buffaloserviceservlet.java

AJAX的一个好东西哦,国人的一个AJAX的实现不错的东西

/*
 * Copyright 2002-2004 the original author or authors.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * 
 * $Id: BuffaloServiceServlet.java 43 2005-12-12 01:24:50Z michael $
 */ 

package net.buffalo.server;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.Properties;

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.caucho.burlap.io.BurlapInput;
import com.caucho.burlap.io.BurlapOutput;
import com.caucho.burlap.server.BurlapSkeleton;

/**
 * Buffalo Service Servlet, the central servlet for the 
 * Buffalo Service.
 * 
 * @author michael
 * @version 1.0
 * @deprecated
 */
public class BuffaloServiceServlet extends HttpServlet {
    
	private static final long serialVersionUID = 2058268530956658665L;

	private static final String BUFFALO_SERVICE_KEY = 
        			"net.buffalo.service.BUFFALO_SERVICE";
    
	private Object _service;

	private BurlapSkeleton _skeleton;
	
	private boolean isDebug;
	
	public String getServletInfo() {
		return "Buffalo Service Servlet";
	}

	/**
	 * Initialize the service, including the service object.
	 */
	public void init(ServletConfig config) throws ServletException {
		super.init(config);
		isDebug = config.getInitParameter("debug").equals("true");
	}

	public synchronized void service(ServletRequest request, ServletResponse response)
			throws IOException, ServletException {
		HttpServletRequest req = (HttpServletRequest) request;
		HttpServletResponse res = (HttpServletResponse) response;

		if (!req.getMethod().equals("POST")) {
			res.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR,
					"Buffalo Requires POST");
			PrintWriter out = res.getWriter();

			res.setContentType("text/html");
			out.println("<h1>Buffalo Requires POST</h1>");
			
			return;
		}

		String serviceName = request.getParameter(Buffalo.SERVICE_NAME_ID);
		//System.out.println(serviceName);
		String serviceClazz = getServiceClass(serviceName);

		try {
			_service = Class.forName(serviceClazz).newInstance();
			
			if (_service instanceof BuffaloService) {
				//System.out.println(_service);  
				((BuffaloService) _service).init(getServletContext(), request);
			}
			_skeleton = new BurlapSkeleton(_service);
		} catch (Exception ex) {
			throw new ServletException(ex);
		}
		InputStream is = request.getInputStream();
		OutputStream os = response.getOutputStream();

		BurlapInput in = new BurlapInput(is);
		BurlapOutput out = new BurlapOutput(os) {
			public void startReply() throws IOException {
				print("<?xml version=\"1.0\" encoding=\"utf-8\"?><burlap:reply xmlns:burlap=\"http://www.amowa.net/buffalo/\">");
			}
		};

		try {
			_skeleton.invoke(in, out);
		} catch (Throwable e) {
			throw new ServletException(e);
		}
	}

	/**
	 * Get the service class name from the buffalo config file by the 
	 * service name. 
	 * 
	 * @param serviceName the service name
	 * @return the service class name
	 *  
	 * @throws IOException
	 */
	private String getServiceClass(String serviceName) throws IOException {
	    ServiceRepository repo = null;
	    if (getServletContext().getAttribute(BUFFALO_SERVICE_KEY) == null) {
	        Properties prop = new Properties();
			InputStream in = getClass().getResourceAsStream("/buffalo-service.properties");
			prop.load(in);
			repo = BuffaloUtils.populateRepository(prop);
			getServletContext().setAttribute(BUFFALO_SERVICE_KEY, repo);
	    } else {
	        repo = (ServiceRepository) (getServletContext().getAttribute(BUFFALO_SERVICE_KEY));
	    }
		
		return repo.getService(serviceName);
	}
}