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;
//自动装配
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;
} } 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 -->
<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> <!-- 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>
<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>
<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
login.jsp
<%@ 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
<%@taglib uri="/struts-tags" prefix="s" %>
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();
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
