struts2框架学习笔记6：拦截器

package interceptor;

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

//拦截器的第一种创建方式
//拦截器的生命周期：随项目启动创建，随项目关闭而销毁
public class MyInterceptor implements Interceptor {

    @Override
    public void destroy() {
        // 销毁
        
    }

    @Override
    public void init() {
        // 初始化
        
    }

    @Override
    public String intercept(ActionInvocation arg0) throws Exception {
        // 拦截方法
        return null;
    }

}

package interceptor;

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

//第二种创建方式
public class MyInterceptor2 extends AbstractInterceptor {

    @Override
    public String intercept(ActionInvocation arg0) throws Exception {
        // 拦截方法
        return null;
    }

}

package interceptor;

import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.interceptor.MethodFilterInterceptor;
//方法过滤拦截器：定制拦截的方法
public class MyInterceptor3 extends MethodFilterInterceptor {

    @Override
    protected String doIntercept(ActionInvocation arg0) throws Exception {
        
        return null;
    }

}

package interceptor;

import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.interceptor.MethodFilterInterceptor;
//方法过滤拦截器：定制拦截的方法
public class MyInterceptor3 extends MethodFilterInterceptor {

    @Override
    protected String doIntercept(ActionInvocation invocation) throws Exception {
        //前处理
        System.out.println("前处理");
        //放行
        String result = invocation.invoke();
        //后处理
        System.out.println("后处理");
        return result;
    }

}

package interceptor;

import com.opensymphony.xwork2.ActionSupport;

public class Demo1Action extends ActionSupport {

    public String add() throws Exception {
        System.out.println("Demo1Action_add!");
        return SUCCESS;
    }
    
    public String delete() throws Exception {
        System.out.println("Demo1Action_delete!");
        return SUCCESS;
    }
    
    public String update() throws Exception {
        System.out.println("Demo1Action_update!");
        return SUCCESS;
    }
    
    public String find() throws Exception {
        System.out.println("Demo1Action_find!");
        return SUCCESS;
    }
    
}

<?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="inter" namespace="/" extends="struts-default" >
<interceptors>
    <!-- 1.注册拦截器 -->
        <interceptor name="myInter3" class="interceptor.MyInterceptor3"></interceptor>
    <!-- 2.注册拦截器栈 -->
        <interceptor-stack name="myStack">
            <!-- 自定义拦截器引入(建议放在20个默认拦截器之前) -->
            <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>
            <!-- 引用默认的拦截器栈(20个) -->
            <interceptor-ref name="defaultStack"></interceptor-ref>
        </interceptor-stack>    
    </interceptors>
    <!-- 3.指定包中的默认拦截器栈 -->
    <default-interceptor-ref name="myStack"></default-interceptor-ref>
    <action name="Demo1Action_*" class="interceptor.Demo1Action" method="{1}" >
        <!-- 为Action单独指定走哪个拦截器(栈) 
        <interceptor-ref name="myStack"></interceptor-ref>-->
        <result name="success" type="dispatcher" >/hello.jsp</result>
    </action>
    </package>
</struts>

        <global-results>
            <!-- 全局结果集配置 -->
            <result name="toLogin" type="redirect">/login.jsp</result>
        </global-results>
        <global-exception-mappings>
            <!-- 如果出现java.lang.RuntimeException异常,就将跳转到名为error的结果 -->
            <exception-mapping result="error"
                exception="java.lang.RuntimeException"></exception-mapping>
        </global-exception-mappings>