基于Struts2.1 annotation的Interceptor代码实例

查阅了网络上的文章，同时结合自己的实践，将今天的学习结果分享如下，欢迎大家拍砖。

/WEB-INF/lib/下包含以下jar包（但不只这两个）
struts2-core-2.1.6.jar
struts2-convention-plugin-2.1.6.jar

Interceptor代码如下：

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package com.kompin.kind.action;  
 
import java.util.Map;  
 
import com.opensymphony.xwork2.ActionContext;  
import com.opensymphony.xwork2.ActionInvocation;  
import com.opensymphony.xwork2.interceptor.AbstractInterceptor;  
 
public class AuthorityInterceptor extends AbstractInterceptor {  
 
    @Override 
    public String intercept(ActionInvocation invocation) throws Exception {  
        System.out.println("Enter AuthorityInterceptor");  
        Map session = ActionContext.getContext().getSession();  
        Object userId = session.get("userId");  
        if (userId == null)  
        {  
            return "login";  
        }  
        else 
        {  
            return invocation.invoke();  
        }  
    }  
 
} 
package com.kompin.kind.action;

import java.util.Map;

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

public class AuthorityInterceptor extends AbstractInterceptor {

 @Override
 public String intercept(ActionInvocation invocation) throws Exception {
  System.out.println("Enter AuthorityInterceptor");
  Map session = ActionContext.getContext().getSession();
  Object userId = session.get("userId");
  if (userId == null)
  {
   return "login";
  }
  else
  {
   return invocation.invoke();
  }
 }

}

struts.xml文件配置如下：

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<struts>  
 
    <constant name="struts.118n.encoding" value="GBK"/>  
    <constant name="struts.custom.i18n.resources" value="globalMessages"/>  
    <constant name="struts.convention.action.mapAllMatches" value="true"/>  
      
    <package name="kompinInterceptor" extends="struts-default">  
      
        <interceptors>  
            <interceptor name="authority"   
                class="com.kompin.kind.action.interceptor.AuthorityInterceptor"/>  
            <interceptor-stack name="auctionStack">  
                <interceptor-ref name="defaultStack"/>  
                <interceptor-ref name="authority"/>  
            </interceptor-stack>  
        </interceptors>         
          
        <default-interceptor-ref name="auctionStack"/>          
           
        <global-results>  
            <result name="login">/WEB-INF/jsp/login.jsp</result>  
            <result name="exception">/WEB-INF/jsp/error.jsp</result>  
        </global-results>  
          
    </package>       
       
</struts> 
<struts>

 <constant name="struts.118n.encoding" value="GBK"/>
 <constant name="struts.custom.i18n.resources" value="globalMessages"/>
 <constant name="struts.convention.action.mapAllMatches" value="true"/>
 
 <package name="kompinInterceptor" extends="struts-default">
 
  <interceptors>
   <interceptor name="authority"
    class="com.kompin.kind.action.interceptor.AuthorityInterceptor"/>
   <interceptor-stack name="auctionStack">
    <interceptor-ref name="defaultStack"/>
    <interceptor-ref name="authority"/>
   </interceptor-stack>
  </interceptors>  
  
  <default-interceptor-ref name="auctionStack"/>  
  
  <global-results>
   <result name="login">/WEB-INF/jsp/login.jsp</result>
   <result name="exception">/WEB-INF/jsp/error.jsp</result>
  </global-results>
  
 </package> 
 
</struts>

User action代码如下：

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package com.kompin.kind.action;  
 
import java.util.List;  
import java.util.Map;  
 
import org.apache.struts2.ServletActionContext;  
import org.apache.struts2.convention.annotation.Action;  
import org.apache.struts2.convention.annotation.InterceptorRefs;  
import org.apache.struts2.convention.annotation.InterceptorRef;  
import org.apache.struts2.convention.annotation.ParentPackage;  
import org.apache.struts2.convention.annotation.Result;  
import org.apache.struts2.convention.annotation.Results;  
 
import com.kompin.kind.business.UserBean;  
import com.kompin.kind.service.UserService;  
import com.opensymphony.xwork2.ActionContext;  
import com.opensymphony.xwork2.ActionSupport;  
 
@ParentPackage("kompinInterceptor")  
@InterceptorRefs({  
    @InterceptorRef("defaultStack")  
})  
@Results({  
  @Result(name="login", location="/WEB-INF/jsp/login.jsp")  
})  
public class UserAction extends ActionSupport {  
 
    private Integer id;  
    private String name;  
    private String pass;  
    private String email;  
    private UserService userSvc;  
    private List<UserBean> users;  
    private UserBean user;  
 
    @Action(value="/regist",  
            results={  
                @Result(name="success", type="dispatcher", location="/WEB-INF/jsp/login.jsp")  
                ,@Result(name="failure", type="dispatcher", location="/WEB-INF/jsp/failure.jsp")  
                ,@Result(name="input", type="dispatcher", location="/WEB-INF/jsp/regist.jsp")  
            }  
    )  
    public String regist()throws Exception{  
        try {  
            if(null == getName() ||null == getPass() || null == getEmail()){  
                return "input";  
            }  
            if (userSvc.addUser(getName(), getPass(), getEmail()) > 0) {  
                return "success";  
            }  
            return "failure";  
        } catch (Exception e) {  
            // TODO Auto-generated catch block  
            e.printStackTrace();  
            throw new Exception("注册用户出现异常");  
        }  
    }  
      
    @Action(value="/proShowUser",  
        interceptorRefs=@InterceptorRef("authority"),  
        results={  
            @Result(name="success", type="dispatcher", location="/WEB-INF/jsp/viewUser.jsp")  
            ,@Result(name="failure", type="dispatcher", location="/WEB-INF/jsp/failure.jsp")  
            ,@Result(name="input", type="dispatcher", location="/WEB-INF/jsp/login.jsp")  
        }  
    )     
    public String show()throws Exception{  
        try {  
            setUsers(userSvc.findAllUser());  
            return "success";  
        } catch (Exception e) {  
            // TODO Auto-generated catch block  
            e.printStackTrace();  
            throw new Exception("显示用户出现异常");  
        }  
    }  
    ...略...  
} 
package com.kompin.kind.action;

import java.util.List;
import java.util.Map;

import org.apache.struts2.ServletActionContext;
import org.apache.struts2.convention.annotation.Action;
import org.apache.struts2.convention.annotation.InterceptorRefs;
import org.apache.struts2.convention.annotation.InterceptorRef;
import org.apache.struts2.convention.annotation.ParentPackage;
import org.apache.struts2.convention.annotation.Result;
import org.apache.struts2.convention.annotation.Results;

import com.kompin.kind.business.UserBean;
import com.kompin.kind.service.UserService;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;

@ParentPackage("kompinInterceptor")
@InterceptorRefs({
 @InterceptorRef("defaultStack")
})
@Results({
  @Result(name="login", location="/WEB-INF/jsp/login.jsp")
})
public class UserAction extends ActionSupport {

 private Integer id;
 private String name;
 private String pass;
 private String email;
 private UserService userSvc;
 private List<UserBean> users;
 private UserBean user;

 @Action(value="/regist",
   results={
    @Result(name="success", type="dispatcher", location="/WEB-INF/jsp/login.jsp")
    ,@Result(name="failure", type="dispatcher", location="/WEB-INF/jsp/failure.jsp")
    ,@Result(name="input", type="dispatcher", location="/WEB-INF/jsp/regist.jsp")
   }
 )
 public String regist()throws Exception{
  try {
   if(null == getName() ||null == getPass() || null == getEmail()){
    return "input";
   }
   if (userSvc.addUser(getName(), getPass(), getEmail()) > 0) {
    return "success";
   }
   return "failure";
  } catch (Exception e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
   throw new Exception("注册用户出现异常");
  }
 }
 
 @Action(value="/proShowUser",
  interceptorRefs=@InterceptorRef("authority"),
  results={
   @Result(name="success", type="dispatcher", location="/WEB-INF/jsp/viewUser.jsp")
   ,@Result(name="failure", type="dispatcher", location="/WEB-INF/jsp/failure.jsp")
   ,@Result(name="input", type="dispatcher", location="/WEB-INF/jsp/login.jsp")
  }
 ) 
 public String show()throws Exception{
  try {
   setUsers(userSvc.findAllUser());
   return "success";
  } catch (Exception e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
   throw new Exception("显示用户出现异常");
  }
 }
 ...略...
}

Kind action代码如下：

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package com.kompin.kind.action;  
 
import java.util.List;  
 
import org.apache.struts2.ServletActionContext;  
import org.apache.struts2.convention.annotation.Action;  
import org.apache.struts2.convention.annotation.InterceptorRef;  
import org.apache.struts2.convention.annotation.InterceptorRefs;  
import org.apache.struts2.convention.annotation.ParentPackage;  
import org.apache.struts2.convention.annotation.Result;  
import org.apache.struts2.convention.annotation.Results;  
 
import com.kompin.kind.business.KindBean;  
import com.kompin.kind.service.KindService;  
import com.opensymphony.xwork2.ActionSupport;  
 
@ParentPackage("kompinInterceptor")  
@InterceptorRefs({  
    @InterceptorRef("auctionStack")  
})  
@Results({  
  @Result(name="login", location="/WEB-INF/jsp/login.jsp")  
})  
public class KindAction extends ActionSupport {  
      
    private KindService kindSvc;  
    private List kinds;  
    private String kindName;  
    private String kindDesc;  
    private KindBean kind;  
      
    /** 
     *  
     * @param kindSvc 
     */ 
    @Action(value="/proAddKind",  
            results={  
                @Result(name="success", type="chain", location="proViewKind")  
                ,@Result(name="failure", type="dispatcher", location="/WEB-INF/jsp/addKind.jsp")  
                ,@Result(name="input", type="dispatcher", location="/WEB-INF/jsp/addKind.jsp")  
            }  
    )  
    public String addKind()throws Exception{  
        try {  
            if (kindSvc.addKind(kindName, kindDesc) > 0) {  
                return "success";  
            }  
            return "input";  
        } catch (Exception e) {  
            // TODO Auto-generated catch block  
            e.printStackTrace();  
            return "input";  
        }  
    }  
    ...略...  
} 
package com.kompin.kind.action;

import java.util.List;

import org.apache.struts2.ServletActionContext;
import org.apache.struts2.convention.annotation.Action;
import org.apache.struts2.convention.annotation.InterceptorRef;
import org.apache.struts2.convention.annotation.InterceptorRefs;
import org.apache.struts2.convention.annotation.ParentPackage;
import org.apache.struts2.convention.annotation.Result;
import org.apache.struts2.convention.annotation.Results;

import com.kompin.kind.business.KindBean;
import com.kompin.kind.service.KindService;
import com.opensymphony.xwork2.ActionSupport;

@ParentPackage("kompinInterceptor")
@InterceptorRefs({
 @InterceptorRef("auctionStack")
})
@Results({
  @Result(name="login", location="/WEB-INF/jsp/login.jsp")
})
public class KindAction extends ActionSupport {
 
 private KindService kindSvc;
 private List kinds;
 private String kindName;
 private String kindDesc;
 private KindBean kind;
 
 /**
  *
  * @param kindSvc
  */
 @Action(value="/proAddKind",
   results={
    @Result(name="success", type="chain", location="proViewKind")
    ,@Result(name="failure", type="dispatcher", location="/WEB-INF/jsp/addKind.jsp")
    ,@Result(name="input", type="dispatcher", location="/WEB-INF/jsp/addKind.jsp")
   }
 )
 public String addKind()throws Exception{
  try {
   if (kindSvc.addKind(kindName, kindDesc) > 0) {
    return "success";
   }
   return "input";
  } catch (Exception e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
   return "input";
  }
 }
 ...略...
} 

要点说明：

1. @ParentPackage("kompinInterceptor")必须和struts.xml的package的name一致，否则启动tomcat会报错：

"Unable to find interceptor class referenced by ref-name ..."

2. 如果Action中并不是所有的方法都要auctionStack拦截，参考UserAction的代码：

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@InterceptorRefs({  
 @InterceptorRef("defaultStack")  
}) 
@InterceptorRefs({
 @InterceptorRef("defaultStack")
})

3. 如果Action中所有的方法都经过同一个拦截器拦截，，参考KindAction的代码：

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@InterceptorRefs({  
    @InterceptorRef("auctionStack")  
}) 
@InterceptorRefs({
 @InterceptorRef("auctionStack")
})

4. 如果Action中的某些方法需要特定的拦截器拦截，参考UserAction的代码（请留意proShowUser的Action注解与regist的Action注解的不同点）：

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@Action(value="/proShowUser",  
    interceptorRefs=@InterceptorRef("authority"),  
    results={  
        @Result(name="success", type="dispatcher", location="/WEB-INF/jsp/viewUser.jsp")  
        ,@Result(name="failure", type="dispatcher", location="/WEB-INF/jsp/failure.jsp")  
        ,@Result(name="input", type="dispatcher", location="/WEB-INF/jsp/login.jsp")  
    }  
) 
 @Action(value="/proShowUser",
  interceptorRefs=@InterceptorRef("authority"),
  results={
   @Result(name="success", type="dispatcher", location="/WEB-INF/jsp/viewUser.jsp")
   ,@Result(name="failure", type="dispatcher", location="/WEB-INF/jsp/failure.jsp")
   ,@Result(name="input", type="dispatcher", location="/WEB-INF/jsp/login.jsp")
  }
 )

5. 留意<interceptor-stack name="auctionStack">的定义。

本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/kompin_dmx/archive/2010/11/06/5992256.aspx