一．struts2框架整体流程
struts2-3.jpg
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二．第一个demo
１．创建被拦截的action
package com.lxf.timerintercepter;
/**
* 做一个耗时的actioin,用拦截器统计该action执行的时间
*/
import com.opensymphony.xwork2.ActionSupport;
public class TimerAction extends ActionSupport{
@Override
public String execute() throws Exception {
for(int i=0;i<10000;i++)
{
System.out.println("I LOVE IMOOC");
}
return SUCCESS;
}
}
２．创建拦截器
package com.lxf.timerintercepter;
/**
* 拦截器，用来计算timerAction的执行时间
*/
import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.interceptor.AbstractInterceptor;
public class TimerIntercepter extends AbstractInterceptor {
/**
* 自动调用此方法，进行拦截操作
*/
@Override
public String intercept(ActionInvocation invocation) throws Exception {
//１．执行Action之前
long start = System.currentTimeMillis(); //获得当前的毫秒值
//２．执行下一个拦截器，如果已经是最后一个拦截器，则执行目标action
String res = invocation.invoke();
//３．执行Action之后
long end = System.currentTimeMillis();
System.out.println("执行Action话费的时间：" + (end - start) + "ms");
//将最终调用Action之后的结果视图返回
return res;
}
}
３．在Timer.xml中注册和在对应action中引用拦截器
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd">
<struts>
<package name="default2" namespace="/myTimer" extends="struts-default">
<!-- 注册拦截器 -->
<interceptors>
<interceptor name="mytimer" class="com.lxf.timerintercepter.TimerIntercepter"></interceptor>
</interceptors>
<action name="timerAction" class="com.lxf.timerintercepter.TimerAction">
<result>/result.jsp</result>
<!-- 引用拦截器 -->
<interceptor-ref name="mytimer"></interceptor-ref>
</action>
</package>
</struts>
４．在struts.xml中包含timer.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd">
<struts>
<!-- 使用include标签引入各个模块xml配置文件 -->
<include file="helloworld.xml"></include>
<include file="helloworld2.xml"></include>
<!-- 引入测试action执行时间xml的配置文件 -->
<include file="timer.xml"></include>
<constant name="struts.i18n.encoding" value="UTF-8"></constant>
<!-- 使用感叹号方式配置多个method -->
<constant name="struts.enable.DynamicMethodInvocation" value="true"></constant>
<!-- 配置action后缀 -->
<constant name="struts.action.extension" value="html,action,do"></constant>
</struts>
５．将项目部署到tomcat上，访问地址：
http://localhost:8081/struts2-test1/myTimer/timerAction.action
查看控制台拦截器产生作用：
...
I LOVE IMOOC
I LOVE IMOOC
I LOVE IMOOC
执行Action话费的时间：29ms
三．struts2内置拦截器
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内置拦截器我们可以查看struts2核心jar包struts2-core-2.3.1.jar中的struts-default.xml
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在struts-default.xml中配置了默认拦截器栈
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所以推荐在自己显示为某个action引用拦截器之前，将默认拦截器栈先手动引用
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd">
<struts>
<package name="default2" namespace="/myTimer" extends="struts-default">
<!-- 注册拦截器 -->
<interceptors>
<interceptor name="mytimer" class="com.lxf.timerintercepter.TimerIntercepter"></interceptor>
</interceptors>
<action name="timerAction" class="com.lxf.timerintercepter.TimerAction">
<result>/result.jsp</result>
<!-- 为Action显示引用拦截器后，默认的拦截器defaultStack不在生效，需要手工引用 -->
<interceptor-ref name="defaultStack"></interceptor-ref>
<!-- 引用拦截器 -->
<interceptor-ref name="mytimer"></interceptor-ref>
</action>
</package>
</struts>
四．使用拦截器实现对用户登录验证
１．在WEB_INF目录中简历/page/manager.jsp，作为用户后台页面．
<%@ 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">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
后台管理页面，只有已登录的页面才能够访问！
</body>
</html>
２．写loginNew.jsp登录页
<%@ 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">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<h2>用户登陆</h2>
${loginError}
<form action="loginNew.action" method="post">
用户名：<input type="text" name="username" />
密码：<input type="password" name="password" />
<input type="submit" value="登录" />
</form>
</body>
</html>
３．写登录LoginNewAction.java
package com.lxf.action;
/**
* 用户登录页面，用来判断用户是否登录
*/
import java.util.Map;
import org.apache.struts2.interceptor.SessionAware;
import com.opensymphony.xwork2.ActionSupport;
public class LoginNewAction extends ActionSupport implements SessionAware{
private String username;
private String password;
private Map<String,Object> session;
/**
* 实现SessionAware中的接口
*/
@Override
public void setSession(Map<String, Object> session) {
this.session = session;
// TODO Auto-generated method stub
}
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;
}
/**
* 处理登录请求
*/
public String loginNew()
{
if("admin".equals(username) && "123".equals(password))
{
session.put("loginInfo", username);
return SUCCESS;
}else
{
session.put("loginError", "用户名或密码不正确!");
return ERROR;
}
}
}
４．写AuthIntercepter.java拦截器
package com.lxf.timerintercepter;
/**
* 拦截器，用来验证用户登录
*/
import java.util.Map;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.interceptor.AbstractInterceptor;
public class AuthIntercepter extends AbstractInterceptor {
/**
* 自动调用此方法，进行拦截操作
*/
@Override
public String intercept(ActionInvocation invocation) throws Exception {
ActionContext context = ActionContext.getContext();
Map<String,Object> session = context.getSession();
//用户已登录
if(session.get("loginInfo") !=null)
{
String result = invocation.invoke();
return result;
}else
//用户未登录
{
return "login";
}
}
}
４．配置自定义manager.xml配置文件：
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd">
<!-- 后台管理配置文件，判断用户登录 -->
<struts>
<package name="default5" namespace="/manager" extends="struts-default">
<!-- 注册拦截器 -->
<interceptors>
<interceptor name="auth" class="com.lxf.timerintercepter.AuthIntercepter"></interceptor>
<!-- 自定义拦截器栈myStack，组合了defaultStack和auth -->
<interceptor-stack name="myStack">
<interceptor-ref name="defaultStack"></interceptor-ref>
<interceptor-ref name="auth"></interceptor-ref>
</interceptor-stack>
</interceptors>
<!-- 通过Action访问后台管理页面，需要判断用户是否已登录，如果未登录则跳转到登录页 -->
<action name="auth">
<result>/WEB-INF/page/manager.jsp</result>
<result name="login">/loginNew.jsp</result>
<!-- 引用自定义拦截器栈 -->
<interceptor-ref name="myStack"></interceptor-ref>
</action>
<!-- 登录action -->
<action name="loginNew" class="com.lxf.action.LoginNewAction" method="loginNew">
<result>/WEB-INF/page/manager.jsp</result>
<result name="error">/loginNew.jsp</result>
</action>
</package>
</struts>
５．在struts.xml中引用manager.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd">
<struts>
<!-- 使用include标签引入各个模块xml配置文件 -->
<include file="helloworld.xml"></include>
<include file="helloworld2.xml"></include>
<!-- 引入测试action执行时间xml的配置文件 -->
<include file="timer.xml"></include>
<!-- 引入后台管理配置文件，判断用户登录xml -->
<include file="manager.xml"></include>
<constant name="struts.i18n.encoding" value="UTF-8"></constant>
<!-- 使用感叹号方式配置多个method -->
<constant name="struts.enable.DynamicMethodInvocation" value="true"></constant>
<!-- 配置action后缀 -->
<constant name="struts.action.extension" value="html,action,do"></constant>
<!-- 打开开发模式 -->
<constant name="struts.devMode" value="true"></constant>
</struts>
６．在没有登录的情况下，访问：
http://localhost:8081/struts2-test1/manager/auth.action
过滤器会判断是否登录，如果登录了则跳转套manager.jsp页面，否则跳转套登录页面
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