Spring 初学的简单问题。
本帖最后由 u011928511 于 2013-09-03 08:22:31 编辑 先晒错误：
java.lang.NullPointerException
cn.recx.action.loginAction.execute(loginAction.java:40)
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)

提示空指针异常。以下是代码：
/**
*beans.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-2.5.xsd
           http://www.springframework.org/schema/context
           http://www.springframework.org/schema/context/spring-context-2.5.xsd
           http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd
           http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd">

 <context:component-scan base-package="cn.recx"></context:component-scan>
</beans>

/**
*package cn.recx.beans
*UserBean.java
*/

package cn.recx.beans;

import org.springframework.stereotype.Repository;

@Repository
public class UserBean {
private String username;
private String password;
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}

}

/**
*package cn.recx.action
*loginAction.java
*/

package cn.recx.action;
 
 
import javax.annotation.Resource;

import cn.recx.beans.UserBean;

import com.opensymphony.xwork2.ActionSupport;

public class loginAction extends ActionSupport {

private static final long serialVersionUID = 1L;
@Resource public UserBean userBean;
private String username;
private String password;
public UserBean getUserBean() {
return userBean;
}

public void setUserBean(UserBean userBean) {
this.userBean = userBean;
}

public String getUsername() {
return username;
}

public void setUsername(String username) {
this.username = username;
}

public String getPassword() {
return password;
}

public void setPassword(String password) {
this.password = password;
}
public String execute() throws Exception {
System.out.println("1"+username+","+password);
userBean.setUsername(username);
userBean.setPassword(password);
 System.out.println("2"+userBean.getUsername()+userBean.getPassword());
return SUCCESS;
}

}

运行的时候System.out.println("1"+username+","+password);可以正常输出，说明struts2配置的没有错。但是下面的那个就不能正确输出了。
第40行是 userBean.setUsername(username); 这句。
找不到哪里错了。求解。 spring 异常 exception
[解决办法]
擦。。。struts2-spring-plugin.jar加上这个jar包，按上面我说的改，你没的这个插件，不能交给spring管理。