问题描述

我在我的 Web 应用程序中使用 Struts 2.我编写代码将用户会话检查到拦截器中，但是当我返回 net.sf.json.JSONObject 作为响应时，它会重置响应对象并将 null 设置为对象.请检查我的代码.

导入 net.sf.json.JSONObject;导入 com.opensymphony.xwork2.interceptor.Interceptor；公共类 AuthorizationInterceptor 实现拦截器 {JSONObject 响应 = 新 JSONObject();公共字符串拦截(ActionInvocation 调用){尝试 {映射会话 = invocation.getInvocationContext().getSession();if (session.get("userId") == null) {response.put("errorCode", "SESSION_OUT");返回 ActionSupport.ERROR；} 别的 {System.out.println("找到会话");对象动作 = invocation.getAction();返回调用.invoke();}} 捕捉(异常 e){返回 ActionSupport.ERROR；}}公共 JSONObject getResponse() {返回响应；}公共无效 setResponse(JSONObject 响应){this.response = 响应；}

}

如何获取 JSON 对象作为拦截器的响应.请帮我解决这个问题.

您的代码中有多个错误.

• 响应是 HttpServletResponse，你应该不要将该名称赋予 JSONObject.
• 拦截器不是线程安全的，这意味着您应该在方法内定义 JSONObject，以防止多个用户同时更新它，一个在另一个之上
• 您应该按照 JSON 插件中的说明使用 statusCode 或 errorCode 文档，将其配置为您返回的错误结果:

使用 statusCode 设置响应的状态:

<result name="error" type="json"><param name="statusCode">304</param></结果>

<块引用>

和 errorCode 发送错误(服务器可能最终向客户端发送不是序列化 JSON 的内容):

 <result name="error" type="json"><param name="errorCode">404</param></结果>

然后在 AJAX 回调函数中读取它的客户端.

I am using Struts 2 in my web application. I write code to check user session into interceptor but while I am returning net.sf.json.JSONObject as response, its reset the response object and set null to the object. Please check my code.

import net.sf.json.JSONObject;
import com.opensymphony.xwork2.interceptor.Interceptor;

public class AuthorizationInterceptor implements Interceptor {

JSONObject response = new JSONObject();

public String intercept(ActionInvocation invocation) {
 try { 
      Map session = invocation.getInvocationContext().getSession();
        if (session.get("userId") == null) {
           response.put("errorCode", "SESSION_OUT");                
            return ActionSupport.ERROR;
        } else {
            System.out.println("Session found");
            Object action = invocation.getAction();
            return invocation.invoke();
        }
    } catch (Exception e) {
        return ActionSupport.ERROR;
    }
}

public JSONObject getResponse() {
    return response;
}

public void setResponse(JSONObject response) {
    this.response = response;
}

}

How can I get the JSON Object as response from interceptor. Please help me to resolve this issue.

There are mutliple errors in your code.

• Response is HttpServletResponse, you should not give that name to a JSONObject.
• Interceptors are NOT THREAD-SAFE, that means that you should define the JSONObject inside the method, to prevent multiple users to update it concurrently, one over the other
• You should use statusCode or errorCode as described in the JSON plugin documentation, by configuring it as the Error result you are returning:

Use statusCode to set the status of the response:

<result name="error" type="json">
  <param name="statusCode">304</param>
</result>

And errorCode to send an error(the server might end up sending something to the client which is not the serialized JSON):

 <result name="error" type="json">
  <param name="errorCode">404</param>
</result>

and then read it client-side in the AJAX callback function.