struts2

Struts 2是一个MVC框架，以WebWork框架的设计思想为核心，吸收了Struts 1的部分优点.Struts 2拥有更加广阔的前景，自身功能强大，还对其他框架下开发的程序提供很好的兼容性。下面我们了解一下syruts2的应用

1.1引入架包

1.2创建loginAction类

package cn.happy.action; 
  
import java.util.Map; 
  
import javax.servlet.http.HttpSession; 
  
import org.apache.struts2.ServletActionContext; 
import org.apache.struts2.interceptor.SessionAware; 
  
import com.opensymphony.xwork2.Action; 
import com.opensymphony.xwork2.ActionContext; 
  
public class LoginAction implements Action,SessionAware{ 
    private Map<String,Object> map; 
    private String username; 
    private String password;    <BR>　　　　　//自动装配 
    <STRONG>public String execute() throws Exception { 
        if(username.equals("1")&&password.equals("1")){ 
              
            //解耦方式 (对Servlet Api进行封装 借助ActionContext) 
            Map<String,Object> session=ActionContext.getContext().getSession(); 
            session.put("uname", username); 
            //耦合方式 
//          HttpSession session2 = ServletActionContext.getRequest().getSession(); 
//          session2.setAttribute("uname",getUsername()); 
              
              
            return SUCCESS; 
        }else{ 
            return ERROR; 
        } 
          
    }</STRONG> 
  
      
    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 void setSession(Map<String, Object> map) { 
        this.map=map; 
    } 
  
}

1.3创建struts.xml文件

'<?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> 
  
    <!-- 修改文件 tomact不用重启 --> 
    <constant name="struts.devMode" value="true" /> 
  
    <package name="default" namespace="/" extends="struts-default"> 
  
        <!-- login action --> 
        <STRONG><action name="LoginAction" class="cn.happy.action.LoginAction"> 
            <result name="success">login/success.jsp</result> 
            <result name="login">login/login.jsp</result> 
            <result name="error">login/error.jsp</result> 
        </action></STRONG> 
  
  
        <!-- 第一个action --> 
        <action name="HelloWordAction" class="cn.happy.action.HelloWordAction"> 
            <result name="success">index.jsp</result> 
        </action> 
  
  
    </package> 
  
</struts>

1.4配置web.xml文件

<?xml version="1.0" encoding="UTF-8"?> 
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5"> 
  <display-name></display-name> 
  <STRONG><filter> 
    <filter-name>struts2</filter-name> 
    <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class> 
  </filter> 
  <filter-mapping> 
    <filter-name>struts2</filter-name> 
    <url-pattern>/*</url-pattern> 
  </filter-mapping></STRONG> 
  <welcome-file-list> 
    <welcome-file>login/login.jsp</welcome-file> 
  </welcome-file-list> 
</web-app>

1.5编写JSP页面

1.6在这里就展示一下登录页面与登录失败页面

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> 
<% 
String path = request.getContextPath(); 
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; 
%> 
<%@taglib uri="/struts-tags" prefix="s" %> 
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 
<html> 
  <head> 
    <base href="<%=basePath%>"> 
      
    <title>登录页面</title> 
      
      
  </head> 
    
  <body> 
    <s:form name="form1" namespace="/" method="post" action="LoginAction"> 
    请输入用户名： 
    <s:textfield name="username"></s:textfield><br/> 
      请输入密码： 
    <s:textfield name="password"></s:textfield> 
    <s:reset value="重填"></s:reset> 
    <s:submit value="登陆"></s:submit> 
    </s:form> 
  </body> 
</html>

在jsp中用到了Struts2 标签

引入

1	`<SPAN style="COLOR: #ff0000"><STRONG><%@taglib` `uri="/struts-tags"` `prefix="s"` `%></STRONG></SPAN>`

通用标签(条件,迭代)

1.7 success.jsp

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> 
<% 
String path = request.getContextPath(); 
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; 
%> 
  
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 
<html> 
  <head> 
    <base href="<%=basePath%>"> 
      
    <title>My JSP 'error.jsp' starting page</title> 
  
  </head> 
    
  <body> 
        <h1>登录失败</h1> 
     
        <h3>用户名或密码错误,请重新<a href="login/login.jsp">登录</a></h3> 
        <script>  
var t=10;//设定跳转的时间  
setInterval("refer()",1000); //启动1秒定时  
function refer(){  
if(t==0){  
location="http://localhost:8080/Day-login2-struts2/login/login.jsp"; //跳转的链接地址  
}  
document.getElementById('show').innerHTML=""+t+"秒后跳转到登录"; // 显示倒计时  
t--; // 计数器递减  
}  
</script>  
   <span id="show"></span>  
      
  </body> 
</html>

1.8结果展现

1.9登录成功用户名:1 密码:1

1.10 登录失败 10秒后会跳会登录

2.0拓展

当我们用到的属性多的时候都写在loginAction类中就会感觉到特别的凌乱,这个时候我们就可以创建一个类来管理这些属性(例:user)

package cn.happy.entity; 
  
public class User { 
    private String name; 
    private int age; 
      
    public int getAge() { 
        return age; 
    } 
    public void setAge(int age) { 
        this.age = age; 
    } 
    public String getName() { 
        return name; 
    } 
    public void setName(String name) { 
        this.name = name; 
    } 
      
      
    private String username; 
    private String password; 
    public String getUsername() { 
        return username; 
    } 
    public String getPassword() { 
        return password; 
    } 
    public void setUsername(String username) { 
        this.username = username; 
    } 
    public void setPassword(String password) { 
        this.password = password; 
    } 
      
  
}

这时候只在loginAction类中植入这个类就行了

private User user; 
    public User getUser() { 
        return user; 
    } 
    public void setUser(User user) { 
        this.user = user; 
    }

这样代码就会显得更加的清晰,岁然这样做会让我们的眼前一亮,事物都有两面性有利就有弊。我们用到的属性名前面都要加上管理它们类的名称（如:user.getUsername）

public class LoginAction implements Action,ModelDriven<User>{ 
  
    @Override
    public String execute() throws Exception { 
        if(user.getUsername().equals("1")&&(user.getPassword().equals("1"))){ 
            return SUCCESS;      
        }else{ 
            //失败回到登录 
            return LOGIN; 
        } 
    } 
    private User user; 
    public User getUser() { 
        return user; 
    } 
    public void setUser(User user) { 
        this.user = user; 
    } 
    @Override
    public User getModel() { 
        // TODO Auto-generated method stub 
        return user; 
    } 
}

在1.2中我们可以看到加粗字体的语句解耦与耦合的应用(在下一篇博客中会有详细解释解耦与耦合的你我他)

    //解耦方式  
    Map<String,Object> session=ActionContext.getContext().getSession();<BR>   session.put("uname", username); 
    //耦合方式 
    HttpSession session2 = ServletActionContext.getRequest().getSession(); 
　　    session2.setAttribute("uname",getUsername());

首先我们先要在登录成功页面配置一道(success.jsp)

<body> 
        欢迎你！${uname} 
 
 </body>

实现效果用户名为1　

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原文地址：https://www.cnblogs.com/LJN520/p/5960224.html