR}, cid = #{record.cid,jdbcType=BIGINT}, status = #{record.status,jdbcType=TINYINT}, created = #{record.created,jdbcType=TIMESTAMP}, updated = #{record.updated,jdbcType=TIMESTAMP} <if test="_parameter != null"> <include refid="Update_By_Example_Where_Clause" /> </if> </update> <update id="updateByPrimaryKeySelective" parameterType="com.demo.pojo.TbItem"> update tb_item <set> <if test="title != null"> title = #{title,jdbcType=VARCHAR}, </if> <if test="sellPoint != null"> sell_point = #{sellPoint,jdbcType=VARCHAR}, </if> <if test="price != null"> price = #{price,jdbcType=BIGINT}, </if> <if test="num != null"> num = #{num,jdbcType=INTEGER}, </if> <if test="barcode != null"> barcode = #{barcode,jdbcType=VARCHAR}, </if> <if test="image != null"> image = #{image,jdbcType=VARCHAR}, </if> <if test="cid != null"> cid = #{cid,jdbcType=BIGINT}, </if> <if test="status != null"> status = #{status,jdbcType=TINYINT}, </if> <if test="created != null"> created = #{created,jdbcType=TIMESTAMP}, </if> <if test="updated != null"> updated = #{updated,jdbcType=TIMESTAMP}, </if> </set> where id = #{id,jdbcType=BIGINT} </update> <update id="updateByPrimaryKey" parameterType="com.demo.pojo.TbItem"> update tb_item set title = #{title,jdbcType=VARCHAR}, sell_point = #{sellPoint,jdbcType=VARCHAR}, price = #{price,jdbcType=BIGINT}, num = #{num,jdbcType=INTEGER}, barcode = #{barcode,jdbcType=VARCHAR}, image = #{image,jdbcType=VARCHAR}, cid = #{cid,jdbcType=BIGINT}, status = #{status,jdbcType=TINYINT}, created = #{created,jdbcType=TIMESTAMP}, updated = #{updated,jdbcType=TIMESTAMP} where id = #{id,jdbcType=BIGINT} </update> </mapper> ``` 上面是逆向工程的mapper，后来我自己写了个TestMapper,还是出现同样的问题:  另外navicat访问数据库没问题。我想会不会是连接池配置的问题，也许那些配置可能导致这种情况？？

ssm框架中，同时连接多个数据库的问题

在ssm项目中，能通过配置连接两个或多个数据库吗，比如在mysql中有数据库A和数据库B 我想同时对两个数据库建立链接。能用select * from A.tableName,B.tableName查询到不同 数据库中的两个表的数据。

Mac os SSM框架链接数据库出现问题

查询数据库的时候报这个异常,但是在window电脑就没问题,单独用jdbc连接可以,但是用框架报这个错,数据库的密码也正确,MySQL的user也是root,是Macos的原因吗,求大神 ``` 十一月 05, 2019 11:28:53 下午 org.apache.catalina.core.StandardWrapperValve invoke 严重: Servlet.service() for servlet [dispatcherServlet] in context with path [/easyUI] threw exception [Request processing failed; nested exception is org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.exceptions.PersistenceException: ### Error querying database. Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; nested exception is org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (Access denied for user 'huang'@'localhost' (using password: YES)) ### The error may exist in class path resource [com/huibo/po/userMapper.xml] ### The error may involve com.huibo.dao.UserDao.select ### The error occurred while executing a query ### Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; nested exception is org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (Access denied for user 'huang'@'localhost' (using password: YES))] with root cause java.sql.SQLException: Access denied for user 'huang'@'localhost' (using password: YES) ```

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一个简单的评价系统，使用的SSM框架。 最近将项目迁移到liunx系统上（deepin 15.4） IDE是idea 数据库是 mysql 因为想测试docker的功能，将数据库迁移到了docker镜像上， **使用jdbc驱动的方式访问docker的数据库，一切正常。** 使用mybatis的数据连接池，访问失败，提示拒绝访问。一直得不到Connection。 非常疑惑 docker开放端口如下:  jdbc.properties 文件内容如下： ``` jdbc.driver=com.mysql.jdbc.Driver jdbc.url=jdbc:mysql://localhost:3303/teachercommentdb?useUnicode=true&characterEncoding=utf-8&serverTimezone=UTC jdbc.username=root jdbc.password=794613 ``` spring-mybatis配置整合文件内容如下： ``` <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd"> <!-- 自动扫描 --> <context:component-scan base-package="zyp"/> <!-- 第一种方式：加载一个properties文件 --> <bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"> <property name="location" value="classpath:jdbc.properties"/> </bean> <!-- 第二种方式：加载多个properties文件 <bean id="configProperties" class="org.springframework.beans.factory.config.PropertiesFactoryBean"> <property name="locations"> <list> <value>classpath:jdbc.properties</value> <value>classpath:common.properties</value> </list> </property> <property name="fileEncoding" value="UTF-8"/> </bean> <bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PreferencesPlaceholderConfigurer"> <property name="properties" ref="configProperties"/> </bean> --> <!-- 配置数据源 --> <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close"> <property name="driverClassName" value="${jdbc.driver}"/> <property name="url" value="${jdbc.url}"/> <property name="username" value="${jdbc.username}"/> <property name="password" value="${jdbc.password}"/> <!-- 初始化连接大小 --> <property name="initialSize" value="${initialSize}"/> <!-- 连接池最大数量 --> <property name="maxActive" value="${maxActive}"/> <!-- 连接池最大空闲 --> <property name="maxIdle" value="${maxIdle}"/> <!-- 连接池最小空闲 --> <property name="minIdle" value="${minIdle}"/> <!-- 获取连接最大等待时间 --> <property name="maxWait" value="${maxWait}"/> </bean> <!-- mybatis和spring完美整合，不需要mybatis的配置映射文件 --> <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <property name="dataSource" ref="dataSource"/> <!-- 自动扫描mapping.xml文件 --> <property name="mapperLocations" value="classpath:zyp/mapping/*.xml"/> </bean> <!-- DAO接口所在包名，Spring会自动查找其下的类 --> <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <property name="basePackage" value="zyp.dao"/> <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/> </bean> <!-- (事务管理)transaction manager, use JtaTransactionManager for global tx --> <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name="dataSource" ref="dataSource"/> </bean> <!-- (事务管理)transaction manager, use JtaTransactionManager for global tx --> <tx:annotation-driven transaction-manager="transactionManager"/> </beans> ``` 提示如下错误，但跟网上说明的原因不太一样，不是超时连接，也不是用户名错误等。 ``` Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; nested exception is org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (Communications link failure The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.)] with root cause java.net.ConnectException: 拒绝连接 (Connection refused) ```

SSM框架发送邮件的问题！

最近做项目SSM框架需要用发送邮件，以前没写过发送邮件，谁有这方面的思路 或者例子不吝赐教，我的需求是从数据库找到该条数据，然后往该注册邮箱里面发送该条数据，下面是度娘出来的东西，不知道用啥，直接跑java application能直接运行 到你所指定的邮箱，我数据库的值能抓出来然后不知道怎么往里面放了，不知道怎么写了，求大神指教一二 package me.reg.util; import java.util.Date; import java.util.Properties; import javax.mail.Session; import javax.mail.Transport; import javax.mail.internet.InternetAddress; import javax.mail.internet.MimeMessage; public class MailUtil { public static String myEmailAccount = "test1@lb.com"; public static String myEmailPassword = "123456"; // 发件人邮箱的 SMTP 服务器地址, 必须准确, 不同邮件服务器地址不同, 一般(只是一般, 绝非绝对)格式为: smtp.xxx.com // 网易163邮箱的 SMTP 服务器地址为: smtp.163.com public static String myEmailSMTPHost = "127.0.0.1"; // 收件人邮箱（替换为自己知道的有效邮箱） public static String receiveMailAccount = "test2@lb.com"; public static void sendTo(String body, String receiveMailAccount) throws Exception { //只需要传入正文和目标地址即可 Properties props = new Properties(); // 参数配置 props.setProperty("mail.transport.protocol", "smtp"); // 使用的协议（JavaMail规范要求） props.setProperty("mail.smtp.host", myEmailSMTPHost); // 发件人的邮箱的 SMTP // 服务器地址 props.setProperty("mail.smtp.auth", "true"); // 需要请求认证 // PS: 某些邮箱服务器要求 SMTP 连接需要使用 SSL 安全认证 (为了提高安全性, 邮箱支持SSL连接, 也可以自己开启), // 如果无法连接邮件服务器, 仔细查看控制台打印的 log, 如果有有类似 “连接失败, 要求 SSL 安全连接” 等错误, // 打开下面 /* ... */ 之间的注释代码, 开启 SSL 安全连接。 /* * // SMTP 服务器的端口 (非 SSL 连接的端口一般默认为 25, 可以不添加, 如果开启了 SSL 连接, // * 需要改为对应邮箱的 SMTP 服务器的端口, 具体可查看对应邮箱服务的帮助, // QQ邮箱的SMTP(SLL)端口为465或587, * 其他邮箱自行去查看) final String smtpPort = "465"; * props.setProperty("mail.smtp.port", smtpPort); * props.setProperty("mail.smtp.socketFactory.class", * "javax.net.ssl.SSLSocketFactory"); * props.setProperty("mail.smtp.socketFactory.fallback", "false"); * props.setProperty("mail.smtp.socketFactory.port", smtpPort); */ // 2. 根据配置创建会话对象, 用于和邮件服务器交互 Session session = Session.getDefaultInstance(props); session.setDebug(false); // 设置为debug模式, 可以查看详细的发送 log // 4. 根据 Session 获取邮件传输对象 Transport transport = session.getTransport(); // 3. 创建一封邮件 MimeMessage message = createMimeMessage(session, myEmailAccount, receiveMailAccount, body); // 4. 根据 Session 获取邮件传输对象 transport = session.getTransport(); // 5. 使用 邮箱账号 和 密码 连接邮件服务器, 这里认证的邮箱必须与 message 中的发件人邮箱一致, 否则报错 // // PS_01: 成败的判断关键在此一句, 如果连接服务器失败, 都会在控制台输出相应失败原因的 log, // 仔细查看失败原因, 有些邮箱服务器会返回错误码或查看错误类型的链接, 根据给出的错误 // 类型到对应邮件服务器的帮助网站上查看具体失败原因。 // // PS_02: 连接失败的原因通常为以下几点, 仔细检查代码: // (1) 邮箱没有开启 SMTP 服务; // (2) 邮箱密码错误, 例如某些邮箱开启了独立密码; // (3) 邮箱服务器要求必须要使用 SSL 安全连接; // (4) 请求过于频繁或其他原因, 被邮件服务器拒绝服务; // (5) 如果以上几点都确定无误, 到邮件服务器网站查找帮助。 // // PS_03: 仔细看log, 认真看log, 看懂log, 错误原因都在log已说明。 transport.connect(myEmailAccount, myEmailPassword); // 6. 发送邮件, 发到所有的收件地址, message.getAllRecipients() // 获取到的是在创建邮件对象时添加的所有收件人, // 抄送人, 密送人 transport.sendMessage(message, message.getAllRecipients()); // 7. 关闭连接 transport.close(); } public static MimeMessage createMimeMessage(Session session, String sendMail, String receiveMail, String body) throws Exception { // 1. 创建一封邮件 MimeMessage message = new MimeMessage(session); // 2. From: 发件人 message.setFrom(new InternetAddress(sendMail, "LB", "UTF-8")); // 3. To: 收件人（可以增加多个收件人、抄送、密送） message.setRecipient(MimeMessage.RecipientType.TO, new InternetAddress(receiveMail, "XX用户", "UTF-8")); // 4. Subject: 邮件主题 message.setSubject("激活您的帐号", "UTF-8"); // 5. Content: 邮件正文（可以使用html标签） message.setContent(body, "text/html;charset=UTF-8"); // 6. 设置发件时间 message.setSentDate(new Date()); // 7. 保存设置 message.saveChanges(); return message; } }

SSM框架，页面静置一段时间后，执行查询，从controller调用service函数没有立刻执行，之间隔了约20秒，怎么解决？

如题，查询页面静置一段时间后，大概5分钟，再次执行查询时，service函数没有立刻执行，可能是什么原因导致的？怎么解决？ 连接的数据库是Oracle。框架用的是SSM。 Controller： ``` @Controller @RequestMapping("/tcczbquery") public class ZBQueryController { @Autowired private ZBQueryService zbQueryService; @RequestMapping("/tccqueryzb.do") @ResponseBody public JSONObject queryZB(@RequestBody QueryCondition queryCondition){ System.out.println("开始----" + System.currentTimeMillis()); System.out.println(queryCondition); System.out.println("调用queryTargets----" + System.currentTimeMillis()); Result result = zbQueryService.queryTargets(queryCondition); System.out.println(JSON.toJSONString(result)); return JSON.parseObject(JSON.toJSONString(result)); } } ``` Service： ``` @Service @Transactional public class ZBQueryServiceImpl implements ZBQueryService { @Autowired private ZBConfigMapper zbConfigMapper; @Autowired private ZBQueryOrclMapper zbQueryOrclMapper; @Autowired private ZBQueryStsMapper zbQueryStsMapper; @Override public Result queryTargets(QueryCondition condition) { System.out.println("运行queryTargets----" + System.currentTimeMillis()); Result result = new Result(); return result; } } ``` 运行截图： 

JAVA 如何连接JanusGraph

例如SSM框架一样，通过配置文件连接到数据库。那么如何连接到JanusGraph呢， 用janusgraph-hbase这个包

ssm框架运维报错（数据库连接时出错）

今早发现了一个很奇怪的东西，服务器上前后测试了好几次的程序突然崩了，之前运行非常稳定，这是报错，目标是我数据库，大家有没有懂的 ``` 27-Mar-2018 07:34:41.680 严重 [https-jsse-nio2-443-exec-2] org.apache.catalina.core.StandardWrapperValve.invoke Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.dao.RecoverableDataAccessException: ### Error querying database. Cause: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: The last packet successfully received from the server was 32,986,781 milliseconds ago. The last packet sent successfully to the server was 32,986,781 milliseconds ago. is longer than the server configured value of 'wait_timeout'. You should consider either expiring and/or testing connection validity before use in your application, increasing the server configured values for client timeouts, or using the Connector/J connection property 'autoReconnect=true' to avoid this problem. ### The error may exist in file [C:\Program Files\Apache Software Foundation\Tomcat 9.0_Tomcat9.0\webapps2\ShowHTML\WEB-INF\classes\mapper\student_infoMapper.xml] ### The error may involve com.cn.fenyu.dao.student_infoMapper.selectByExample-Inline ### The error occurred while setting parameters ### SQL: select studentID, studentpw, power, studentname from student WHERE ( studentID = ? ) ### Cause: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: The last packet successfully received from the server was 32,986,781 milliseconds ago. The last packet sent successfully to the server was 32,986,781 milliseconds ago. is longer than the server configured value of 'wait_timeout'. You should consider either expiring and/or testing connection validity before use in your application, increasing the server configured values for client timeouts, or using the Connector/J connection property 'autoReconnect=true' to avoid this problem. ; SQL []; The last packet successfully received from the server was 32,986,781 milliseconds ago. The last packet sent successfully to the server was 32,986,781 milliseconds ago. is longer than the server configured value of 'wait_timeout'. You should consider either expiring and/or testing connection validity before use in your application, increasing the server configured values for client timeouts, or using the Connector/J connection property 'autoReconnect=true' to avoid this problem.; nested exception is com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: The last packet successfully received from the server was 32,986,781 milliseconds ago. The last packet sent successfully to the server was 32,986,781 milliseconds ago. is longer than the server configured value of 'wait_timeout'. You should consider either expiring and/or testing connection validity before use in your application, increasing the server configured values for client timeouts, or using the Connector/J connection property 'autoReconnect=true' to avoid this problem.] with root cause java.net.SocketException: Software caused connection abort: socket write error at java.net.SocketOutputStream.socketWrite0(Native Method) at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:111) at java.net.SocketOutputStream.write(SocketOutputStream.java:155) at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:82) at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:140) at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:3964) at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2596) at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2776) at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2838) at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2082) at com.mysql.jdbc.PreparedStatement.execute(PreparedStatement.java:1307) at com.mchange.v2.c3p0.impl.NewProxyPreparedStatement.execute(NewProxyPreparedStatement.java:989) at org.apache.ibatis.executor.statement.PreparedStatementHandler.query(PreparedStatementHandler.java:63) at org.apache.ibatis.executor.statement.RoutingStatementHandler.query(RoutingStatementHandler.java:79) at org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:63) at org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:324) at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:156) at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:109) at com.github.pagehelper.PageInterceptor.intercept(PageInterceptor.java:141) at org.apache.ibatis.plugin.Plugin.invoke(Plugin.java:61) at com.sun.proxy.$Proxy111.query(Unknown Source) at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:148) at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:141) at sun.reflect.GeneratedMethodAccessor72.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:433) at com.sun.proxy.$Proxy45.selectList(Unknown Source) at org.mybatis.spring.SqlSessionTemplate.selectList(SqlSessionTemplate.java:230) at org.apache.ibatis.binding.MapperMethod.executeForMany(MapperMethod.java:137) at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:75) at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:59) at com.sun.proxy.$Proxy46.selectByExample(Unknown Source) at com.cn.fenyu.servies.MainServies.finduser(MainServies.java:34) at com.cn.fenyu.controller.MainController.indexshow(MainController.java:149) at sun.reflect.GeneratedMethodAccessor90.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205) at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:133) at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:116) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738) at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970) at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861) at javax.servlet.http.HttpServlet.service(HttpServlet.java:634) at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846) at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ```

xmemcached和整合SSM框架 单元测试没问提 项目启动后造成mybatis连接不到数据库？

路径是没问提的 本来一切正常 我在原来的基础上整合了memcached。 memcached测试链接对数据进行操作没问题 但是项目运行起来以后 mybatis无法链接数据库； 注释掉memcached配置 就会回复正常 ## memcached.xml <!-- properties config --> <bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"> <property name="order" value="1" /> <property name="ignoreUnresolvablePlaceholders" value="true" /> <property name="locations"> <list> <value>classpath:config/memcached.properties</value> </list> </property> </bean> <!-- Memcached配置 --> <!-- p:connectionPoolSize="${memcached.connectionPoolSize}" p:failureMode="${memcached.failureMode}" --> <bean id="memcachedClientBuilder" class="net.rubyeye.xmemcached.XMemcachedClientBuilder"> <constructor-arg> <list> <bean class="java.net.InetSocketAddress"> <constructor-arg> <value>${memcached.server1.host}</value> </constructor-arg> <constructor-arg> <value>${memcached.server1.port}</value> </constructor-arg> </bean> </list> </constructor-arg> <constructor-arg> <list> <value>${memcached.server1.weight}</value> </list> </constructor-arg> <property name="commandFactory"> <bean class="net.rubyeye.xmemcached.command.TextCommandFactory" /> </property> <property name="sessionLocator"> <bean class="net.rubyeye.xmemcached.impl.KetamaMemcachedSessionLocator" /> </property> <property name="transcoder"> <bean class="net.rubyeye.xmemcached.transcoders.SerializingTranscoder" /> </property> <property name="connectionPoolSize" value="${memcached.connectionPoolSize}" /> <property name="failureMode" value="${memcached.failureMode}" /> </bean> <!-- Use factory bean to build memcached client --> <bean id="memcachedClient" factory-bean="memcachedClientBuilder" factory-method="build" destroy-method="shutdown" /> ## mybatis <!-- 引入配置文件 --> <bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"> <property name="location" value="classpath:config/jdbc.properties" /> </bean> <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close"> <property name="driverClassName" value="${driver}" /> <property name="url" value="${url}" /> <property name="username" value="${username}" /> <property name="password" value="${password}" /> <!-- 初始化连接大小 --> <property name="initialSize" value="${initialSize}"></property> <!-- 连接池最大数量 --> <property name="maxActive" value="${maxActive}"></property> <!-- 连接池最大空闲 --> <property name="maxIdle" value="${maxIdle}"></property> <!-- 连接池最小空闲 --> <property name="minIdle" value="${minIdle}"></property> <!-- 获取连接最大等待时间 --> <property name="maxWait" value="${maxWait}"></property> </bean> <!--spring与mybatis整合 --> <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <property name="dataSource" ref="dataSource" /> <!-- 自动扫描mapping.xml文件 --> <property name="mapperLocations" value="classpath:mapping/**/*.xml"> </property> <!-- 全局配置 --> <!-- 若不保留mybatis配置文件用上面那条替换这一条 --> <!-- <property name="configLocation" value="classpath:mybatis/sqlMapConfig.xml"/> --> <!-- mybatis配置文件路径 --> <property name="configLocation" value="classpath:/config/spring/mybatis.xml" /> </bean> <!-- DAO接口所在包名，Spring会自动查找其下的类 --> <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <!-- 扫描包路径，需要扫描多个包中间用逗号隔开 --> <property name="basePackage" value="com.ysjian.bud.app.dao,com.ysjian.bud.backstage.dao" /> <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"></property> </bean> ## 运行错误信息 org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.exceptions.PersistenceException: Error updating database. Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; nested exception is org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (Could not create connection to database server. Attempted reconnect 3 times. Giving up.) Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; nested exception is org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (Could not create connection to database server. Attempted reconnect 3 times. Giving up.) at org.mybatis.spring.MyBatisExceptionTranslator.translateExceptionIfPossible(MyBatisExceptionTranslator.java:75) at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:371) at com.sun.proxy.$Proxy16.delete(Unknown Source) at org.mybatis.spring.SqlSessionTemplate.delete(SqlSessionTemplate.java:268) at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:57) at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:52) at com.sun.proxy.$Proxy34.deleteSayHi(Unknown Source) at appLoginTest.BUDTest.Test1(BUDTest.java:46) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47) at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44) at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17) at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:74) at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:83) at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:72) at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:232) at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:89) at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238) at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63) at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236) at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53) at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229) at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61) at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:71) at org.junit.runners.ParentRunner.run(ParentRunner.java:309) at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:175) at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86) at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:539) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:761) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:461) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:207) Caused by: org.apache.ibatis.exceptions.PersistenceException: ### Error updating database. 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Giving up.) at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:26) at org.apache.ibatis.session.defaults.DefaultSqlSession.update(DefaultSqlSession.java:154) at org.apache.ibatis.session.defaults.DefaultSqlSession.delete(DefaultSqlSession.java:165) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:358) ... 34 more Caused by: org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; nested exception is org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (Could not create connection to database server. Attempted reconnect 3 times. Giving up.) at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:80) at org.mybatis.spring.transaction.SpringManagedTransaction.openConnection(SpringManagedTransaction.java:81) at org.mybatis.spring.transaction.SpringManagedTransaction.getConnection(SpringManagedTransaction.java:67) at org.apache.ibatis.executor.BaseExecutor.getConnection(BaseExecutor.java:279) at org.apache.ibatis.executor.SimpleExecutor.prepareStatement(SimpleExecutor.java:72) at org.apache.ibatis.executor.SimpleExecutor.doUpdate(SimpleExecutor.java:47) at org.apache.ibatis.executor.BaseExecutor.update(BaseExecutor.java:105) at org.apache.ibatis.executor.CachingExecutor.update(CachingExecutor.java:71) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.apache.ibatis.plugin.Plugin.invoke(Plugin.java:62) at com.sun.proxy.$Proxy54.update(Unknown Source) at org.apache.ibatis.session.defaults.DefaultSqlSession.update(DefaultSqlSession.java:152) ... 40 more Caused by: org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (Could not create connection to database server. Attempted reconnect 3 times. Giving up.) at org.apache.commons.dbcp.BasicDataSource.createDataSource(BasicDataSource.java:1225) at org.apache.commons.dbcp.BasicDataSource.getConnection(BasicDataSource.java:880) at org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:111) at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:77) ... 54 more Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 3 times. Giving up. at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source) at java.lang.reflect.Constructor.newInstance(Unknown Source) at com.mysql.jdbc.Util.handleNewInstance(Util.java:409) at com.mysql.jdbc.Util.getInstance(Util.java:384) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1013) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:987) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:973) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:918) at com.mysql.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:2405) at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2326) at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:832) at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46) at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source) at java.lang.reflect.Constructor.newInstance(Unknown Source) at com.mysql.jdbc.Util.handleNewInstance(Util.java:409) at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:417) at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:344) at org.apache.commons.dbcp.DriverConnectionFactory.createConnection(DriverConnectionFactory.java:38) at org.apache.commons.dbcp.PoolableConnectionFactory.makeObject(PoolableConnectionFactory.java:294) at org.apache.commons.dbcp.BasicDataSource.validateConnectionFactory(BasicDataSource.java:1247) at org.apache.commons.dbcp.BasicDataSource.createDataSource(BasicDataSource.java:1221) ... 57 more Caused by: java.sql.SQLException: Access denied for user 'DELL'@'localhost' (using password: YES) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1084) at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4232) at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4164) at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:926) at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1748) at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1288) at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2506) at com.mysql.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:2344) ... 71 more

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Attempted reconnect 3 times. Giving up. at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:526) at com.mysql.jdbc.Util.handleNewInstance(Util.java:406) at com.mysql.jdbc.Util.getInstance(Util.java:381) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:984) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:956) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:926) at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2270) at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:723) at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46) at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:526) at com.mysql.jdbc.Util.handleNewInstance(Util.java:406) at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:302) at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:282) at java.sql.DriverManager.getConnection(DriverManager.java:571) at java.sql.DriverManager.getConnection(DriverManager.java:187) at org.logicalcobwebs.proxool.DefaultConnectionBuilder.buildConnection(DefaultConnectionBuilder.java:39) at org.logicalcobwebs.proxool.Prototyper.buildConnection(Prototyper.java:159) at org.logicalcobwebs.proxool.Prototyper.sweep(Prototyper.java:102) at org.logicalcobwebs.proxool.PrototyperThread.run(PrototyperThread.java:44) Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure Last packet sent to the server was 0 ms ago. at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:526) at com.mysql.jdbc.Util.handleNewInstance(Util.java:406) at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1074) at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:335) at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2194) ... 15 more Caused by: java.net.ConnectException: Connection timed out: connect at java.net.DualStackPlainSocketImpl.connect0(Native Method) at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:79) at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:339) at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:200) at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:182) at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172) at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392) at java.net.Socket.connect(Socket.java:579) at java.net.Socket.connect(Socket.java:528) at java.net.Socket.<init>(Socket.java:425) at java.net.Socket.<init>(Socket.java:241) at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:253) at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:284) ... 16 more 2017-08-10 03:20:46 [Prototyper] ERROR org.logicalcobwebs.proxool.lvseu - Prototype com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 3 times. Giving up. at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:526) at com.mysql.jdbc.Util.handleNewInstance(Util.java:406) at com.mysql.jdbc.Util.getInstance(Util.java:381) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:984) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:956) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:926) at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2270) at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:723) at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46) at sun.reflect.GeneratedConstructorAccessor57.newInstance(Unknown Source) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:526) at com.mysql.jdbc.Util.handleNewInstance(Util.java:406) at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:302) at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:282) at java.sql.DriverManager.getConnection(DriverManager.java:571) at java.sql.DriverManager.getConnection(DriverManager.java:187) at org.logicalcobwebs.proxool.DefaultConnectionBuilder.buildConnection(DefaultConnectionBuilder.java:39) at org.logicalcobwebs.proxool.Prototyper.buildConnection(Prototyper.java:159) at org.logicalcobwebs.proxool.Prototyper.sweep(Prototyper.java:102) at org.logicalcobwebs.proxool.PrototyperThread.run(PrototyperThread.java:44) Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure Last packet sent to the server was 0 ms ago. at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:526) at com.mysql.jdbc.Util.handleNewInstance(Util.java:406) at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1074) at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:335) at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2194) ... 14 more Caused by: java.net.ConnectException: Connection timed out: connect at java.net.DualStackPlainSocketImpl.connect0(Native Method) at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:79) at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:339) at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:200) at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:182) at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172) at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392) at java.net.Socket.connect(Socket.java:579) at java.net.Socket.connect(Socket.java:528) at java.net.Socket.<init>(Socket.java:425) at java.net.Socket.<init>(Socket.java:241) at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:253) at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:284) ... 15 more

ssm框架配置多数据源，初始化后只加载了一个数据源，求大神指导！

数据源--dataAccessContext.xml <!-- 数据源定义,使用Apache DBCP 连接池 --> <bean id="dataSource" name="default_ds" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close"> <property name="driverClassName" value="${jdbc.cloudmaster.driverClassName}" /> <property name="url" value="${jdbc.cloudmaster.url}" /> <property name="username" value="${jdbc.cloudmaster.username}" /> <property name="password" value="${jdbc.cloudmaster.password}" /> <property name="initialSize" value="${jdbc.cloudmaster.initialSize}" /> <property name="maxActive" value="${jdbc.cloudmaster.maxActive}" /> <property name="maxIdle" value="${jdbc.cloudmaster.maxIdle}" /> <property name="minIdle" value="${jdbc.cloudmaster.minIdle}" /> <property name="validationQuery" value="${jdbc.cloudmaster.validationQuery}" /> </bean> <!-- monitoropenStack数据源定义,使用Apache DBCP 连接池--> <bean id="monitoropenStackDataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close"> <property name="driverClassName" value="${jdbc.openstack.driverClassName}"/> <property name="url" value="${jdbc.openstack.url}" /> <property name="username" value="${jdbc.openstack.username}" /> <property name="password" value="${jdbc.openstack.password}" /> <property name="initialSize" value="${jdbc.openstack.initialSize}"/> <property name="maxActive" value="${jdbc.openstack.maxActive}"/> <property name="maxIdle" value="${jdbc.openstack.maxIdle}"/> <property name="minIdle" value="${jdbc.openstack.minIdle}"/> <property name="validationQuery" value="${jdbc.openstack.validationQuery}"/> <property name="testWhileIdle" value="${jdbc.openstack.testWhileIdle}"/> <property name="timeBetweenEvictionRunsMillis" value="${jdbc.openstack.timeBetweenEvictionRunsMillis}"/> mybatis.xml <!-- cloudmaster数据源 --> <!-- cloudmaster数据源 --> <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean" > <property name="dataSource" ref="dataSource" /> <property name="configLocation" value="classpath:mybatis/mybatis-config.xml"></property> </bean> <bean id="mybatisDao" class="com.chinamobile.bcop.dao.impl.MybatisDAOImpl"> <qualifier value="mybatisDao"/> <property name="sqlSessionFactory" ref="sqlSessionFactory"></property> </bean> <!-- monitoropenStack数据源 --> <bean id="sqlSessionFactory_monitoropenStack" class="org.mybatis.spring.SqlSessionFactoryBean"> <property name="dataSource" ref="monitoropenStackDataSource" /> <property name="configLocation" value="classpath:mybatis/mybatis-config-monitor.xml"></property> </bean> <bean id="monitorMybatisDao" class="com.chinamobile.bcop.dao.impl.MybatisDAOImpl"> <qualifier value="monitorMybatisDao"/> <property name="sqlSessionFactory" ref="sqlSessionFactory_monitoropenStack"></property> </bean> service层注入 @Autowired @Qualifier("mybatisDao") private IMybatisDAO mybatisDao; @Autowired @Qualifier("monitorMybatisDao") private IMybatisDAO monitorMybatisDao; 在请求数据库做插入的时候monitorMybatisDao这个类的数据源和mybatisDao是同一个，求大神们给指导，哪里出现了问题？ 后面在service层断点进去发现，   在service层去掉第一个dao注入后，断点发现monitorMybatisDao的数据源仍然不对，大神们这是什么问题呢？

SSM框架——使用MyBatis Generator自动创建代码不成功

看的这个教程：http://blog.csdn.net/zhshulin/article/details/23912615 照着做配置也不成功，有些疑问 1，我看楼主的cmd命令，貌似他并没有把那几个jar包导入项目里啊，还是一个下载文件夹的路径，我也把他提供下载的这个文件夹，随便放在了D盘里，并按他说的，把generatorConfig.xml和这几个jar包放一起，我都不知道我在做什么( ╯□╰ ) 2，他的配置文件的第七行： <classPathEntry location="mysql-connector-java-5.1.25-bin.jar"/> ，引入了mysql数据库连接的jar包，这个jar包我在我的maven项目里下载过了，于是照猫画虎的写<classPathEntry location="mysql-connector-java-5.1.34.jar" />，然后命令行输入楼主指定的那段命令后报错，找不到我这个数据库连接：  这个数据库连接到底该怎么配啊？他光配了个jar文件名字也没说清楚

ssm框架连接配置applicationContext.xml运行时报错

**严重: Exception sending context initialized event to listener instance of class org.springframework.web.context.ContextLoaderListener org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.mybatis.spring.mapper.MapperScannerConfigurer#0' defined in class path resource [applicationContext.xml]: Initialization of bean failed; nested exception is java.lang.NoClassDefFoundError: org/apache/ibatis/session/SqlSessionFactory** at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:547) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475) at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:302) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:298) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:198) at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:116) at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:609) at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:464) at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:403) at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:306) at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:106) at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4727) at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5189) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:752) at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:728) at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:734) at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1107) at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:1841) at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:514) at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1135) at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635) at java.base/java.lang.Thread.run(Thread.java:844) **Caused by: java.lang.NoClassDefFoundError: org/apache/ibatis/session/SqlSessionFactory** at java.base/java.lang.Class.getDeclaredMethods0(Native Method) at java.base/java.lang.Class.privateGetDeclaredMethods(Class.java:3119) at java.base/java.lang.Class.privateGetPublicMethods(Class.java:3144) at java.base/java.lang.Class.getMethods(Class.java:1863) at org.springframework.beans.ExtendedBeanInfoFactory.supports(ExtendedBeanInfoFactory.java:54) at org.springframework.beans.ExtendedBeanInfoFactory.getBeanInfo(ExtendedBeanInfoFactory.java:46) at org.springframework.beans.CachedIntrospectionResults.<init>(CachedIntrospectionResults.java:275) at org.springframework.beans.CachedIntrospectionResults.forClass(CachedIntrospectionResults.java:188) at org.springframework.beans.BeanWrapperImpl.getCachedIntrospectionResults(BeanWrapperImpl.java:327) at org.springframework.beans.BeanWrapperImpl.getPropertyDescriptorInternal(BeanWrapperImpl.java:359) at org.springframework.beans.BeanWrapperImpl.isWritableProperty(BeanWrapperImpl.java:438) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1458) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1197) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:537) ... 24 more **Caused by: java.lang.ClassNotFoundException: org.apache.ibatis.session.SqlSessionFactory** at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1285) at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1119) ... 38 more db.properties文件,mysql8.0 ``` jdbc_username=root jdbc_password=aaa jdbc_driver=com.mysql.cj.jdbc.Driver jdbc_url=jdbc\:mysql\://localhost\:3306/aaaaa_db?useSSL\=false&serverTimezone\=GMT ``` applicationContext.xml代码如下 ``` <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p" xmlns:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop" xsi:schemaLocation= "http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.1.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd"> <!-- 配置扫描包 --> <context:component-scan base-package="com.ls.dao"/> <context:component-scan base-package="com.ls.service"/> <!-- 数据库连接相关配置 --> <!-- 加载配置文件 --> <context:property-placeholder location="classpath:conf/db.properties" /> <!-- 数据库连接池 --> <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource" destroy-method="close"> <property name="url" value="${jdbc_url}" /> <property name="username" value="${jdbc_username}" /> <property name="password" value="${jdbc_password}" /> <property name="driverClassName" value="${jdbc_driver}" /> <property name="maxActive" value="10" /> <property name="minIdle" value="5" /> </bean> <!-- 配置mybatis的sqlSessionFactory --> <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <property name="dataSource" ref="dataSource"/> <!-- 配置自动扫描mapper.xml文件 --> <property name="mapperLocations" value="classpath:com/ls/mapper/*.xml"/> <!-- mybatis的配置文件 --> <property name="configLocation" value="classpath:mybatis-config.xml"/> </bean> <!-- Dao接口所在包名,Spring会自动查找其下的类 --> <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <property name="basePackage" value="com.ls.dao"/> <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/> </bean> <!-- 配置事务管理器 --> <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name="dataSource" ref="dataSource"/> </bean> <!-- 配置事务管理器管理哪些方法 --> <!-- 配置事务通知属性 --> <tx:advice id="txAdvice" transaction-manager="transactionManager"> <!-- 定义事务传播属性 --> <tx:attributes> <tx:method name="insert*" propagation="REQUIRED" /> <tx:method name="add*" propagation="REQUIRED" /> <tx:method name="update*" propagation="REQUIRED" /> <tx:method name="upd*" propagation="REQUIRED" /> <tx:method name="save*" propagation="REQUIRED" /> <tx:method name="query*" propagation="REQUIRED" read-only="true" /> <tx:method name="get*" propagation="REQUIRED" read-only="true" /> <tx:method name="find*" propagation="REQUIRED" read-only="true" /> <tx:method name="*" propagation="REQUIRED" read-only="true" /> </tx:attributes> </tx:advice> <!-- 配置具体那些包下面的那些类下面的那些方法进行事务管理器 --> <aop:config> <aop:pointcut id="servicePoint" expression="execution(* com.service.*.*(..))" /> <aop:advisor advice-ref="txAdvice" pointcut-ref="servicePoint"/> </aop:config> </beans> ```

怎么查询候诊队列变化与否，实时更新客户端显示数据。

任务：做一个查询医院候诊队列实时显示到大屏幕。 前提：医院门诊系统服务器端是其他人写的，他不肯给我做接口，我要自己另外写一个查询候诊队列的基于SSM框架的服务器端和安卓客户端，与医院门诊系统用同一个数据库。一开始我在安卓客户端用Service+Thread轮询进行http请求，然后发现太耗资源，决定用websocket，让客户端与服务器端保持连接，如果数据库有更新，服务器端给客户端进行消息推送。 难题：我该怎么查询候诊队列，实时更新客户端的显示数据？我目前的做法是，在后端轮询，先将一开始查到的候诊队列保存到list1，服务器端定时查询候诊队列，保存到list2，两个list比较，如果两个list不同，则数据库发生了变化，通知客户端查询新数据。还有没有更好的办法，请各位大神搭救！！！

IDEA做SSM框架整合时，出现无法加载mapper，导致无法注入。

今日学习SSM框架整合，整合以后，单独用测试类可以连接成功连接数据库，可是一加入MVC用TOMCAT启动，项目就会报错，错误内容为：Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)} 以下为项目各部分截图，有没有大佬帮我分析下，问题到底出在哪？ ==========================================================================================================================================  ## 项目报错详细情况  ## spring配置文件已经配置了mapper.xml路径和齐对应的接口扫描包  ## 编译文件夹target里已经编译出了mapper相关配置文件及接口类  ## mapper.xml里的namespace已经指明了接口路径  ## pom文件里也配置了resource源 ========================================================================================================================================== # 详细代码已经贴在下方，只选了几个配置文件及mapper接口类，service及controller应该没关系就没传！ ============================================= # mybatis-config.xml ``` <?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd"> <configuration> <!--添加缓存 引入第三方二级缓存 --> <settings> <setting name="mapUnderscoreToCamelCase" value="true"/> <setting name="cacheEnabled" value="false"/> </settings> <!-- 配置数据源 default默认使用的数据源 --> <environments default="mysql"> <environment id="mysql"> <transactionManager type="JDBC" /> <dataSource type="POOLED"> <property name="driverClassName" value="com.mysql.jdbc.Driver"/> <property name="url" value="jdbc:mysql:///orderuser"/> <property name="username" value="zhijia3278"/> <property name="password" value="0528"/> </dataSource> </environment> </environments> <!-- 映射文件 --> <mappers> <mapper resource="OrderUserMapper.xml"/> </mappers> </configuration> ``` # OrderUserMapper.java ``` package cn.tedu.mapper; import cn.tedu.domain.Order; import cn.tedu.domain.User; public interface OrderUserMapper { public User queryUser(String userId); public Order queryOrder(String orderId); public void updateUserPoints(User user); } ``` # OrderUserMapper.xml ``` <?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd"> <mapper namespace="cn.tedu.mapper.OrderUserMapper"> <select id="queryUser" parameterType="String" resultType="User"> select * from t_user where user_id=#{userId} </select> <select id="queryOrder" parameterType="String" resultType="Order"> select * from t_order where order_id=#{orderId} </select> <update id="updateUserPoints" parameterType="User"> update t_user set points=#{points} where user_id=#{userId} </update> </mapper> ``` # spring.xml ``` <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:p="http://www.springframework.org/schema/p" xmlns:util="http://www.springframework.org/schema/util" xmlns:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd"> <!-- 配置内容 --> <context:component-scan base-package="cn.tedu"> </context:component-scan> <context:annotation-config></context:annotation-config> <!-- 持久层数据源 --> <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource"> <!-- 4个属性 --> <property name="driverClassName" value="com.mysql.jdbc.Driver"/> <property name="url" value="jdbc:mysql:///orderuser"/> <property name="username" value="zhijia3278"/> <property name="password" value="0528"/> </bean> <!-- sqlSession --> <bean id="sqlSession" class="org.mybatis.spring.SqlSessionFactoryBean"> <!-- 数据源注入 --> <property name="dataSource" ref="dataSource"/> <!-- 扫描mybatis的独立配置文件 关闭二级缓存,驼峰命名 --> <property name="configLocation" value="classpath:mybatis/mybatis-config.xml"/> <!-- 映射文件扫描 --> <property name="mapperLocations" value="classpath:mapper/OrderUserMapper.xml" /> <!-- 别名包 --> <property name="typeAliasesPackage" value="cn.tedu.domain"></property> </bean> <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <!-- 扫描的接口包 cn.tedu.mapper --> <property name="basePackage" value="cn.tedu.mapper"/> </bean> <!-- 注解驱动开启,@RequestMapping @RequestParam等 --> <mvc:annotation-driven/> <!-- 防止静态文件js css html访问被dispacherServlet拦截 --> <!-- localhost静态文件根目录 /static /js /css --> <!-- mapping 满足什么样子的访问地址 http://localhost:8080/js//1.js --> <mvc:resources location="/" mapping="/**"></mvc:resources> </beans> ``` # springmvc-servlet ``` <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:p="http://www.springframework.org/schema/p" xmlns:util="http://www.springframework.org/schema/util" xmlns:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd"> <!-- 配置内容 --> <context:component-scan base-package="cn.tedu"/> <!-- 注解驱动开启,@RequestMapping @RequestParam等 --> <mvc:annotation-driven/> <!-- 防止静态文件js css html访问被dispacherServlet拦截 --> <!-- localhost静态文件根目录 /static /js /css --> <!-- mapping 满足什么样子的访问地址 http://localhost:8080/js//1.js --> <mvc:resources location="/" mapping="/**"></mvc:resources> </beans> ``` # 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