基于Annotation的Struts2+Spring3， Spring无法向acition中注入service
我在整合环境 Struts2.2.1 + Spring3.1.2 时，我的UserAction 的第16行user = userService.getUserByID("1");
userService始终为null，报NullPointerException ，不知如何回事，请大侠帮忙看看,谢谢！
所用lib：
aopalliance-1.0.jar
aspectjrt-1.7.0.jar
commons-fileupload-1.2.1.jar
commons-io-1.3.2.jar
commons-logging-1.1.1.jar
freemarker-2.3.16.jar
javassist-3.11.0.GA.jar
log4j-1.2.14.jar
ognl-3.0.jar
spring-aop-3.1.2.RELEASE.jar
spring-asm-3.1.2.RELEASE.jar
spring-beans-3.1.2.RELEASE.jar
spring-context-3.1.2.RELEASE.jar
spring-core-3.1.2.RELEASE.jar
spring-expression-3.1.2.RELEASE.jar
spring-jdbc-3.1.2.RELEASE.jar
spring-orm-3.1.2.RELEASE.jar
spring-tx-3.1.2.RELEASE.jar
spring-web-3.1.2.RELEASE.jar
struts2-convention-plugin-2.2.1.jar
struts2-core-2.2.1.jar
xwork-core-2.2.1.jar
---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>myWebApp</display-name>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
<!-- 配置spring的监听器 -->
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath*:applicationContext*.xml</param-value>
</context-param>
<!-- 开启监听 -->
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<!-- 配置Struts2 -->
<filter>
<filter-name>struts2</filter-name>
<filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
<init-param>
<param-name>struts.devMode</param-name>
<param-value>true</param-value>
</init-param>
<init-param>
<param-name>encoding</param-name>
<param-value>UTF-8</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>struts2</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
</web-app>
---Action-------------------------------------------------------------
1 package com.ibm.action;
2 import javax.annotation.Resource;
3 import org.apache.struts2.convention.annotation.Action;
4 import com.opensymphony.xwork2.ActionSupport;
5 import com.ibm.service.UserService;
6 import com.ibm.User;
7 public class UserAction extends ActionSupport {
8
9 private User user;
10
11 @Resource(name="userService")
12 private UserService userService;
13
14 @Action("/user/detail")
15 public String detail() throws Exception {
16 user = userService.getUserByID("1");
17 return SUCCESS;
18 }
19 }
---Service------------------------------------------------------------
package com.ibm.service;
import com.ibm.User;
public interface UserService {
User getUserByID(String id);
}
package com.ibm.service.impl;
import org.springframework.stereotype.Service;
import com.ibm.User;
import com.ibm.service.UserService;
@Service("userService")
public class UserServiceImpl implements UserService {
public User getUserByID(String id) {
User user = new User();
user.setAge(20);
user.setUserName("mike");
return user;
}
}
---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:aop="http://www.springframework.org/schema/aop"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-3.1.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-3.1.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.1.xsd
">
<bean class="org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor"/>
<context:component-scan base-package="com.ibm.service" /><!-- 扫描包 -->
<context:annotation-config/>
<!--问题应该出在这个xml，但不知如何解决-->
</beans>
[解决办法]
如果想使用@ Resource 、@ PostConstruct、@ PreDestroy等注解就必须声明CommonAnnotationBeanPostProcessor
把你的applicationContext.xml里的
<bean class="org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor"/>换成
<bean class="org.springframework.beans.factory.annotation.CommonAnnotationBeanPostProcessor"/>或者
<bean class="org.springframework.context.annotation.CommonAnnotationBeanPostProcessor" />
试试~
[解决办法]
<context:component-scan base-package="com.ibm.service" />
改为
<context:component-scan base-package="com.ibm" />
[解决办法]
<?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:tx="http://www.springframework.org/schema/tx"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:util="http://www.springframework.org/schema/util"
xmlns:p="http://www.springframework.org/schema/p"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-3.1.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-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/mvc
http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd
">
<mvc:annotation-driven />
<context:annotation-config/>
<context:component-scan base-package="com.ibm" />
[解决办法]
@Controller //------ 这要加这个
public class UserAction extends ActionSupport {
8
9 private User user;
10
11 @Resource(name="userService")
12 private UserService userService;
13
14 @Action("/user/detail")
15 public String detail() throws Exception {
16 user = userService.getUserByID("1");
17 return SUCCESS;
18 }
19 }
[解决办法]
Resource改成Autowired试试
[解决办法]
网页打开404你懂的，如何用mvn命令下载，求指教~
[解决办法]
你的Action类有问题！！
7 public class UserAction extends ActionSupport {
8
9 private User user;
10
11 @Resource(name="userService")
12 private UserService userService;
13
14 @Action("/user/detail")
15 public String detail() throws Exception {
16 user = userService.getUserByID("1");
17 return SUCCESS;
18 }
这个你们也太粗心了，声明了变量，为什么不给他们付get 和set方法，这样才能和前台相互传递值啊，否则当然会空指针，仔细想想基础问题吧
