sprng mvc注解 service注入的问题 求救。。。

北风之神096 2013-04-23 11:33:41
最近在学spring mvc ，为新项目做技术储备
折腾了一个星期，总算有点眉目了，今天下午写了个例子，用了三层结构 controller service 还有DAO，但是运行后发现service没有注入，导致项目的功能运行不正常，调了半天还是没有结果。。。各位大神帮忙看看
好了，废话不多说，上代码。。。。

先是controller


package com.itsum.springmvcpt.bg.test.controller;





import java.util.Iterator;

import java.util.LinkedList;

import java.util.List;



import javax.validation.Valid;



import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.stereotype.Controller;

import org.springframework.validation.BindingResult;

import org.springframework.validation.FieldError;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RequestParam;

import org.springframework.web.servlet.ModelAndView;

import org.springframework.web.servlet.view.RedirectView;



import com.itsum.springmvcpt.bg.test.benas.dtos.User;

import com.itsum.springmvcpt.bg.test.services.Iservices.Iuserservice;

import com.itsum.springmvcpt.bg.test.services.serviceImpl.UserService;





@Controller

public class UserController {

	

	

	private Iuserservice service;

	

	

	public Iuserservice getService() {

		return service;

	}



	public void setService(Iuserservice service) {

		this.service = service;

	}



	@RequestMapping("/welcome")

	public ModelAndView welcome(){

		ModelAndView mv=new ModelAndView();

		System.out.println("service:  "+service);

		List<User> list=service.findByLimit(10);

		mv.addObject("list", list);

		mv.setViewName("welcome");

		return mv;

	}

}


然后是service接口:


package com.itsum.springmvcpt.bg.test.services.Iservices;



import java.util.List;



import com.itsum.springmvcpt.bg.test.benas.dtos.User;



public interface Iuserservice {

	

	public List<User> findByLimit(int limit);

	

}



service实现:


package com.itsum.springmvcpt.bg.test.services.serviceImpl;



import java.util.List;



import javax.annotation.Resource;



import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.stereotype.Service;

import org.springframework.transaction.annotation.Transactional;



import com.itsum.springmvcpt.bg.test.benas.dtos.User;

import com.itsum.springmvcpt.bg.test.dao.Idaos.UserDao;

import com.itsum.springmvcpt.bg.test.services.Iservices.Iuserservice;





@Service("service")

public class UserService implements Iuserservice{

	

	

	private UserDao dao;

	

	public UserDao getDao() {

		return dao;

	}

	public void setDao(UserDao dao) {

		this.dao = dao;

	}

	

	@Transactional

	public List<User> findByLimit(int limit){

		return dao.findByLimit(limit);

	}

	

}


DAO接口:


package com.itsum.springmvcpt.bg.test.dao.Idaos;



import javax.annotation.Resource;



import org.mybatis.spring.SqlSessionTemplate;



public class SuperDao {

	@Resource(name="sqlSession")

	public SqlSessionTemplate template;

}










package com.itsum.springmvcpt.bg.test.dao.Idaos;



import java.util.List;



import org.springframework.stereotype.Component;



import com.itsum.springmvcpt.bg.test.benas.dtos.User;



 

public interface UserDao {

	public List<User> findByLimit(int limit);

	

}


DAO实现:



package com.itsum.springmvcpt.bg.test.dao.daoImls;



import java.util.List;



import org.springframework.stereotype.Component;

import org.springframework.stereotype.Repository;



import com.itsum.springmvcpt.bg.test.benas.dtos.User;

import com.itsum.springmvcpt.bg.test.dao.Idaos.SuperDao;

import com.itsum.springmvcpt.bg.test.dao.Idaos.UserDao;







@Repository("dao") 

public class UserDaoImpl extends SuperDao implements UserDao {



	@Override

	public List<User> findByLimit(int limit) {

		System.out.println("数据查询情况:  "+this.template.selectList("User.findByLimit", limit).size());

		return this.template.selectList("User.findByLimit", limit);

		

	}



}



接下来自然是配置文件了,
web.xml:


<?xml version="1.0" encoding="UTF-8"?>

<web-app id="WebApp_ID" version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">

	<display-name>

	springmvcpt</display-name>

	<welcome-file-list>

		<welcome-file>/welcome</welcome-file>

	</welcome-file-list>

	

	<servlet-mapping>  

	    <servlet-name>default</servlet-name>  

	    <url-pattern>*.jpg</url-pattern>

	    <url-pattern>*.png</url-pattern>

	    <url-pattern>*.gif</url-pattern>

	    <url-pattern>*.css</url-pattern>

	    <url-pattern>*.js</url-pattern>

	    <url-pattern>*.swf</url-pattern>

	    <url-pattern>*.pdf</url-pattern>

	    <url-pattern>*.java</url-pattern>

	    <url-pattern>*.class</url-pattern>

	    <url-pattern>*.vm</url-pattern>

	</servlet-mapping>





  <!-- spring mvc 的前置servlet -->

	<servlet>  

	    <servlet-name>springMVC</servlet-name>  

	    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>  

	    <load-on-startup>1</load-on-startup>  

	</servlet>  

	<servlet-mapping>  

	    <servlet-name>springMVC</servlet-name>  

	    <url-pattern>/</url-pattern>  

	</servlet-mapping>  



  <!-- Spring Listener -->

	<context-param>

		<param-name>contextConfigLocation</param-name>

		<param-value>classpath*:spring.xml</param-value>

	</context-param>

	<listener>

		<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>

	</listener>

</web-app>


spring-servlet.xml:


<?xml version="1.0" encoding="UTF-8"?>

<beans xmlns="http://www.springframework.org/schema/beans"

 xmlns:context="http://www.springframework.org/schema/context"

 xmlns:p="http://www.springframework.org/schema/p"

 xmlns:mvc="http://www.springframework.org/schema/mvc"

 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">

     

      <context:component-scan base-package="com.itsum.springmvcpt.bg"/>

      

      <mvc:annotation-driven />

      

     <!-- 对模型视图名称的解析，在请求时模型视图名称添加前后缀 -->

     <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">

     	<property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/>

     	<property name="prefix" value="/WEB-INF/jsp/"/>

    	<property name="suffix" value=".jsp"/>

    	

     </bean>

</beans>



mybaties的配置文件:


<?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:p="http://www.springframework.org/schema/p" 

    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-3.0.xsd

	http://www.springframework.org/schema/context 

	http://www.springframework.org/schema/context/spring-context-3.0.xsd 

	http://www.springframework.org/schema/aop 

	http://www.springframework.org/schema/aop/spring-aop-3.0.xsd 

	http://www.springframework.org/schema/tx 

    http://www.springframework.org/schema/tx/spring-tx-3.0.xsd"

>

<tx:annotation-driven transaction-manager="transactionManager"/>

<context:annotation-config></context:annotation-config>

<context:component-scan base-package="com.itsum.springmvcpt.bg"/>



<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">

<property name="dataSource" ref="dataSource" />

<property name="configLocation" value="classpath:mybatis.xml"/>

</bean>



<bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">

<constructor-arg index="0" ref="sqlSessionFactory" />

</bean>



<bean id="transactionManager"

class="org.springframework.jdbc.datasource.DataSourceTransactionManager">

<property name="dataSource" ref="dataSource" />

</bean>



<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">

	<property name="driverClassName" value="com.mysql.jdbc.Driver"/>



	<property name="url" value="jdbc:mysql://127.0.0.1:3306/test"/> 

		<property name="username" value="root"/>

		<property name="password" value="root"/>

		<property name="maxWait"            value="1000" />

        <property name="initialSize"        value="5" />

        <property name="maxActive"          value="20" />

        <property name="maxIdle"            value="5" />

        <property name="testWhileIdle"      value="true" />

        <property name="timeBetweenEvictionRunsMillis"  value="15000" />

        <property name="numTestsPerEvictionRun"         value="20" />

        <property name="validationQuery"    value="SELECT 1 FROM DUAL" />

        <property name="removeAbandoned"    value="true" />

        <property name="removeAbandonedTimeout"         value="180" />



		 	<!-- 	

	<property name="url" value="jdbc:mysql://localhost:3306/demo"/>

	<property name="username" value="root"/>

	<property name="password" value="ushuaia"/>

	<property name="initialSize" value="5"/>

		<property name="maxActive" value="50"/>

		<property name="maxIdle" value="10"/>

		<property name="maxWait" value="20"/>

		<property name="minIdle" value="1"/>

		 -->

</bean>

</beans>

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北风之神096 2013-04-25
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引用 9 楼 lvzg_005 的回复:
首先给你一个案例DEMO Java code?12345678910111213@Servicepublic class MovieFinder { // ...} public class SimpleMovieLister { private MovieFinder movieFinder; @Autowired ……
试了下这个，就可以了 附上修改后的代码: controller: 
 @Resource(name="userService")
	 private Iuserservice service;
service： 
@Service("userService")
public class UserService implements Iuserservice{
	
	@Resource(name="userDao")
	private UserDao dao;
谢谢各位大神，结帖啦.....
北风之神096 2013-04-24
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嗯 我试试...
zhanghs886 2013-04-24
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contorller跟service里面各自引用的private Iuserservice service和private UserDao dao，必须用@Resource(name="service")，@Resource(name="dao")注解，才能实例化！
lvzg_005 2013-04-24
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首先给你一个案例DEMO 

@Service
public class MovieFinder {
	// ...
}

public class SimpleMovieLister {
	    
	private MovieFinder movieFinder;
	    @Autowired
	    public void setMovieFinder(MovieFinder movieFinder) {
		this.movieFinder = movieFinder;
	    }
	}
或者直接绑定到变量上，不用提供setter方法 @Autowired private MovieFinder movieFinder; service注解的参数name是用来表明bean的名称的 比如 @Service("myService") public class BizService { } 如果要自动装配这个bean，可以使用 @Service("myService") private BizService bizService
抱抱枯叶 2013-04-24
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你在contorller的 private UserDao dao;上面加上@Autowired试试
tianma630 2013-04-24
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你仔细看看UserController，private Iuserservice service;没加注解 肯定空指针了 UserService也是 里面的userdao也没加注解
北风之神096 2013-04-24
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求救啊
张子路 2013-04-24
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我印象spring mvc 的service接口要在 spring-servlet xml中配置一下 然后在 controller中 不是 set 注解 而是 @Resource(name="XXX")的方式，而xxx和xml的配置name对应。。。 你直接@Service.. 不知道对不对 我对spring mvc 也不太熟 以前看到过 ... 上网找找资料吧
北风之神096 2013-04-24
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引用 2 楼 caomadeaaa 的回复:
@auto.... @service @comp.... xml和 注解 只能使用一种 同时使用出错
那应该怎么写呢
zuxianghuang 2013-04-24
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在supperDao类上加@Repository @Resource public void setService(Iuserservice service) { this.service = service; }
woaini245693140 2013-04-24
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private UserServiceI userService;
public UserServiceI getUserService() {
return userService;
}
@Autowired
public void setUserService(UserServiceI userService) {
this.userService = userService;
}
要加自动注入的 @Autowired
woaini245693140 2013-04-24
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private UserServiceI userService;
public UserServiceI getUserService() {
return userService;
}
@Autowired
public void setUserService(UserServiceI userService) {
this.userService = userService;
}
要加自动注入的 @Autowired

chenshengqqq 2013-04-24
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在定义service 和 dao时候要加上 @Autowired private Iuserservice service; @Autowired private UserDao dao;
caomadeaaa 2013-04-23
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配置文件中需要扫描全包
caomadeaaa 2013-04-23
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@auto.... @service @comp.... xml和 注解 只能使用一种 同时使用出错
北风之神096 2013-04-23
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运行可以正常启动，但是在浏览器地址栏上输入http://localhost:8080/springmvcpt/welcome 就会报错，页面是这个:

HTTP Status 500 - Request processing failed; nested exception is java.lang.NullPointerException

type Exception report

message Request processing failed; nested exception is java.lang.NullPointerException

description The server encountered an internal error that prevented it from fulfilling this request.

exception

org.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.lang.NullPointerException
	org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:656)
	org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:549)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:717)

root cause

java.lang.NullPointerException
	com.itsum.springmvcpt.bg.test.controller.UserController.welcome(UserController.java:43)
	sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	java.lang.reflect.Method.invoke(Method.java:597)
	org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:176)
	org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:426)
	org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:414)
	org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:790)
	org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:719)
	org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:644)
	org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:549)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
打印service的内存地址发现： 
service:  null
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