Struts2进阶学习4

自定义拦截器的使用

核心配置文件

<?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>

    <package name="index" namespace="/" extends="struts-default" >

        <interceptors>
            <!-- 注册拦截器 -->
            <interceptor name="myInter3" class="com.struts2.interceptor.MyInterceptor3"/>
            <!-- 注册拦截器栈 -->
            <interceptor-stack name="myStack">
                <!-- 自定义拦截器在默认之前(方便后面的拦截器对前面的也进行处理) -->
                <interceptor-ref name="myInter3">
                    <!-- 指定哪些方法不拦截 -->
                    <!--<param name="excludeMethods">add,delete</param>-->
                    <!-- 指定哪些方法需要拦截 -->
                    <param name="includeMethods">add,delete</param>
                </interceptor-ref>
                <!-- 引入struts2自带的20个拦截器 -->
                <interceptor-ref name="defaultStack"/>
            </interceptor-stack>
        </interceptors>
        <!-- 指定默认拦截器 -->
        <default-interceptor-ref name="myStack"/>

        <action name="IndexAction_*" class="com.struts2.action.IndexAction" method="{1}" >
            <result name="success" type="dispatcher" >/index.jsp</result>
        </action>
    </package>

    <package name="tag" namespace="/" extends="struts-default">
        <action name="DemoAction" class="com.struts2.action.DemoAction" method="page" >
            <result name="success" type="dispatcher" >/tag.jsp</result>
        </action>
    </package>

</struts>

struts.xml

自定义拦截器的3种方式

package com.struts2.interceptor;

import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.interceptor.Interceptor;

/**
 * @author: 肖德子裕
 * @date: 2018/11/21 15:48
 * @description: 自定义拦截器1
 * 拦截器生命周期：随项目启动而创建，随项目关闭而销毁
 */
public class MyInterceptor implements Interceptor {
    @Override
    public void init() {

    }

    @Override
    public String intercept(ActionInvocation actionInvocation) throws Exception {
        return null;
    }

    @Override
    public void destroy() {

    }
}

(1)

package com.struts2.interceptor;

import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.interceptor.AbstractInterceptor;
import com.opensymphony.xwork2.interceptor.Interceptor;

/**
 * @author: 肖德子裕
 * @date: 2018/11/21 15:48
 * @description: 自定义拦截器2
 */
public class MyInterceptor2 extends AbstractInterceptor {
    @Override
    public String intercept(ActionInvocation actionInvocation) throws Exception {
        return null;
    }
}

(2)

package com.struts2.interceptor;

import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.interceptor.AbstractInterceptor;
import com.opensymphony.xwork2.interceptor.MethodFilterInterceptor;

/**
 * @author: 肖德子裕
 * @date: 2018/11/21 15:48
 * @description: 自定义拦截器3
 * MethodFilterInterceptor:方法过滤拦截器
 */
public class MyInterceptor3 extends MethodFilterInterceptor {
    @Override
    protected String doIntercept(ActionInvocation actionInvocation) throws Exception {
        //前处理
        System.out.println("before>>>");
        //放行
        actionInvocation.invoke();
        //后处理
        System.out.println("after>>>");
        //跳转到成功页面
        return "success";
    }
}

(3)

测试拦截器

package com.struts2.action;

import com.opensymphony.xwork2.ActionSupport;

/**
 * @author: 肖德子裕
 * @date: 2018/11/21 15:45
 * @description: 测试拦截器的使用
 */
public class IndexAction extends ActionSupport {
    public String add(){
        System.out.println("添加用户!");
        return "success";
    }
    public String delete(){
        System.out.println("删除用户!");
        return "success";
    }
    public String update(){
        System.out.println("修改用户!");
        return "success";
    }
    public String find(){
        System.out.println("查找用户!");
        return "success";
    }
}

IndexAction

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<h2>I Love China</h2>
</body>
</html>

index.jsp

测试struts2标签的使用（了解）

package com.struts2.action;

import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;

import java.util.ArrayList;
import java.util.List;

/**
 * @author: 肖德子裕
 * @date: 2018/11/21 19:34
 * @description: 测试struts2标签的使用
 */
public class DemoAction extends ActionSupport {
    public String page(){
        List<String> list=new ArrayList<>();
        list.add("xdzy");
        list.add("xdzy");
        list.add("xdzy");
        list.add("xdzy");
        ActionContext.getContext().put("list",list);

        return SUCCESS;
    }
}

DemoAction

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="s" uri="/struts-tags" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<!-- 循环遍历 -->
<s:iterator value="#list">
    <s:property/><br>
</s:iterator>
<hr>
<s:iterator value="#list" var="name">
    <s:property value="#name"/><br>
</s:iterator>
<hr>
<s:iterator begin="1" end="100" step="1">
    <s:property/>|
</s:iterator>

<!-- if,else -->
<s:if test="#list.size()==4">
    list长度为4
</s:if>
<s:elseif test="#list.size()==3">
    list长度为3
</s:elseif>
<s:else>
    默认为0
</s:else>
</body>
</html>

tag.jsp