Struts2 拦截器（二十三）

Struts2拦截器

最新推荐文章于 2023-04-30 00:38:07 发布

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#interceptor #文字拦截

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本文介绍了Struts2框架中的拦截器概念及应用实例，包括登录拦截器和内容过滤拦截器的实现方式。登录拦截器检查用户是否已登录，未登录则跳转到登录页面；内容过滤拦截器用于过滤用户发布内容中的敏感词汇。

1.什么是拦截器？
拦截器(interceptor) 是动态拦截Action调用的对象，在执行Action的业务逻辑处理方法execute 之前，Struts2中会首先执行struts.xml中引用的拦截器。

[b][color=red]Action拦截器[/color][/b]
2.做登录拦截用户名是否输入两种不通的拦截器
LoginInterceptor.java


package com.sh.interceptor;

import java.util.Map;

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

public class LoginInterceptor extends AbstractInterceptor {

	@Override
	public String intercept(ActionInvocation ai) throws Exception {
		Map session=ai.getInvocationContext().getSession();
		String username=(String) session.get("loginName");
		if(username!=null && username.length()>0){
			return ai.invoke();
		}
		else {
			ActionContext ac=ai.getInvocationContext();
			ac.put("popedom", "您还没有登录,请登录！");
			return Action.LOGIN;
		}

	}

}

LoginInterceptor2.java


package com.sh.interceptor;

import com.opensymphony.xwork2.Action;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.interceptor.Interceptor;
import com.sun.xml.internal.fastinfoset.stax.events.Util;

public class LoginInterceptor2 implements Interceptor {

	public void destroy() {
		// TODO Auto-generated method stub

	}

	public void init() {
		// TODO Auto-generated method stub

	}

	public String intercept(ActionInvocation invocation) throws Exception {
		ActionContext ac=ActionContext.getContext();
		String userName=(String)ac.getSession().get("loginName");
		if(!Util.isEmptyString(userName)){
			return invocation.invoke();
		}else{
			ac.put("error", "请输入用户名！");
			return Action.LOGIN;
		}
	}

}

4.struts.xml


<?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="default" extends="struts-default">
		<interceptors>
			<interceptor name="checkLogin" class="com.sh.interceptor.LoginInterceptor"/>
			<interceptor name="checkLogin2" class="com.sh.interceptor.LoginInterceptor2"/>
		</interceptors>
		<action name="checkLogin" class="com.sh.action.LoginAction">
			<result name="success">/success.jsp</result>
			<result name="login">/login.jsp</result>
			<interceptor-ref name="defaultStack"/>
			<interceptor-ref name="checkLogin2"/>		
		</action>
	</package>

</struts>

5.login.jsp



  <body>
    <center>
    	<h3>
    		${popedom}
    		${error}
    	</h3>
    	<s:form action="checkLogin" method="post">
    		<s:textfield name="loginName" label"loginName" />
    		<s:textfield name="loginPassword" label="loginPassword"/>    	
    		<s:submit/>
    		<s:token/>
    	</s:form>
    </center>
  </body>

[b][color=red]文字拦截器[/color][/b]
实例：网站论坛要求会员发帖的内容不能脏字，如果会员使用不文明语言，通常情况下，系统会自动使用“***”来替换。在Struts2Hogn可以使用拦截器来实现这个功能。案例拦截 "不"

ContentInterceptor.java


package com.sh.interceptor;

import com.opensymphony.xwork2.Action;
import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.interceptor.AbstractInterceptor;
import com.sh.action.publicAction;

public class ContentInterceptor extends AbstractInterceptor {

	@Override
	public String intercept(ActionInvocation invocation) throws Exception {
		Object obj=invocation.getAction();
		if(obj!=null){
			if(obj instanceof publicAction){
				publicAction pa=(publicAction)obj;
				String content=pa.getContent();
				if(content.contains("不")){
					content=content.replaceAll("不", "**");
					pa.setContent(content);
				}
				return invocation.invoke();
			}else {
				return Action.LOGIN;
			}
		}else{
			return Action.LOGIN;
		}
	}

}

struts.xml


<?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="default" extends="struts-default">
		<interceptors>
			<interceptor name="checkLogin" class="com.sh.interceptor.LoginInterceptor"/>
			<interceptor name="checkLogin2" class="com.sh.interceptor.LoginInterceptor2"/>
			<interceptor name="replace" class="com.sh.interceptor.ContentInterceptor"/>
		</interceptors>
		<action name="checkLogin" class="com.sh.action.LoginAction">
			<result name="success">/success.jsp</result>
			<result name="login">/login.jsp</result>
			<interceptor-ref name="defaultStack"/>
			<interceptor-ref name="checkLogin2"/>		
		</action>
		<action name="public" class="com.sh.action.publicAction">
			<result name="success">/success.jsp</result>
			<result name="login">/news.jsp</result>
			<interceptor-ref name="defaultStack"/>
			<interceptor-ref name="replace"/>
		</action>
	</package>

</struts>

news.jsp


 <body>
    <s:form action="public" method="post">
    		<s:textfield name="title" label="标题" />
    		<s:textarea name="content" cols="30" rows="5" label="内容"/>    	
    		<s:submit/>
    		<s:token/>
    	</s:form>
  </body>