wqq5610 2017-07-19 11:24 采纳率: 36.4%
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spring，springMVC，mybatis三大框架整合

debug时进入controller中的List list=itemsService.findItemsList(null) 报空指针异常

代码如下：

controller类：
package com.itcast.ssm.controller;

import java.util.List;

import javax.annotation.Resource;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;

import com.itcast.ssm.po.ItemsCustom;
import com.itcast.ssm.service.ItemsService;
import com.itcast.ssm.service.impl.ItemsServiceImpl;

@Controller
public class ItemsController {

@Resource
ItemsService itemsService;

@RequestMapping("/queryItems")
public ModelAndView queryItems()throws Exception{
    List<ItemsCustom> list=itemsService.findItemsList(null);

    ModelAndView modelAndView =new ModelAndView();
    modelAndView.addObject("itemsList",list);
    modelAndView.setViewName("items/itemsList");
    return modelAndView;
}

}

Service接口：
package com.itcast.ssm.service;

import java.util.List;

import com.itcast.ssm.po.ItemsCustom;
import com.itcast.ssm.po.ItemsQueryVo;

public interface ItemsService {
public List findItemsList(ItemsQueryVo itemsQueryVo)throws Exception;
}

Service实现：
package com.itcast.ssm.service.impl;
import java.util.List;
import javax.annotation.Resource;
import org.springframework.stereotype.Service;
import com.itcast.ssm.mapper.ItemsMapperCustom;
import com.itcast.ssm.po.ItemsCustom;
import com.itcast.ssm.po.ItemsQueryVo;
import com.itcast.ssm.service.ItemsService;

@Service
public class ItemsServiceImpl implements ItemsService {

@Resource
ItemsMapperCustom itemsMapperCustom;

public List<ItemsCustom> findItemsList(ItemsQueryVo itemsQueryVo)
        throws Exception {
    return itemsMapperCustom.findItemsList(itemsQueryVo);
}

}

mapper类：
package com.itcast.ssm.mapper;
import java.util.List;
import com.itcast.ssm.po.ItemsCustom;
import com.itcast.ssm.po.ItemsQueryVo;

public interface ItemsMapperCustom {

public List<ItemsCustom> findItemsList(ItemsQueryVo itemsQueryVo)throws Exception;

}

mapper.xml:

<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<sql id="items_test">
    <if test="ItemsCustom!=null">
        <if test="ItemsCustom.name!=null and ItemsCustom.name!=' ' ">
            items.name like '%${ItemsCustom.name}%'
        </if>
    </if>
</sql>
<select id="findItemsList" parameterType="com.itcast.ssm.po.ItemsQueryVo"
    resultType="com.itcast.ssm.po.ItemsCustom">
    select * from items
    <where>
        <include refid="items_test" />
    </where>
</select>

sqlMapConfig.xml配置：

<?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">

<typeAliases>
    <package name="com.itcast.ssm.po" />
</typeAliases>

applicationContext-do.xml:

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"
xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:jee="http://www.springframework.org/schema/jee" xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.0.xsd
http://www.springframework.org/schema/jee
http://www.springframework.org/schema/jee/spring-jee-4.0.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc.xsd
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context/spring-context.xsd">

<!-- 扫描配置文件 -->
<context:property-placeholder location="classpath:db.properties" />
<!-- 连接数据库 -->
<bean id="dataSource"
    class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    <property name="driverClassName" value="${jdbc.driver}" />
    <property name="url" value="${jdbc.url}" />
    <property name="username" value="${jdbc.name}" />
    <property name="password" value="${jdbc.psw}" />
</bean>
<!-- sqlSessionFactory -->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
    <!-- 连接池 -->
    <property name="dataSource" ref="dataSource" />
    <!-- 加载mybatis的全局配置文件 -->
    <property name="configLocation" value="classpath:mybatis/sqlMapConfig.xml" />
</bean>
<!-- mapper扫描 -->
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
    <property name="basePackage" value="com.itcast.ssm.mapper" />
    <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory" />
</bean>

事务控制：
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"
xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:jee="http://www.springframework.org/schema/jee" xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.0.xsd
http://www.springframework.org/schema/jee
http://www.springframework.org/schema/jee/spring-jee-4.0.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc.xsd
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context/spring-context.xsd">

<!-- 事务管理 -->
<bean id="transactionManager"
    class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
    <property name="dataSource" ref="dataSource" />
</bean>
<!-- 通知 -->
<tx:advice id="txAdvice" transaction-manager="transactionManager">
    <tx:attributes>
        <tx:method name="insert*" propagation="REQUIRED" />
        <tx:method name="update*" propagation="REQUIRED" />
        <tx:method name="edit*" propagation="REQUIRED" />
        <tx:method name="save*" propagation="REQUIRED" />
        <tx:method name="add*" propagation="REQUIRED" />
        <tx:method name="new*" propagation="REQUIRED" />
        <tx:method name="set*" propagation="REQUIRED" />
        <tx:method name="remove*" propagation="REQUIRED" />
        <tx:method name="delete*" propagation="REQUIRED" />
        <tx:method name="change*" propagation="REQUIRED" />
        <tx:method name="get*" propagation="SUPPORTS" read-only="true" />
        <tx:method name="find*" propagation="SUPPORTS" read-only="true" />
        <tx:method name="load*" propagation="SUPPORTS" read-only="true" />
        <tx:method name="*" propagation="SUPPORTS" read-only="true" />
    </tx:attributes>
</tx:advice>
<aop:config>
    <aop:advisor advice-ref="txAdvice"
        pointcut="execution(* com.itcast.ssm.service.impl.*.*(..))" />
</aop:config>

spring配置：
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"
xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:jee="http://www.springframework.org/schema/jee" xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.0.xsd
http://www.springframework.org/schema/jee
http://www.springframework.org/schema/jee/spring-jee-4.0.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc.xsd
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context/spring-context.xsd">

//为何使用组键扫描不到controller，只能单个配置

<!-- 视图解析器 -->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
    <property name="prefix" value="/WEB-INF/jsp/"/>
    <property name="suffix" value=".jsp"/>
</bean>

web.xml配置：

<?xml version="1.0" encoding="UTF-8"?>
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
wjnt

<!-- 加载spring容器 -->
<context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>/WEB-INF/classes/spring/applicationContext-*.xml</param-value>
</context-param>
<listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>

<servlet>
    <servlet-name>springMvc</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:spring/springmvc.xml</param-value>
    </init-param>
</servlet>
<servlet-mapping>
    <servlet-name>springMvc</servlet-name>
    <url-pattern>*.do</url-pattern>
</servlet-mapping>

<welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
</welcome-file-list>

  • 写回答

2条回答 默认 最新

  • niaonao 2017-07-19 16:51
    关注

    代码贴出来，截图也行

    评论

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