struts2不能通过ONGL方式取出request中的Atrribute

请看下面一个很简单的Action

package com.ahgw.main.action;

import org.springframework.stereotype.Controller;

/**
 * Created with IntelliJ IDEA.
 * User: HYY
 * Date: 13-11-19
 * Time: 下午7:08
 * To change this template use File | Settings | File Templates.
 */
@Controller
public class Test2Action {
    private String hyy;

    public String execute() {
        System.out.println("hyy = " + hyy);
        return "success";
    }

    public String getHyy() {
        return hyy;
    }

    public void setHyy(String hyy) {
        this.hyy = hyy;
    }
}

一般来说，如果request有hyy这个parameter，那么可以获取该值。然后如果request中仅有key为hyy的Atrribute，那么这一段代码是获取不了该值的。

请继续看：

public class TestInterceptor extends AbstractInterceptor {

    @Override
    public String intercept(ActionInvocation actionInvocation) throws Exception {
        HttpServletRequest request = (HttpServletRequest) actionInvocation.getInvocationContext().get(ServletActionContext.HTTP_REQUEST);
        request.setAttribute("hyy", "heyiyong");
        System.out.println("经过测试拦截器");
        return actionInvocation.invoke();
    }
}

        <interceptors>
            <interceptor name="testInterceptor" class="com.ahgw.admin.interceptor.TestInterceptor"></interceptor>
        </interceptors>

        <action name="test2Action" class="test2Action">
            <interceptor-ref name="testInterceptor"></interceptor-ref>
            <result>/test.jsp</result>
        </action>

了解清楚后，在浏览器输入/test2Action.do发现输出如下：

经过测试拦截器
hyy = null

总结：在struts2的action中，通过OGNL方式不能获取atrribute而只能获取到parameter的值。