<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
登录界面
package com.zhang.action;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;
public class LoginAction extends ActionSupport {
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;
}
@Override
//返回的字符串是视图的入径
public String execute() throws Exception {
// TODO Auto-generated method stub
System.out.println("执行Action");
System.out.println("username");
if (username.equals("zhang")
&& password.equals("666") )
{
ActionContext.getContext().getSession().put("user",getUsername() );
return "success";
}
return "error";
}
}
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"
"http://struts.apache.org/dtds/struts-2.3.dtd">
<!-- Add packages here -->
<constant name="struts.devMode" value="true" />
<package name="default" namespace="/" extends="struts-default">
<action name="login" class="com.zhang.action.LoginAction">
<result name="error">/WEB-INF/error.jsp</result>
<result name="success">/WEB-INF/welcome.jsp</result>
</action>
</package>
错误提示：
Struts Problem Report
Struts has detected an unhandled exception:
Messages:
File: com/zhang/action/LoginAction.java
Line number: 31
Stacktraces
java.lang.NullPointerException
com.zhang.action.LoginAction.execute(LoginAction.java:31
