GWT RequestBuilder-跨站点请求

Question

我正在尝试使用“
GWT请求”构建器发出“跨站点请求”，但我无法使其正常工作。如您所见，这是一个GWT示例项目的大部分内容，我已经浏览了https://developers.google.com/web-
toolkit/doc/latest/tutorial/Xsite
。但是我仍然缺少一些东西。

我在这里发布代码。我在想什么..？

package com.gwt.reqbuilder.client;

import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.http.client.Request;
import com.google.gwt.http.client.RequestBuilder;
import com.google.gwt.http.client.RequestCallback;
import com.google.gwt.http.client.RequestException;
import com.google.gwt.http.client.Response;
import com.google.gwt.http.client.URL;
import com.google.gwt.user.client.Window;

public class GWTRequestBuilder implements EntryPoint
{
    private static final String JSON_URL = "http://localhost:8000/?q=ABC&callback=callback125";
    public void onModuleLoad()
    {
        GWTPOSTHTTP();
    }

    public void GWTPOSTHTTP()
    {
        String postUrl="http://localhost:8000";
        String requestData="q=ABC&callback=callback125";
        RequestBuilder builder = new RequestBuilder(RequestBuilder.POST, postUrl);
        try {
            builder.sendRequest(requestData.toString(), new RequestCallback() 
            {
                public void onError(Request request, Throwable e) 
                {
                    Window.alert(e.getMessage());
                }
                public void onResponseReceived(Request request, Response response)
            {
                    if (200 == response.getStatusCode())
                    {
                        Window.alert(response.getText());
                    } else {
                        Window.alert("Received HTTP status code other than 200 : "+ response.getStatusText());
                    }
            }
            });
        } catch (RequestException e) {
            // Couldn't connect to server
        Window.alert(e.getMessage());
        }
    }
}

Answer 1

实际上，如果可以在Servlet Response Header中进行设置，则可以从GWT RequestBuilder发出跨站点请求

Response.setHeader("Access-Control-Allow-Origin","http://myhttpserver");

工作正常，如果有人需要GWT项目和Python Servlet，请告诉我，我可以上传文件。

GWT Client Code : https://github.com/manikandaraj/MLabs/tree/master/GWT/GWTClient