Struts2 2.18 的 interceptor

首先定义我们自己的Interceptor

package
 com.web.interceptor;

import
 javax.servlet.http.HttpServletRequest;
import
 org.apache.struts2.StrutsStatics;
import
 org.apache.struts2.convention.annotation.ParentPackage;

import
 com.common.utils.StringUtil;
import
 com.opensymphony.xwork2.ActionContext;
import
 com.opensymphony.xwork2.ActionInvocation;
import
 com.opensymphony.xwork2.interceptor.AbstractInterceptor;
import
 com.opensymphony.xwork2.util.ValueStack;
import
 com.web.action.Constants;

@ParentPackage
(value=
"struts-default"
)
public
 
class
 LoginInterceptor 
extends
 AbstractInterceptor
{
    /**
     *
     */
    private
 
static
 
final
 
long
 serialVersionUID = 1L;

    public
 
static
 
final
 String USER_SESSION_KEY=
"wallet.session.user"
;

    public
 
void
 init()
    {}

    @SuppressWarnings
(
"unchecked"
)
    @Override
    public
 String intercept(ActionInvocation invocation) 
throws
 Exception
    {
        ActionContext actionContext = invocation.getInvocationContext();
        HttpServletRequest request = (HttpServletRequest) actionContext.get(StrutsStatics.HTTP_REQUEST);

        String uri = request.getRequestURI();
        if
(uri.indexOf(
"index.action"
)>-
1
)
        {
            return
 Constants.INPUT;
        }
        else
 
if
(uri.indexOf(
"login.action"
)>-
1
)
        {
            ValueStack vt = actionContext.getValueStack();
            java.util.Map<String, Object> mp = vt.getContext();

            java.util.Map<String, Object> paraMap = (java.util.Map<String,Object>)mp.get(ActionContext.PARAMETERS);
            String[] name = (String[])paraMap.get("user.name"
);

            //String name = (String)vt.findValue("user.name");
            if
(name!=
null
 && name.length>
0
 && !StringUtil.hasContent(name[
0
]))
            {
                vt.set("fielderror"
, 
"必须输入用户名!"
);
                return
 Constants.INPUT;
            }
            else
 
return
 invocation.invoke();
        }
        else
            return
 invocation.invoke();
    }

    public
 
void
 destroy()
    {}
}

package com.web.interceptor;

import javax.servlet.http.HttpServletRequest;
import org.apache.struts2.StrutsStatics;
import org.apache.struts2.convention.annotation.ParentPackage;

import com.common.utils.StringUtil;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.interceptor.AbstractInterceptor;
import com.opensymphony.xwork2.util.ValueStack;
import com.web.action.Constants;

@ParentPackage(value="struts-default")
public class LoginInterceptor extends AbstractInterceptor
{
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;

	public static final String USER_SESSION_KEY="wallet.session.user";
	
	public void init()
	{}
	
	@SuppressWarnings("unchecked")
	@Override
	public String intercept(ActionInvocation invocation) throws Exception
	{ 
		ActionContext actionContext = invocation.getInvocationContext();
		HttpServletRequest request = (HttpServletRequest) actionContext.get(StrutsStatics.HTTP_REQUEST);

		String uri = request.getRequestURI();
		if(uri.indexOf("index.action")>-1)
		{
			return Constants.INPUT; 
		}
		else if(uri.indexOf("login.action")>-1)
		{
			ValueStack vt = actionContext.getValueStack();
			java.util.Map<String, Object> mp = vt.getContext();
			
			java.util.Map<String, Object> paraMap = (java.util.Map<String,Object>)mp.get(ActionContext.PARAMETERS);
			String[] name = (String[])paraMap.get("user.name");
		 
			//String name = (String)vt.findValue("user.name");
			if(name!=null && name.length>0 && !StringUtil.hasContent(name[0]))
			{
				vt.set("fielderror", "必须输入用户名!");
				return Constants.INPUT;
			}
			else return invocation.invoke();
		}
		else
			return invocation.invoke();
	}

	public void destroy()
	{}
}

将其注册到struts中，修改struts2.xml文件增加如下内容：

<
package
 name=
"struts-interceptor"
 
extends
=
"struts-default"
>
        <interceptors>
            <interceptor name="loginInterceptor"
 
class
=
"com.web.interceptor.LoginInterceptor"
/>
        </interceptors>
    </package
>

<package name="struts-interceptor" extends="struts-default"> 
		<interceptors> 
		    <interceptor name="loginInterceptor" class="com.web.interceptor.LoginInterceptor"/>
		</interceptors> 
	</package> 

这样我们自己定义的Interceptor已经设置完成，如果想使用则可以用annotation指定。如

@InterceptorRefs
({
  @InterceptorRef
(
"loginInterceptor"
),
  @InterceptorRef
(
"defaultStack"
)
})
@ParentPackage
(value=
"struts-interceptor"
)
@Namespace
(value=
"/application"
)
@Result
(name=
"input"
,location=
"/application/login.jsp"
)
public
 
class
 LoginAction 
extends
 BaseAction
{
    private
 
static
 
final
 
long
 serialVersionUID = 1L;
}

@InterceptorRefs({
  @InterceptorRef("loginInterceptor"),
  @InterceptorRef("defaultStack")
})
@ParentPackage(value="struts-interceptor")  
@Namespace(value="/application")  
@Result(name="input",location="/application/login.jsp")
public class LoginAction extends BaseAction
{
	private static final long serialVersionUID = 1L;
}	

我们在LoginAction里使用了刚刚自定义的Interceptor。

官网教程提供的解决方案：

引用

If you get errors like "Unable to find interceptor class referenced by ref-name XYZ". This means that the package where Convention is placing your actions, does not extend the package where the interceptor is defined. To fix this problem either 1)Use @ParentPackage annotation(or struts.convention.default.parent.package) passing the name of the package that defines the interceptor, or 2) Create a package in XML that extends the package that defines the interceptor, and use @ParentPackage(or struts.convention.default.parent.package) to point to it.