java - Spring和MyBatis整合,Controller利用注解获取Service对象是Null
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问题描述
问 题
最近在学习整合Spring+MyBatis，最简单的配置，报这个错误：
Servlet.service() for servlet [dispatcher] in context with path [] threw exception [Request processing failed; nested exception is java.lang.NullPointerException] with root cause
1.applicationContext.xml:
<!-- 数据源配置, 使用Tomcat JDBC连接池 -->
<bean id="dataSource" class="org.apache.tomcat.jdbc.pool.DataSource" destroy-method="close">
<property name="driverClassName" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://localhost:3306/jsp_db"/>
<property name="name" value="root"/>
<property name="password" value=""/>
<property name="defaultAutoCommit" value="false" />
</bean>
<!-- 配置mybatis的配置文件位置 -->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSource" />
<!-- Mapper文件位置 -->
<property name="mapperLocations" value="/WEB-INF/config/mybatis/*Mapper.xml"/>
<!-- mybatis配置文件位置 -->
<property name="configLocation" value="/WEB-INF/config/mybatis/config.xml"/>
</bean>
<!--MapperScannerConfigurer自动扫描将Mapper接口生成代理注入到Spring -->
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<!-- 映射器接口文件的包路径， -->
<property name="basePackage" value="com.jackchan.dao" />
</bean>
2.Springmvc配置
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.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-3.0.xsd">
<!-- 加载包中的controller 注解扫描包 -->
<context:component-scan base-package="com.jackchan.controller"/>
</beans>3.MyBatis配置文件
<configuration>
<settings>
<setting name="cacheEnabled" value="true" />
</settings>
</configuration>
4.Mapper文件
<mapper namespace="com.jackchan.dao.IPTableDao">
<select id="selectAll" resultType="com.jackchan.entity.IPTable">
select * from table_ip
</select>
<select id="selectByCountry" parameterType="String" resultType="com.jackchan.entity.IPTable">
select * from table_ip where country=${country}
</select>
<select id="selectByISP" parameterType="String" resultType="com.jackchan.entity.IPTable">
select * from table_ip where isp=${isp}
</select>
</mapper>
5.DAO
@Repository
public interface IPTableDao {
List<IPTable> selectAllIP();
List<IPTable> selectByCountry(String country);
List<IPTable> selectByISP(String isp);
}
6.Service层
@Service
public class IPService {
@Resource
IPTableDao tableDao;
public String getIPData(String param) {
List<IPTable> tables = null;
if (param == "all") {
tables = tableDao.selectAllIP();
}else if (param == "country") {
tables = tableDao.selectByCountry(param);
}else {
tables = tableDao.selectByISP(param);
}
StringBuffer sBuffer = new StringBuffer();
for (IPTable tableIp : tables) {
sBuffer.append(tableIp.getIp()).append(":").append(tableIp.getPort()).append(",")
.append(tableIp.getCountry()).append(",").append(tableIp.getIsp());
sBuffer.append("\r\n");
}
return sBuffer.toString();
}
}
7.Controller层
@Controller()
@RequestMapping(value="/index")
public class IndexController {
@Resource
private IPService ipService;
@RequestMapping(value="/hello.html",method=RequestMethod.GET)
public void index(HttpServletRequest request,HttpServletResponse response) {
System.out.println("haha"+ipService);
String text = ipService.getIPData(request.getParameter("param"));
//ResponseUtil里封装了输出json格式数据方法
ResponseUtil.renderJson(response, text);
}
}
8.抛出的异常：
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'indexController': Injection of resource dependencies failed; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'ipService' is defined
at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.postProcessPropertyValues(CommonAnnotationBeanPostProcessor.java:311)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1214)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:543)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:305)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:301)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:196)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:772)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:834)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:537)
at org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:667)
at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:633)
at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:681)
at org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:552)
at org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:493)
at org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:136)
at javax.servlet.GenericServlet.init(GenericServlet.java:158)
at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1238)
at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1151)
at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:828)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:135)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:528)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1099)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:672)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1520)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1476)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'ipService' is defined
at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeanDefinition(DefaultListableBeanFactory.java:698)
at org.springframework.beans.factory.support.AbstractBeanFactory.getMergedLocalBeanDefinition(AbstractBeanFactory.java:1174)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:283)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:201)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:274)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:201)
at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.autowireResource(CommonAnnotationBeanPostProcessor.java:512)
at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.getResource(CommonAnnotationBeanPostProcessor.java:486)
at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor$ResourceElement.getResourceToInject(CommonAnnotationBeanPostProcessor.java:615)
at org.springframework.beans.factory.annotation.InjectionMetadata$InjectedElement.inject(InjectionMetadata.java:169)
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88)
at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.postProcessPropertyValues(CommonAnnotationBeanPostProcessor.java:308)
... 36 more
9.项目目录结构
望大家帮帮忙一下！
解决方案
报错应该不止这一行吧?一般这种报错都是一个带一个,一个带一个的,controller带出了service,service带出了dao,你把报错信息全贴出来看看.
spring的配置文件那个datasource为什么不写在上面呢,遵循从上到下的加载方式啊.
update: 评论不好上图. @jackchan
update: 评论不好上图. @jackchan
你把你的base-package后面的值中controller去掉在重启试试.你这仅仅是扫描了controller,并没有扫描service跟dao
你把你工程结构截图发一下看看...
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