Struts2学习第六课 实现登录登出功能

关于Struts2请求的扩展名问题：

1).org.apache.struts2包下的default.properties中配置了struts2应用的一些常量

2).struts.action.extension定义了当前struts2应用可以接受的请求的扩展名。

3).可以在struts.xml文件中以常量配置的方式修改default.properties所配置的常量。

<constant name="struts.action.extension" value="action,do,"></constant>

直接看代码：

package logan.struts.study;

import java.util.Map;

import org.apache.struts2.dispatcher.SessionMap;
import org.apache.struts2.interceptor.ApplicationAware;
import org.apache.struts2.interceptor.SessionAware;

public class UserAction implements SessionAware,ApplicationAware{
    
    private Map<String, Object> session = null;
    private Map<String, Object> application = null;
    
    private String username;
    
    public void setUsername(String username) {
        this.username = username;
    }
    
    public String logout(){
        //数量减一
        Integer count = (Integer) application.get("count");
        if(count != null && count >0){
            count--;
            application.put("count", count);
        }
        count--;
        
        //session失效
        ((SessionMap)session).invalidate();
        
        return "logout-success";
    }
    
    public String execute(){
        
        //把用户信息存入Session域中
        
        //1.获取session，通过实现RequestAware接口
        
        //获取登录信息
        session.put("username", username);
        //把用户信息存入Session域中
        
        //
        Integer count = (Integer) application.get("count");
        if(count == null){
            count = 0;
        }
        //2.使当前在线人数 + 1
        count++;
        application.put("count", count);
        
        
        return "login-success";
    }

    @Override
    public void setSession(Map<String, Object> session) {
        // TODO Auto-generated method stub
        this.session = session;
        
    }

    @Override
    public void setApplication(Map<String, Object> application) {
        // TODO Auto-generated method stub
        this.application = application;
        
    }

}

struts.xml

<?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">

<struts>
    <!-- 配置Struts2可以受理的请求的扩展名 -->
    <constant name="struts.action.extension" value="action,do"></constant>
    <package name="default" namespace="/" extends="struts-default">
        <action name="login-ui">
            <result>/login.jsp</result>
        </action>
        
        <action name="user-login" class="logan.struts.study.UserAction">
            <result name="login-success">/login-success.jsp</result>
        </action>
        
        <action name="logout" class="logan.struts.study.UserAction"
        method="logout">
            <result name="logout-success">/login.jsp</result>
        </action>
    
    </package>
    
</struts>

web.xml

<?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">

<struts>
    <!-- 配置Struts2可以受理的请求的扩展名 -->
    <constant name="struts.action.extension" value="action,do"></constant>
    <package name="default" namespace="/" extends="struts-default">
        <action name="login-ui">
            <result>/login.jsp</result>
        </action>
        
        <action name="user-login" class="logan.struts.study.UserAction">
            <result name="login-success">/login-success.jsp</result>
        </action>
        
        <action name="logout" class="logan.struts.study.UserAction"
        method="logout">
            <result name="logout-success">/login.jsp</result>
        </action>
    
    </package>
    
</struts>

index.jsp

<?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">

<struts>
    <!-- 配置Struts2可以受理的请求的扩展名 -->
    <constant name="struts.action.extension" value="action,do"></constant>
    <package name="default" namespace="/" extends="struts-default">
        <action name="login-ui">
            <result>/login.jsp</result>
        </action>
        
        <action name="user-login" class="logan.struts.study.UserAction">
            <result name="login-success">/login-success.jsp</result>
        </action>
        
        <action name="logout" class="logan.struts.study.UserAction"
        method="logout">
            <result name="logout-success">/login.jsp</result>
        </action>
    
    </package>
    
</struts>

login-success.jsp

<?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">

<struts>
    <!-- 配置Struts2可以受理的请求的扩展名 -->
    <constant name="struts.action.extension" value="action,do"></constant>
    <package name="default" namespace="/" extends="struts-default">
        <action name="login-ui">
            <result>/login.jsp</result>
        </action>
        
        <action name="user-login" class="logan.struts.study.UserAction">
            <result name="login-success">/login-success.jsp</result>
        </action>
        
        <action name="logout" class="logan.struts.study.UserAction"
        method="logout">
            <result name="logout-success">/login.jsp</result>
        </action>
    
    </package>
    
</struts>

login.jsp

<?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">

<struts>
    <!-- 配置Struts2可以受理的请求的扩展名 -->
    <constant name="struts.action.extension" value="action,do"></constant>
    <package name="default" namespace="/" extends="struts-default">
        <action name="login-ui">
            <result>/login.jsp</result>
        </action>
        
        <action name="user-login" class="logan.struts.study.UserAction">
            <result name="login-success">/login-success.jsp</result>
        </action>
        
        <action name="logout" class="logan.struts.study.UserAction"
        method="logout">
            <result name="logout-success">/login.jsp</result>
        </action>
    
    </package>
    
</struts>

实现了简单的登录登出功能。