HalfDuplexEndPoint.java

package angularBeans.remote;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.Serializable;

import javax.enterprise.event.Event;
import javax.inject.Inject;
import javax.servlet.AsyncContext;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import com.google.gson.JsonObject;

import angularBeans.context.BeanLocator;
import angularBeans.context.NGSessionScopeContext;
import angularBeans.util.AngularBeansUtils;
import angularBeans.util.CommonUtils;
import angularBeans.util.Constants;

/**
 * The HalfDuplexEndPoint servlet is a standard HTTP protocol endpoint
 * 
 * @author Bessem Hmidi
 *
 */
@SuppressWarnings("serial")
@WebServlet(asyncSupported = true, urlPatterns = Constants.URL_PATTERNS)
public class HalfDuplexEndPoint extends HttpServlet implements Serializable {
	
	public static final String URL_PATTERNS = "/http/invoke/*";

	@Inject
	InvocationHandler remoteInvoker;

	@Inject
	BeanLocator locator;

	@Inject
	AngularBeansUtils util;

	@Inject
	HttpSession session;

	@Inject
	@DataReceivedEvent
	private Event<DataReceived> receiveEvents;

	@Override
	protected void doPost(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		process(req, resp);
	}

	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		process(req, resp);
	}

	@Override
	protected void doPut(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		process(req, resp);
	}

	@Override
	protected void doDelete(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		process(req, resp);
	}

	
	@Override
	protected void doOptions(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		process(request, response);
		
	}
	private void process(HttpServletRequest request, HttpServletResponse resp) {

		AsyncContext asyncContext=request.startAsync();
		
		resp.setCharacterEncoding("UTF-8");

		if(request.getRequestURL().toString().endsWith("/CORS")){
			resp.addHeader("Access-Control-Allow-Origin", "*");
			resp.addHeader("Access-Control-Allow-Methods", "POST, GET, PUT, DELETE");
			resp.addHeader("Access-Control-Allow-Headers","Origin, X-Requested-With, Content-Type, Accept");
		}
		
		 // Just ACCEPT and REPLY OK if OPTIONS
	    if ( request.getMethod().equals("OPTIONS") ) {
	        resp.setStatus(HttpServletResponse.SC_OK);

	    }
		
		String fullPath = request.getRequestURI();
		fullPath = (fullPath.substring(fullPath.indexOf("/service/") + 9));

		String parts[] = fullPath.split("/");

		String beanName = parts[0];
		String method = parts[1];

		String params = request.getParameter("params");

		if (request.getMethod().equals("POST")) {
			try {
				StringBuilder buffer = new StringBuilder();
				BufferedReader reader;

				reader = request.getReader();

				String line;

				while ((line = reader.readLine()) != null) {
					buffer.append(line);
				}

				params = buffer.toString();
			
			} catch (Exception e) {
				// TODO: handle exception
			}
		}

		JsonObject paramsObj = CommonUtils.parse(params).getAsJsonObject();

		String UID = session.getId();// (paramsObj.get("sessionUID")).getAsString();

		NGSessionScopeContext.setCurrentContext(UID);

		
		
		receiveEvents.fire(new HalfDuplexDataReceivedEvent(paramsObj));

		Object result = remoteInvoker.invoke(locator.lookup(beanName, UID),
				method, paramsObj, UID,request);



		try {
			PrintWriter writer=asyncContext.getResponse().getWriter();
			writer.write( util.getJson(result));
			writer.flush();
			asyncContext.complete();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

}