RequestBuilder处理rss

创建一个测试数据rss.xml

<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0">
<channel>
	<title>焦点新闻</title>
	<item>
		<title>百度今晨被黑客攻击</title>
		<link>http://www.iteye.com/news/12883</link>
	</item>
	<item>
		<title>Android 2.1 SDK 发布</title>
		<link>http://www.iteye.com/news/12897</link>
	</item>
	<item>
		<title>震撼人心的新科技 - Sixth Sense</title>
		<link>http://www.iteye.com/news/12856</link>
	</item>
	<item>
		<title>IBM内部秘密研发翻译软件挑战Google</title>
		<link>http://www.iteye.com/news/12828</link>
	</item>
</channel>
</rss>

package com.single.test.client;

import com.extjs.gxt.ui.client.event.DragEvent;
import com.extjs.gxt.ui.client.event.DragListener;
import com.extjs.gxt.ui.client.fx.Draggable;
import com.extjs.gxt.ui.client.widget.ContentPanel;
import com.extjs.gxt.ui.client.widget.ModalPanel;
import com.extjs.gxt.ui.client.widget.Popup;
import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.core.client.GWT;
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.RequestTimeoutException;
import com.google.gwt.http.client.Response;
import com.google.gwt.user.client.Window;
import com.google.gwt.user.client.ui.Composite;
import com.google.gwt.user.client.ui.HTML;
import com.google.gwt.user.client.ui.NamedFrame;
import com.google.gwt.user.client.ui.RootPanel;
import com.google.gwt.user.client.ui.VerticalPanel;
import com.google.gwt.user.client.ui.VerticalSplitPanel;
import com.google.gwt.xml.client.Document;
import com.google.gwt.xml.client.Node;
import com.google.gwt.xml.client.NodeList;
import com.google.gwt.xml.client.XMLParser;

public class Test implements EntryPoint {

	
	public void onModuleLoad() {
		try {
			//创建请求
			RequestBuilder builder=new RequestBuilder(RequestBuilder.GET, GWT.getHostPageBaseURL()+"rss.xml");
			
			builder.setTimeoutMillis(5000);
			builder.sendRequest(null, new RssHandler());
		} catch (RequestException e) {
			e.printStackTrace();
		}
		
	}
	/**
	 * 请求返回后的处理
	 */
	class RssHandler implements RequestCallback{
		@Override
		public void onError(Request request, Throwable exception) {
			if(exception instanceof RequestTimeoutException){
				Window.alert("请求超时");
			}else{
				Window.alert("发生异常");
			}
		}
		@Override
		public void onResponseReceived(Request request, Response response) {
			//如果返回异常(code!=200)
			if(response.getStatusCode()!=Response.SC_OK){
				Window.alert("发生异常");
				return;
			}
			//创建RSS面板
			RssContainer rssContainer=new RssContainer(response);
			//添加到页面
			RootPanel.get().add(rssContainer);
		}
		
	}
	/**
	 * Rss内容显示面板
	 */
	class RssContainer extends Composite{
		VerticalSplitPanel vsPanel;
		VerticalPanel vPanel;
		NamedFrame contentFrame;
		HTML html;
		String title;
		String url;
		public RssContainer(Response response){
			vsPanel=new VerticalSplitPanel();
			vPanel=new VerticalPanel();
			contentFrame=new NamedFrame("content");
			
			Document doc=XMLParser.parse(response.getText());
			XMLParser.removeWhitespace(doc);
			NodeList elements=doc.getElementsByTagName("item");
			//遍历item,获取标题与url地址
			for(int i=0;i<elements.getLength()&&i<10;i++){
				Node element=elements.item(i);
				Node titleElement=element.getFirstChild();
				Node urlElement=titleElement.getNextSibling();
				
				title=titleElement.getFirstChild().getNodeValue();
				url=urlElement.getFirstChild().getNodeValue();
				html=new HTML("<a href=\""+url+"\" target=content>"+(i+1)+"."+title+"</a>");
				vPanel.add(html);
			}
			
			vPanel.add(contentFrame);
			vPanel.setStyleName("demo-VerticalPanel");
			
			contentFrame.setSize("400px", "500px");
			vsPanel.setTopWidget(vPanel);
			vsPanel.setBottomWidget(contentFrame);
			vsPanel.setSize("400px", "600px");
			vsPanel.setSplitPosition("100px");
			
			initWidget(vsPanel);
		}
	}
}

评论

1 楼 java-007 2010-03-03