struts2中方法拦截器(Interceptor)的中的excludeMethods与includeMethods的理解

参考：http://www.cnblogs.com/langtianya/archive/2013/04/10/3012205.html

通过对struts2的学习，对于interceptor中的excludeMethods与includeMethods的理解：

针对MethodFilterInterceptor：

excludeMethods表示排除指定的方法，即不对标记为excludeMethods的方法进行拦截，

includeMethods表示包含指定的方法，即对标记为includeMethods的方法进行拦截，

 

在struts.xml中关于excludeMethods和includeMethods有两种实现方式，一种相当于全局，另一种相当于局部，即<interceptors>

<interceptor name="method" class="com.yxl.interceptor.MethodInterceptor">

<param name="includeMethods">method1,method2</param>

</interceptor>

</interceptors>为全局

而 <interceptor-ref name="method">

<param name="excludeMethods">method1,method2</param>

</interceptor-ref> 

为局部，若全局中的param定义为excludeMethods同样局部中的param也定义为excludeMethods，则局部中的param生效，全局中的param无效，即被局部中的param覆盖，同样，若全局中的param定义为includeMethods同样局部中的param也定义为includeMethods，则局部中的param生效，全局中的param无效，即被局部中的param覆盖。

当全局中的param与局部中的param不相同的时，即当全局中param为excludeMethods而局部中的param为includeMethods和全局中的param为includeMethods而局部中param为excludeMethods，则标志为includeMethods生效，即若是全局中的param定义为includeMethods，则全局屏蔽局部，以全局为准，反之，以局部为准。

 

 

要实现自定义拦截器，需要继承MethodFilterInterceptor类。MethodFilterInterceptor类是AbstractInterceptor的子类，其源代码如下：

    protected transient Logger log = LoggerFactory.getLogger(getClass());  

      

    protected Set<String> excludeMethods = Collections.emptySet();  

    protected Set<String> includeMethods = Collections.emptySet();  

  

    public void setExcludeMethods(String excludeMethods) {  

        this.excludeMethods = TextParseUtil.commaDelimitedStringToSet(excludeMethods);  

    }  

      

    public Set<String> getExcludeMethodsSet() {  

        return excludeMethods;  

    }  

  

    public void setIncludeMethods(String includeMethods) {  

        this.includeMethods = TextParseUtil.commaDelimitedStringToSet(includeMethods);  

    }  

      

    public Set<String> getIncludeMethodsSet() {  

        return includeMethods;  

    }  

  

    @Override  

    public String intercept(ActionInvocation invocation) throws Exception {  

        if (applyInterceptor(invocation)) {  

            return doIntercept(invocation);  

        }   

        return invocation.invoke();  

    }  

  

    protected boolean applyInterceptor(ActionInvocation invocation) {  

        String method = invocation.getProxy().getMethod();  

        // ValidationInterceptor   

        boolean applyMethod = MethodFilterInterceptorUtil.applyMethod(excludeMethods, includeMethods, method);  

        if (log.isDebugEnabled()) {  

            if (!applyMethod) {  

                log.debug("Skipping Interceptor... Method [" + method + "] found in exclude list.");  

            }  

        }  

        return applyMethod;  

    }  

      

    /** 

     * Subclasses must override to implement the interceptor logic. 

     *  

     * @param invocation the action invocation 

     * @return the result of invocation 

     * @throws Exception 

     */  

    protected abstract String doIntercept(ActionInvocation invocation) throws Exception;  

      

}  

public abstract class MethodFilterInterceptor extends AbstractInterceptor {
protected transient Logger log = LoggerFactory.getLogger(getClass());

protected Set<String> excludeMethods = Collections.emptySet();
protected Set<String> includeMethods = Collections.emptySet();

public void setExcludeMethods(String excludeMethods) {
this.excludeMethods = TextParseUtil.commaDelimitedStringToSet(excludeMethods);
}

public Set<String> getExcludeMethodsSet() {
return excludeMethods;
}

public void setIncludeMethods(String includeMethods) {
this.includeMethods = TextParseUtil.commaDelimitedStringToSet(includeMethods);
}

public Set<String> getIncludeMethodsSet() {
return includeMethods;
}

@Override
public String intercept(ActionInvocation invocation) throws Exception {
if (applyInterceptor(invocation)) {
return doIntercept(invocation);
}
return invocation.invoke();
}

protected boolean applyInterceptor(ActionInvocation invocation) {
String method = invocation.getProxy().getMethod();
// ValidationInterceptor
boolean applyMethod = MethodFilterInterceptorUtil.applyMethod(excludeMethods, includeMethods, method);
if (log.isDebugEnabled()) {
if (!applyMethod) {
log.debug("Skipping Interceptor... Method [" + method + "] found in exclude list.");
}
}
return applyMethod;
}

/**
* Subclasses must override to implement the interceptor logic.
*
* @param invocation the action invocation
* @return the result of invocation
* @throws Exception
*/
protected abstract String doIntercept(ActionInvocation invocation) throws Exception;

}

只需要实现该类中的

protected abstract String doIntercept(ActionInvocation invocation) throws Exception

即可。

 

 

样例代码：

 

  

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;  

import com.opensymphony.xwork2.interceptor.MethodFilterInterceptor;  

  

public class LoginInterceptor extends MethodFilterInterceptor{  

  

    private static final long serialVersionUID = 1L;  

  

    protected String doIntercept(ActionInvocation action) throws Exception {  

        Map<String, Object> session = ActionContext.getContext().getSession();  

        String user = (String)session.get("user");  

        if(user != null && !"".equals(user)){  

            return action.invoke();  

        }else{  

            session.put("error", "your user or pwd is error, please login again...");  

            return Action.LOGIN;  

        }  

  

    }  

  

}  

package cua.survey.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;
import com.opensymphony.xwork2.interceptor.MethodFilterInterceptor;

public class LoginInterceptor extends MethodFilterInterceptor{

private static final long serialVersionUID = 1L;

protected String doIntercept(ActionInvocation action) throws Exception {
Map<String, Object> session = ActionContext.getContext().getSession();
String user = (String)session.get("user");
if(user != null && !"".equals(user)){
return action.invoke();
}else{
session.put("error", "your user or pwd is error, please login again...");
return Action.LOGIN;
}

}

}

实现之后拦截器属性excludeMethods、includeMethods就可以起到作用了