Java tutorial
package cache.reverseproxy; /* * ==================================================================== * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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. * ==================================================================== * * This software consists of voluntary contributions made by many * individuals on behalf of the Apache Software Foundation. For more * information on the Apache Software Foundation, please see * <http://www.apache.org/>. * */ import java.io.IOException; import java.io.InterruptedIOException; import java.net.ServerSocket; import java.net.Socket; import javax.net.SocketFactory; import javax.net.ssl.SSLSocket; import javax.net.ssl.SSLSocketFactory; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.http.ConnectionClosedException; import org.apache.http.ConnectionReuseStrategy; import org.apache.http.Header; import org.apache.http.HttpClientConnection; import org.apache.http.HttpEntity; import org.apache.http.HttpEntityEnclosingRequest; import org.apache.http.HttpException; import org.apache.http.HttpRequest; import org.apache.http.HttpRequestInterceptor; import org.apache.http.HttpResponse; import org.apache.http.HttpResponseInterceptor; import org.apache.http.HttpServerConnection; import org.apache.http.RequestLine; import org.apache.http.entity.BufferedHttpEntity; import org.apache.http.impl.DefaultBHttpClientConnection; import org.apache.http.impl.DefaultBHttpServerConnection; import org.apache.http.impl.DefaultConnectionReuseStrategy; import org.apache.http.message.BasicHttpEntityEnclosingRequest; import org.apache.http.message.BasicHttpRequest; import org.apache.http.protocol.BasicHttpContext; import org.apache.http.protocol.HTTP; import org.apache.http.protocol.HttpContext; import org.apache.http.protocol.HttpProcessor; import org.apache.http.protocol.HttpRequestExecutor; import org.apache.http.protocol.HttpRequestHandler; import org.apache.http.protocol.HttpService; import org.apache.http.protocol.ImmutableHttpProcessor; import org.apache.http.protocol.RequestConnControl; import org.apache.http.protocol.RequestContent; import org.apache.http.protocol.RequestExpectContinue; import org.apache.http.protocol.RequestTargetHost; import org.apache.http.protocol.RequestUserAgent; import org.apache.http.protocol.ResponseConnControl; import org.apache.http.protocol.ResponseContent; import org.apache.http.protocol.ResponseDate; import org.apache.http.protocol.ResponseServer; import org.apache.http.protocol.UriHttpRequestHandlerMapper; import org.apache.http.util.EntityUtils; /** * @Author: Sreedhar Meduru * Elemental HTTP/1.1 reverse proxy. */ public class CacheableServicesReverseProxy { private static final Log log = LogFactory.getLog(CacheableServicesReverseProxy.class); private static final String HTTP_IN_CONN = "http.proxy.in-conn"; private static final String HTTP_OUT_CONN = "http.proxy.out-conn"; private static final String HTTP_CONN_KEEPALIVE = "http.proxy.conn-keepalive"; public static void main(final String[] args) throws Exception { int port = 8888; if (args.length > 0) { try { port = Integer.parseInt(args[0]); } catch (Exception e) { System.err.println("->Invalid Port!!"); } } final Thread t = new RequestListenerThread(port); t.setDaemon(false); t.start(); } static class ProxyHandler implements HttpRequestHandler { final int bufsize = 8 * 1024; private final HttpProcessor httpproc; private final HttpRequestExecutor httpexecutor; private final ConnectionReuseStrategy connStrategy; public ProxyHandler(final HttpProcessor httpproc, final HttpRequestExecutor httpexecutor) { super(); this.httpproc = httpproc; this.httpexecutor = httpexecutor; this.connStrategy = DefaultConnectionReuseStrategy.INSTANCE; } public void handle(final HttpRequest request, final HttpResponse response, final HttpContext context) throws HttpException, IOException { try { ProxyConfig.URIConfig uriConfig = ProxyConfig.getReverseProxyUrl(request.getRequestLine().getUri()); //request.addHeader("Access-Control-Allow-Origin", "*"); CacheableRequest cacheableRequest = RequestHashCodeStrategy.generateHashCode(request, uriConfig); String requestFileName = cacheableRequest.getRequestFileName(); String responseFileName = cacheableRequest.getResponseFileName(); String hashCodeFileName = cacheableRequest.getHashCodeFileName(); boolean isSoap = cacheableRequest.isSoap(); if (log.isDebugEnabled()) { /*log.debug("--------------------------------------------------------------> Original Request Begin"); log.debug(cacheableRequest.toString()); log.debug("--------------------------------------------------------------> Original Request End"); log.debug("--------------------------------------------------------------> HashCode Request String Begin"); log.debug(cacheableRequest.getHashCodeString()); log.debug("HashCode:" + cacheableRequest.getHashCode()); log.debug("--------------------------------------------------------------> HashCode Request String End"); */ } CachedResponseParser.saveFile(hashCodeFileName, cacheableRequest.getHashCodeString(), isSoap); HttpResponse targetResponse = CachedResponseParser.getResponseFromParsedFile(responseFileName, isSoap); boolean isFileSave = false; StringBuilder logStr = new StringBuilder(); if (targetResponse == null) { logStr.append("==> Hitting Back End Server..."); CachedResponseParser.saveFile(requestFileName, cacheableRequest.toString(), isSoap); // Set up outgoing HTTP connection //final Socket outsocket = new Socket(this.target.getHostName(), this.target.getPort()); final Socket outsocket; if (uriConfig.isSecure()) outsocket = createSecureSocket(uriConfig.getServer(), uriConfig.getPort()); else outsocket = createInsecureSocket(uriConfig.getServer(), uriConfig.getPort()); final DefaultBHttpClientConnection outconn = new CacheableBHttpClientConnection(bufsize); //context.setAttribute(HTTP_OUT_CONN, outconn); //context.setAttribute(HttpCoreContext.HTTP_CONNECTION, outconn); //context.setAttribute(HttpCoreContext.HTTP_TARGET_HOST, this.target); RequestLine origRequestLine = request.getRequestLine(); BasicHttpRequest basicHttpRequest = null; if (request instanceof HttpEntityEnclosingRequest) { BasicHttpEntityEnclosingRequest enclosingRequest = new BasicHttpEntityEnclosingRequest( origRequestLine.getMethod(), uriConfig.getContext(), origRequestLine.getProtocolVersion()); enclosingRequest.setEntity(((HttpEntityEnclosingRequest) request).getEntity()); basicHttpRequest = enclosingRequest; } else { basicHttpRequest = new BasicHttpRequest(origRequestLine.getMethod(), uriConfig.getContext(), origRequestLine.getProtocolVersion()); } basicHttpRequest.setHeaders(request.getAllHeaders()); basicHttpRequest.setParams(request.getParams()); outconn.bind(outsocket); this.httpexecutor.preProcess(basicHttpRequest, this.httpproc, context); targetResponse = this.httpexecutor.execute(basicHttpRequest, outconn, context); this.httpexecutor.postProcess(response, this.httpproc, context); isFileSave = true; } else { logStr.append("==> Using cache to send the response..."); } logStr.append("[Context:" + request.getRequestLine().getUri()); logStr.append(", SoapAction:" + cacheableRequest.getSoapAction()); //logStr.append(", HashCode:" + cacheableRequest.getHashCode()); logStr.append(", ReqFile:" + requestFileName); logStr.append(", RespFile:" + responseFileName + "]"); StringBuilder sb = new StringBuilder(); sb.append(targetResponse.getStatusLine()).append("\r\n"); boolean isResponseOK = targetResponse.getStatusLine().toString().indexOf(" 200 ") > -1; for (Header header : targetResponse.getAllHeaders()) { sb.append(header.toString()).append("\r\n"); } HttpEntity entity = new BufferedHttpEntity(targetResponse.getEntity()); targetResponse.setEntity(entity); if (entity != null) { byte[] entityContent = EntityUtils.toByteArray(entity); String content = new String(entityContent); sb.append("\r\n"); sb.append(content); } String responseString = sb.toString(); if (isFileSave) { if (isResponseOK) { CachedResponseParser.saveFile(responseFileName, responseString, isSoap); } else { logStr.append("\\n Backend Failure on the above request!"); } } System.out.println(logStr); if (log.isDebugEnabled()) { log.debug("--------------------------------------------------------------> Response Begin"); log.debug(responseString); log.debug("--------------------------------------------------------------> Response End"); } // Remove hop-by-hop headers targetResponse.removeHeaders(HTTP.CONTENT_LEN); targetResponse.removeHeaders(HTTP.TRANSFER_ENCODING); targetResponse.removeHeaders(HTTP.CONN_DIRECTIVE); targetResponse.removeHeaders("Keep-Alive"); targetResponse.removeHeaders("TE"); targetResponse.removeHeaders("Trailers"); targetResponse.removeHeaders("Upgrade"); targetResponse.removeHeaders("Upgrade"); targetResponse.removeHeaders("Transfer-Encoding"); response.setStatusLine(targetResponse.getStatusLine()); response.setHeaders(targetResponse.getAllHeaders()); response.setEntity(targetResponse.getEntity()); final boolean keepalive = this.connStrategy.keepAlive(response, context); context.setAttribute(HTTP_CONN_KEEPALIVE, new Boolean(keepalive)); } catch (Exception e) { e.printStackTrace(); throw new IOException(e.getMessage()); } } } static class RequestListenerThread extends Thread { private final ServerSocket serversocket; private final HttpService httpService; public RequestListenerThread(final int port) throws IOException { this.serversocket = new ServerSocket(port); System.out.println("Running Server on the port:" + port); // Set up HTTP protocol processor for incoming connections final HttpProcessor inhttpproc = new ImmutableHttpProcessor(new HttpRequestInterceptor[] { new RequestContent(true), new RequestTargetHost(), new RequestConnControl(), new RequestUserAgent("Test/1.1"), new RequestExpectContinue(false) }); // Set up HTTP protocol processor for outgoing connections final HttpProcessor outhttpproc = new ImmutableHttpProcessor( new HttpResponseInterceptor[] { new ResponseDate(), new ResponseServer("Test/1.1"), new ResponseContent(true), new ResponseConnControl() }); // Set up outgoing request executor final HttpRequestExecutor httpexecutor = new HttpRequestExecutor(); // Set up incoming request handler final UriHttpRequestHandlerMapper reqistry = new UriHttpRequestHandlerMapper(); reqistry.register("*", new ProxyHandler(outhttpproc, httpexecutor)); // Set up the HTTP service this.httpService = new HttpService(inhttpproc, reqistry); } @Override public void run() { System.out.println("Listening on port " + this.serversocket.getLocalPort()); while (!Thread.interrupted()) { try { final int bufsize = 8 * 1024; // Set up incoming HTTP connection final Socket insocket = this.serversocket.accept(); final DefaultBHttpServerConnection inconn = new DefaultBHttpServerConnection(bufsize); //System.out.println("Incoming connection from " + insocket.getInetAddress()); inconn.bind(insocket); // Start worker thread final Thread t = new ProxyThread(this.httpService, inconn); t.setDaemon(true); t.start(); } catch (final InterruptedIOException ex) { break; } catch (final IOException e) { System.err.println("I/O error initialising connection thread: " + e.getMessage()); break; } } } } static class ProxyThread extends Thread { private final HttpService httpservice; private final HttpServerConnection inconn; private HttpClientConnection outconn; public ProxyThread(final HttpService httpservice, final HttpServerConnection inconn) { super(); this.httpservice = httpservice; this.inconn = inconn; } @Override public void run() { //System.out.println("New connection thread"); final HttpContext context = new BasicHttpContext(null); // Bind connection objects to the execution context context.setAttribute(HTTP_IN_CONN, this.inconn); //context.setAttribute(HTTP_OUT_CONN, this.outconn); try { while (!Thread.interrupted()) { if (this.outconn == null) { this.outconn = (HttpClientConnection) context.getAttribute(HTTP_OUT_CONN); } if (!this.inconn.isOpen() && this.outconn != null) { this.outconn.close(); break; } this.httpservice.handleRequest(this.inconn, context); final Boolean keepalive = (Boolean) context.getAttribute(HTTP_CONN_KEEPALIVE); if (!Boolean.TRUE.equals(keepalive)) { if (this.outconn != null) this.outconn.close(); this.inconn.close(); break; } } } catch (final ConnectionClosedException ex) { //System.err.println("Client closed connection"); } catch (final IOException ex) { System.err.println("I/O error: " + ex.getMessage()); } catch (final HttpException ex) { System.err.println("Unrecoverable HTTP protocol violation: " + ex.getMessage()); } finally { try { this.inconn.shutdown(); } catch (final IOException ignore) { } try { if (this.outconn != null) this.outconn.shutdown(); } catch (final IOException ignore) { } } } } public static Socket createSecureSocket(String host, int port) throws IOException { SSLSocketFactory sslFactory = (SSLSocketFactory) SSLSocketFactory.getDefault(); SSLSocket newSocket = (SSLSocket) sslFactory.createSocket(host, port); newSocket.setUseClientMode(true); newSocket.startHandshake(); return newSocket; } public static Socket createInsecureSocket(String host, int port) throws IOException { Socket newSocket = (Socket) SocketFactory.getDefault().createSocket(host, port); return newSocket; } }