问题遇到的现象和发生背景
Tomcat启动时报错,一直提示UserServiceImpl无法注入到Controller里面
问题相关代码
Controller
package com.xinc.controller;
import com.xinc.pojo.User;
import com.xinc.service.UserServiceImpl;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import java.util.List;
@Controller
public class WebController {
@Autowired
public UserServiceImpl us;
@RequestMapping("/")
public String toIndex(Model model) {
List<User> users = us.selectAllUser();
model.addAttribute("user", users);
return "index";
}
}
UserService
```java
package com.xinc.service;
import com.xinc.pojo.User;
import java.util.List;
public interface UserService {
List<User> selectAllUser();
}
UserServiceImpl
package com.xinc.service;
import com.xinc.dao.UserMapper;
import com.xinc.pojo.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;
@Service
public class UserServiceImpl implements UserService {
@Autowired
UserMapper userMapper;
@Override
public List<User> selectAllUser() {
List<User> users = userMapper.selectAllUser();
return users;
}
}
springmvc.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: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/context
https://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/mvc
https://www.springframework.org/schema/mvc/spring-mvc.xsd">
<context:component-scan base-package="com.xinc.controller"/>
<bean id="viewResolver" class="org.thymeleaf.spring5.view.ThymeleafViewResolver">
<property name="order" value="1"/>
<property name="characterEncoding" value="UTF-8"/>
<property name="templateEngine">
<bean class="org.thymeleaf.spring5.SpringTemplateEngine">
<property name="templateResolver">
<bean class="org.thymeleaf.spring5.templateresolver.SpringResourceTemplateResolver">
<!-- 视图前缀 -->
<property name="prefix" value="/WEB-INF/templates/"/>
<!-- 视图后缀 -->
<property name="suffix" value=".html"/>
<property name="templateMode" value="HTML5"/>
<property name="characterEncoding" value="UTF-8"/>
</bean>
</property>
</bean>
</property>
</bean>
<!-- 访问静态资源 -->
<mvc:default-servlet-handler/>
<!-- 开启注解驱动 -->
<mvc:annotation-driven />
</beans>
applicationContext.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: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.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd">
<!--引入数据库配置文件-->
<context:property-placeholder location="classpath:jdbc.properties"/>
<!-- 不扫描已由springmvc扫描的controller注解 -->
<context:component-scan base-package="com.xinc">
<context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
</context:component-scan>
<!-- 1) 获得数据库连接池对象,并交由 spring 同一管理 -->
<bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">
<!-- 连接数据库的驱动,连接字符串,用户名和登录密码-->
<property name="driverClassName" value="${jdbc.driver}"/>
<property name="url" value="${jdbc.url}"/>
<property name="username" value="${jdbc.username}"/>
<property name="password" value="${jdbc.password}"/>
</bean>
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSource"></property>
<property name="mapperLocations" value="classpath:mapper/UserMapper.xml"/>
<property name="configLocation" value="mybatis.xml"></property>
</bean>
<!--SqlSessionTemplate:就是我们使用的sqlSession-->
<bean id="userMapper" class="org.mybatis.spring.mapper.MapperFactoryBean">
<property name="mapperInterface" value="com.xinc.dao.UserMapper"/>
<property name="sqlSessionFactory" ref="sqlSessionFactory"/>
</bean>
<!--扫描dao包里的所有接口-->
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="basePackage" value="com.xinc.dao"></property>
</bean>
</beans>
pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<packaging>war</packaging>
<groupId>com.xinc</groupId>
<artifactId>SSM</artifactId>
<version>1.0-SNAPSHOT</version>
<properties>
<spring.version>5.3.1</spring.version>
</properties>
<build>
<resources>
<resource>
<directory>src/main/java</directory><!--所在的目录-->
<includes><!--包括目录下的.properties,.xml 文件都会扫描到-->
<include>**/*.properties</include>
<include>**/*.xml</include>
</includes>
<filtering>false</filtering>
</resource>
<resource>
<directory>src/main/resources</directory><!--所在的目录-->
<includes><!--包括目录下的.properties,.xml 文件都会扫描到-->
<include>**/*.properties</include>
<include>**/*.xml</include>
</includes>
<filtering>false</filtering>
</resource>
</resources>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>8</source>
<target>8</target>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.4.2</version>
<configuration>
<skipTests>true</skipTests>
</configuration>
</plugin>
</plugins>
</build>
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aspects</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-tx</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aop</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>5.3.1</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-beans</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-expression</artifactId>
<version>${spring.version}</version>
</dependency>
<!-- 日志 -->
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-classic</artifactId>
<version>1.2.3</version>
</dependency>
<!-- ServletAPI -->
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>3.1.0</version>
<scope>provided</scope>
</dependency>
<!-- Spring5和Thymeleaf整合包 -->
<dependency>
<groupId>org.thymeleaf</groupId>
<artifactId>thymeleaf-spring5</artifactId>
<version>3.0.12.RELEASE</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
<scope>test</scope>
</dependency>
</project>
运行结果及报错内容
28-Jan-2022 20:57:27.501 信息 [http-nio-8080-exec-5] org.apache.catalina.core.ApplicationContext.log Initializing Spring DispatcherServlet 'SSM'
28-Jan-2022 20:57:27.593 严重 [http-nio-8080-exec-5] org.apache.catalina.core.ApplicationContext.log Servlet[SSM]的Servlet.init()引发异常
org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'webController': Unsatisfied dependency expressed through field 'us'; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.xinc.service.UserServiceImpl' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:643)
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:119)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:399)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1415)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:608)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:531)
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:944)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:925)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:588)
at org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:702)
at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:668)
at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:716)
at org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:591)
at org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:530)
at org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:170)
at javax.servlet.GenericServlet.init(GenericServlet.java:158)
at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1152)
at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1097)
at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:768)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:128)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:544)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:135)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:698)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:364)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:624)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:831)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1650)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191)
at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:748)
我的解答思路和尝试过的方法
我找不到是哪里出了问题,配置上也看不出来错误,试了其他属性也无法注入