struts2学笔记十拦截器-优快云博客

本文链接：https://blog.youkuaiyun.com/facepp/article/details/6130762

本文详细介绍了Struts2框架中的拦截器实现，包括简单拦截器、方法过滤拦截器及权限控制拦截器的设计与配置。通过示例展示了如何自定义拦截器逻辑，设置拦截器顺序及实现基于用户权限的访问控制。

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7.3简单拦截器
package lee;

import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.interceptor.AbstractInterceptor;
import java.util.*;

/**
* @author yeeku.H.lee kongyeeku@163.com
* @version 1.0
* <br>Copyright (C), 2005-2008, yeeku.H.Lee
* <br>This program is protected by copyright laws.
* <br>Program Name:
* <br>Date:
*/
public class SimpleInterceptor extends AbstractInterceptor
{
private String name;
public void setName(String name)
{
this.name = name;
}

    public String intercept(ActionInvocation invocation) throws Exception
{
  LoginAction action = (LoginAction)invocation.getAction();
  System.out.println(name + " 拦截器的动作---------" + "开始执行登陆Action的时间为：" + new Date());
  long start = System.currentTimeMillis();
  String result = invocation.invoke();
  System.out.println(name + " 拦截器的动作---------" + "执行完登陆Action的时间为：" + new Date());
  long end = System.currentTimeMillis();
  System.out.println(name + " 拦截器的动作---------" + "执行完该Action的事件为" + (end - start) + "毫秒");
  return result;
    }
}

struts.xml
<?xml version="1.0" encoding="GBK"?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd">
<struts>
<constant name="struts.custom.i18n.resources" value="globalMessages"/>
<constant name="struts.i18n.encoding" value="GBK"/>

    <package name="lee" extends="struts-default">
  <interceptors>
   <interceptor name="mysimple" class="lee.SimpleInterceptor">
    <param name="name">简单拦截器</param>
   </interceptor>
  </interceptors>

        <action name="login" class="lee.LoginAction">
            <result name="error">/error.jsp</result>
            <result name="success">/welcome.jsp</result>

<interceptor-ref name="defaultStack"/>
   <interceptor-ref name="mysimple">
    <param name="name">改名后的拦截器</param>
   </interceptor-ref>
        </action>
    </package>
</struts>

7.4深入拦截器

1方法过滤
package lee;

import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.interceptor.MethodFilterInterceptor;
import java.util.*;

public class MyFilterInterceptor extends MethodFilterInterceptor

{
private String name;
public void setName(String name)
{
this.name = name;
}

public String doIntercept(ActionInvocation invocation)
  throws Exception
{
  LoginAction action = (LoginAction)invocation.getAction();
  System.out.println(name + " 拦截器的动作---------" + "开始执行登陆Action的时间为：" + new Date());
  long start = System.currentTimeMillis();
  String result = invocation.invoke();
  System.out.println(name + " 拦截器的动作---------" + "执行完登陆Action的时间为：" + new Date());
  long end = System.currentTimeMillis();
  System.out.println(name + " 拦截器的动作---------" + "执行完该Action的事件为" + (end - start) + "毫秒");
  return result;
}

}

    <package name="lee" extends="struts-default">
  <interceptors>
   <interceptor name="myfilter" class="lee.MyFilterInterceptor">
    <param name="name">方法过滤拦截器</param>
   </interceptor>

</interceptors>

        <action name="login" class="lee.LoginAction">
            <result name="error">/error.jsp</result>
            <result name="success">/welcome.jsp</result>

<interceptor-ref name="defaultStack"/>
   <interceptor-ref name="myfilter">
    <param name="name">改名后的方法过滤拦截器</param>
    <param name="excludeMethods">haha</param>
    <param name="includeMethods">execute</param>

   </interceptor-ref>
        </action>
    </package>
</struts>

excludeMethods 过滤掉方法为haha
includeMethods 对execute方法进行拦截

2拦截器的顺序
如果是在拦截方法之前，则配置在前面的拦截器，会先对用户的请求起作用。如果是在拦截方法之后，则配置在后面的拦截器，会先对用户的请求起作用。
例如:
<interceptor-ref name="defaultStack"/>
   <interceptor-ref name="mysimple">
    <param name="name">第一个</param>
   </interceptor-ref>
   <interceptor-ref name="mysimple">
    <param name="name">第二个</param>
   </interceptor-ref>

结果:
第一个拦截器的动作---------开始执行登陆Action的时间为：Wed Jan 12 10:17:16 CST 2011
第二个拦截器的动作---------开始执行登陆Action的时间为：Wed Jan 12 10:17:16 CST 2011
进入execute方法执行体..........
第二个拦截器的动作---------执行完登陆Action的时间为：Wed Jan 12 10:17:24 CST 2011
第二个拦截器的动作---------执行完该Action的事件为8522毫秒
第一个拦截器的动作---------执行完登陆Action的时间为：Wed Jan 12 10:17:24 CST 2011
第一个拦截器的动作---------执行完该Action的事件为8522毫秒

3拦截结果的监听器
public class MyPreResultListener implements PreResultListener
{
public void beforeResult(ActionInvocation invocation,String resultCode)
{
System.out.println("返回的逻辑视图为:" + resultCode);
}
}

配置中没有配置,怎么对跳转的结果进行拦截?
execute方法执行之前的拦截...
进入execute方法执行体..........
返回的逻辑视图为:error
execute方法执行之后的拦截......

4 ...*

5拦截器实现权限控制
package lee;
import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.ActionSupport;
import com.opensymphony.xwork2.Action;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.interceptor.AbstractInterceptor;
import java.util.*;
public class AuthorityInterceptor extends AbstractInterceptor
{
    public String intercept(ActionInvocation invocation) throws Exception
{
  ActionContext ctx = invocation.getInvocationContext();
  Map session = ctx.getSession();
  String user = (String)session.get("user");
  if (user != null && user.equals("pp") )
  {
   return invocation.invoke();
  }
  ctx.put("tip" , "您还没有登陆，请输入pp,911r登陆系统");
  return Action.LOGIN;
    }
}
<?xml version="1.0" encoding="GBK"?>
<!DOCTYPE struts PUBLIC
        "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
        "http://struts.apache.org/dtds/struts-2.0.dtd">
<struts>
<constant name="struts.custom.i18n.resources" value="globalMessages"/>
<constant name="struts.i18n.encoding" value="GBK"/>

  <global-results>
            <result name="login">/login.jsp</result>
  </global-results>

<action name="login" class="lee.LoginAction">
            <result name="error">/error.jsp</result>
            <result name="success">/welcome.jsp</result>
        </action>
        <action name="viewBook">
            <result>/WEB-INF/jsp/viewBook.jsp</result>
   
   <interceptor-ref name="defaultStack"/>
   <interceptor-ref name="authority"/>
        </action>
    </package>
</struts>

页面中<a href="viewBook.action">查看作者李刚出版的图书</a>
点击链接时进入了拦截. 如果用户名为pp就可以跳转到 <result>/WEB-INF/jsp/viewBook.jsp</result>
${requestScope.tip}
否则提示
您还没有登陆，请输入pp,911登陆系统