messageposter.java

一个以tomcat作为服务器的C/S架构的聊天系统

package com.cxz.httpchat.util;

import java.io.IOException;
import java.util.Properties;
import java.util.Set;

import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpException;
import org.apache.commons.httpclient.methods.PostMethod;
import org.apache.commons.httpclient.methods.RequestEntity;
import org.apache.commons.httpclient.methods.StringRequestEntity;

import com.thoughtworks.xstream.XStream;
import com.thoughtworks.xstream.io.StreamException;

/**
 * 
 * @author CXZ
 * 
 * @param <REQ_OBJ>
 * @param <RESP_OBJ>
 * 
 * @version 2.0 of MessagePoster
 * This Class is used by client to send a post message
 */
public class MessagePoster<REQ_OBJ, RESP_OBJ> {
	private String url = "http://localhost:8080/HttpChat/Server";

	private String propLoc = "com/cxz/httpchat/util/class.properties";

	// The XStream instance is thread-safe.
	public XStream xstream = null;

	public MessagePoster() {
		initXStream();
	}

	public void setUrl(String url) {
		this.url = url;
	}

	private void initXStream() {
		xstream = new XStream();
		Properties properties = new Properties();
		try {
			properties.load(MessagePoster.class.getClassLoader()
					.getResourceAsStream(propLoc));
			Set keys = properties.keySet();
			for (Object key : keys) {
				xstream.alias((String) key, Class.forName((String) properties
						.get(key)));
			}
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

	public RESP_OBJ postXML(REQ_OBJ requestObj) throws HttpException,
			IOException {
		RESP_OBJ responseObj = null;
		PostMethod method = null;
		try {
			String xml = xstream.toXML(requestObj);
			HttpClient client = new HttpClient();
			method = new PostMethod(url);
			RequestEntity entity;
			entity = new StringRequestEntity(xml, "text/xml", "utf-8");
			method.setRequestEntity(entity);
			client.executeMethod(method);
			responseObj = (RESP_OBJ) xstream.fromXML(method
					.getResponseBodyAsStream());
		} catch(StreamException e){
			e.printStackTrace();
		} finally {
			method.releaseConnection();
		}
		return responseObj;
	}

	public static void main(String[] args) {
//		try {
//			UploadRequest upload = new UploadRequest();
//			upload.setUserId(1);
//			upload.setPassword("19841230");
//			upload.setType(AbstractMessage.HEART_BEAT_REQUEST);
//			upload.setFrom("joanna");
//			upload.setContent("Hi");
//			upload.setDate(new Date(System.currentTimeMillis()));
//			upload.setType(AbstractMessage.UPLOAD_REQUEST);
//			upload.setTo(12);
//			new MessagePoster<UploadRequest, UploadResponse>().postXML(upload);
//		} catch (HttpException e) {
//			// TODO Auto-generated catch block
//			e.printStackTrace();
//		} catch (IOException e) {
//			// TODO Auto-generated catch block
//			e.printStackTrace();
//		}
	}
}