Java tutorial
/* * Copyright (C) 2007 - 2013 GeoSolutions S.A.S. * http://www.geo-solutions.it * * GPLv3 + Classpath exception * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ package it.geosolutions.httpproxy.service.impl; import it.geosolutions.httpproxy.callback.ProxyCallback; import it.geosolutions.httpproxy.exception.HttpErrorException; import it.geosolutions.httpproxy.service.ProxyConfig; import it.geosolutions.httpproxy.service.ProxyHelper; import it.geosolutions.httpproxy.service.ProxyService; import it.geosolutions.httpproxy.utils.ProxyInfo; import it.geosolutions.httpproxy.utils.ProxyMethodConfig; import it.geosolutions.httpproxy.utils.Utils; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.Serializable; import java.net.URL; import java.util.ArrayList; import java.util.Enumeration; import java.util.List; import java.util.logging.Level; import java.util.logging.Logger; import javax.servlet.ServletException; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.fileupload.FileItem; import org.apache.commons.fileupload.FileUploadException; import org.apache.commons.fileupload.disk.DiskFileItemFactory; import org.apache.commons.fileupload.servlet.ServletFileUpload; import org.apache.commons.httpclient.Header; import org.apache.commons.httpclient.HttpClient; import org.apache.commons.httpclient.HttpException; import org.apache.commons.httpclient.HttpMethod; import org.apache.commons.httpclient.HttpStatus; import org.apache.commons.httpclient.MultiThreadedHttpConnectionManager; import org.apache.commons.httpclient.UsernamePasswordCredentials; import org.apache.commons.httpclient.auth.AuthScope; import org.apache.commons.httpclient.methods.EntityEnclosingMethod; import org.apache.commons.httpclient.methods.InputStreamRequestEntity; import org.apache.commons.httpclient.methods.PostMethod; import org.apache.commons.httpclient.methods.multipart.ByteArrayPartSource; import org.apache.commons.httpclient.methods.multipart.FilePart; import org.apache.commons.httpclient.methods.multipart.MultipartRequestEntity; import org.apache.commons.httpclient.methods.multipart.Part; import org.apache.commons.httpclient.methods.multipart.StringPart; import org.apache.commons.httpclient.params.HttpConnectionManagerParams; /** * HTTPProxy delegated in this service * * @author Alessio Fabiani at alessio.fabiani@geo-solutions.it * @author Tobia Di Pisa at tobia.dipisa@geo-solutions.it * @author Simone Giannecchini, GeoSolutions SAS * @author Alejandro Diaz */ public class ProxyServiceImpl implements ProxyService, Serializable { /** * */ private static final long serialVersionUID = 3318254969779984284L; private final static Logger LOGGER = Logger.getLogger(ProxyServiceImpl.class.toString()); /** * The maximum size for uploaded files in bytes. Default value is 5MB. */ private int maxFileUploadSize = Utils.DEFAULT_MAX_FILE_UPLOAD_SIZE; /** * An Apache commons HTTP client backed by a multithreaded connection manager that allows to reuse connections to the backing server and to limit * the max number of concurrent connections. */ private MultiThreadedHttpConnectionManager connectionManager; /** * An HTTP "user-agent", containing an HTTP state and one or more HTTP connections, to which HTTP methods can be applied. */ private HttpClient httpClient; /** * The proxy configuration. */ private ProxyConfig proxyConfig; /** * The proxy collbacks to provide checks. */ private List<ProxyCallback> callbacks; /** * Proxy helper to encapsulate proxy initialization */ private ProxyHelper proxyHelper; /** * Default constructor */ public ProxyServiceImpl() { super(); } /** * Constructor with helper */ public ProxyServiceImpl(ProxyHelper proxyHelper) { super(); this.proxyHelper = proxyHelper; proxyHelper.initProxy(this); } /** * Constructor with proxy configuration */ public ProxyServiceImpl(ProxyConfig proxyConfig) { super(); this.setProxyConfig(proxyConfig); } /** * Obtain proxy configuration * * @return the proxy configuration */ public ProxyConfig getProxyConfig() { return proxyConfig; } /** * Change proxy configuration * @param new proxy configuration */ public void setProxyConfig(ProxyConfig proxyConfig) { this.proxyConfig = proxyConfig; loadProxyConfig(); } /** * Load proxy configuration when proxy config has changed */ private void loadProxyConfig() { connectionManager = new MultiThreadedHttpConnectionManager(); HttpConnectionManagerParams params = new HttpConnectionManagerParams(); params.setSoTimeout(proxyConfig.getSoTimeout()); params.setConnectionTimeout(proxyConfig.getConnectionTimeout()); params.setMaxTotalConnections(proxyConfig.getMaxTotalConnections()); params.setDefaultMaxConnectionsPerHost(proxyConfig.getDefaultMaxConnectionsPerHost()); connectionManager.setParams(params); httpClient = new HttpClient(connectionManager); configureCallbacks(); } /** * Configure the proxy callbacks */ private void configureCallbacks() { if (callbacks != null) { // Change callbacks configuration for (ProxyCallback callback : callbacks) { callback.setProxyConfig(proxyConfig); } } } /** * Performs an HTTP request. Read <code>httpServletRequest</code> method. Default method is HTTP GET. * * @param httpServletRequest The {@link HttpServletRequest} object passed in by the servlet engine representing the client request to be proxied * @param httpServletResponse The {@link HttpServletResponse} object by which we can send a proxied response to the client */ public void execute(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws IOException, ServletException { try { this.doMethod(httpServletRequest, httpServletResponse); } catch (HttpErrorException ex) { httpServletResponse.sendError(ex.getCode(), ex.getMessage()); } catch (Exception e) { httpServletResponse.sendError(HttpStatus.SC_SERVICE_UNAVAILABLE, e.getMessage()); } finally { onFinish(); } } /** * * * @param request * @param response * @throws IOException */ public void onInit(HttpServletRequest request, HttpServletResponse response, URL url) throws IOException { for (ProxyCallback callback : callbacks) { callback.onRequest(request, response, url); } } /** * @param method * @throws IOException */ public void onRemoteResponse(HttpMethod method) throws IOException { for (ProxyCallback callback : callbacks) { callback.onRemoteResponse(method); } } /** * @throws IOException */ public void onFinish() throws IOException { for (ProxyCallback callback : callbacks) { callback.onFinish(); } } /** * Performs an HTTP request * * @param httpServletRequest The {@link HttpServletRequest} object passed in by the servlet engine representing the client request to be proxied * @param httpServletResponse The {@link HttpServletResponse} object by which we can send a proxied response to the client */ public void doMethod(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws IOException, ServletException { ProxyMethodConfig methodConfig = proxyHelper.prepareProxyMethod(httpServletRequest, httpServletResponse, this); if (methodConfig != null) { // ////////////////////////////// // Create a request // ////////////////////////////// HttpMethod methodProxyRequest = methodConfig.getMethod(); // ////////////////////////////// // Forward the request headers // ////////////////////////////// final ProxyInfo proxyInfo = setProxyRequestHeaders(methodConfig.getUrl(), httpServletRequest, methodProxyRequest); // ////////////////////////////////////////////////// // Check if this is a mulitpart (file upload) PUT | POST // ////////////////////////////////////////////////// if (methodProxyRequest instanceof EntityEnclosingMethod) { if (ServletFileUpload.isMultipartContent(httpServletRequest)) { this.handleMultipart((EntityEnclosingMethod) methodProxyRequest, httpServletRequest); } else { this.handleStandard((EntityEnclosingMethod) methodProxyRequest, httpServletRequest); } } // ////////////////////////////// // Execute the proxy request // ////////////////////////////// this.executeProxyRequest(methodProxyRequest, httpServletRequest, httpServletResponse, methodConfig.getUser(), methodConfig.getPassword(), proxyInfo); } } /** * Sets up the given {@link PostMethod} to send the same multipart POST data as was sent in the given {@link HttpServletRequest} * * @param postMethodProxyRequest The {@link PostMethod} that we are configuring to send a multipart POST request * @param httpServletRequest The {@link HttpServletRequest} that contains the mutlipart POST data to be sent via the {@link PostMethod} */ private void handleMultipart(EntityEnclosingMethod methodProxyRequest, HttpServletRequest httpServletRequest) throws ServletException { // //////////////////////////////////////////// // Create a factory for disk-based file items // //////////////////////////////////////////// DiskFileItemFactory diskFileItemFactory = new DiskFileItemFactory(); // ///////////////////////////// // Set factory constraints // ///////////////////////////// diskFileItemFactory.setSizeThreshold(this.getMaxFileUploadSize()); diskFileItemFactory.setRepository(Utils.DEFAULT_FILE_UPLOAD_TEMP_DIRECTORY); // ////////////////////////////////// // Create a new file upload handler // ////////////////////////////////// ServletFileUpload servletFileUpload = new ServletFileUpload(diskFileItemFactory); // ////////////////////////// // Parse the request // ////////////////////////// try { // ///////////////////////////////////// // Get the multipart items as a list // ///////////////////////////////////// List<FileItem> listFileItems = (List<FileItem>) servletFileUpload.parseRequest(httpServletRequest); // ///////////////////////////////////////// // Create a list to hold all of the parts // ///////////////////////////////////////// List<Part> listParts = new ArrayList<Part>(); // ///////////////////////////////////////// // Iterate the multipart items list // ///////////////////////////////////////// for (FileItem fileItemCurrent : listFileItems) { // ////////////////////////////////////// // If the current item is a form field, // then create a string part // ////////////////////////////////////// if (fileItemCurrent.isFormField()) { StringPart stringPart = new StringPart( // The field name fileItemCurrent.getFieldName(), // The field value fileItemCurrent.getString()); // //////////////////////////// // Add the part to the list // //////////////////////////// listParts.add(stringPart); } else { // ///////////////////////////////////////////////////// // The item is a file upload, so we create a FilePart // ///////////////////////////////////////////////////// FilePart filePart = new FilePart( // ///////////////////// // The field name // ///////////////////// fileItemCurrent.getFieldName(), new ByteArrayPartSource( // The uploaded file name fileItemCurrent.getName(), // The uploaded file contents fileItemCurrent.get())); // ///////////////////////////// // Add the part to the list // ///////////////////////////// listParts.add(filePart); } } MultipartRequestEntity multipartRequestEntity = new MultipartRequestEntity( listParts.toArray(new Part[] {}), methodProxyRequest.getParams()); methodProxyRequest.setRequestEntity(multipartRequestEntity); // //////////////////////////////////////////////////////////////////////// // The current content-type header (received from the client) IS of // type "multipart/form-data", but the content-type header also // contains the chunk boundary string of the chunks. Currently, this // header is using the boundary of the client request, since we // blindly copied all headers from the client request to the proxy // request. However, we are creating a new request with a new chunk // boundary string, so it is necessary that we re-set the // content-type string to reflect the new chunk boundary string // //////////////////////////////////////////////////////////////////////// methodProxyRequest.setRequestHeader(Utils.CONTENT_TYPE_HEADER_NAME, multipartRequestEntity.getContentType()); } catch (FileUploadException fileUploadException) { throw new ServletException(fileUploadException); } } /** * Sets up the given {@link PostMethod} to send the same standard POST data as was sent in the given {@link HttpServletRequest} * * @param postMethodProxyRequest The {@link PostMethod} that we are configuring to send a standard POST request * @param httpServletRequest The {@link HttpServletRequest} that contains the POST data to be sent via the {@link PostMethod} * @throws IOException */ private void handleStandard(EntityEnclosingMethod methodProxyRequest, HttpServletRequest httpServletRequest) throws IOException { try { methodProxyRequest.setRequestEntity(new InputStreamRequestEntity(httpServletRequest.getInputStream())); //LOGGER.info("original request content length:" + httpServletRequest.getContentLength()); //LOGGER.info("proxied request content length:" +methodProxyRequest.getRequestEntity().getContentLength()+""); } catch (IOException e) { throw new IOException(e); } } /** * Executes the {@link HttpMethod} passed in and sends the proxy response back to the client via the given {@link HttpServletResponse} * * @param httpMethodProxyRequest An object representing the proxy request to be made * @param httpServletResponse An object by which we can send the proxied response back to the client * @param digest * @throws IOException Can be thrown by the {@link HttpClient}.executeMethod * @throws ServletException Can be thrown to indicate that another error has occurred */ private void executeProxyRequest(HttpMethod httpMethodProxyRequest, HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, String user, String password, ProxyInfo proxyInfo) throws IOException, ServletException { if (user != null && password != null) { UsernamePasswordCredentials upc = new UsernamePasswordCredentials(user, password); httpClient.getState().setCredentials(AuthScope.ANY, upc); } httpMethodProxyRequest.setFollowRedirects(false); InputStream inputStreamServerResponse = null; ByteArrayOutputStream baos = null; try { // ////////////////////////// // Execute the request // ////////////////////////// int intProxyResponseCode = httpClient.executeMethod(httpMethodProxyRequest); onRemoteResponse(httpMethodProxyRequest); // //////////////////////////////////////////////////////////////////////////////// // Check if the proxy response is a redirect // The following code is adapted from // org.tigris.noodle.filters.CheckForRedirect // Hooray for open source software // //////////////////////////////////////////////////////////////////////////////// if (intProxyResponseCode >= HttpServletResponse.SC_MULTIPLE_CHOICES /* 300 */ && intProxyResponseCode < HttpServletResponse.SC_NOT_MODIFIED /* 304 */) { String stringStatusCode = Integer.toString(intProxyResponseCode); String stringLocation = httpMethodProxyRequest.getResponseHeader(Utils.LOCATION_HEADER).getValue(); if (stringLocation == null) { throw new ServletException("Recieved status code: " + stringStatusCode + " but no " + Utils.LOCATION_HEADER + " header was found in the response"); } // ///////////////////////////////////////////// // Modify the redirect to go to this proxy // servlet rather that the proxied host // ///////////////////////////////////////////// String stringMyHostName = httpServletRequest.getServerName(); if (httpServletRequest.getServerPort() != 80) { stringMyHostName += ":" + httpServletRequest.getServerPort(); } stringMyHostName += httpServletRequest.getContextPath(); httpServletResponse.sendRedirect(stringLocation.replace( Utils.getProxyHostAndPort(proxyInfo) + proxyInfo.getProxyPath(), stringMyHostName)); return; } else if (intProxyResponseCode == HttpServletResponse.SC_NOT_MODIFIED) { // /////////////////////////////////////////////////////////////// // 304 needs special handling. See: // http://www.ics.uci.edu/pub/ietf/http/rfc1945.html#Code304 // We get a 304 whenever passed an 'If-Modified-Since' // header and the data on disk has not changed; server // responds w/ a 304 saying I'm not going to send the // body because the file has not changed. // /////////////////////////////////////////////////////////////// httpServletResponse.setIntHeader(Utils.CONTENT_LENGTH_HEADER_NAME, 0); httpServletResponse.setStatus(HttpServletResponse.SC_NOT_MODIFIED); return; } // ///////////////////////////////////////////// // Pass the response code back to the client // ///////////////////////////////////////////// httpServletResponse.setStatus(intProxyResponseCode); // ///////////////////////////////////////////// // Pass response headers back to the client // ///////////////////////////////////////////// Header[] headerArrayResponse = httpMethodProxyRequest.getResponseHeaders(); for (Header header : headerArrayResponse) { // ///////////////////////// // Skip GZIP Responses // ///////////////////////// if (header.getName().equalsIgnoreCase(Utils.HTTP_HEADER_ACCEPT_ENCODING) && header.getValue().toLowerCase().contains("gzip")) continue; else if (header.getName().equalsIgnoreCase(Utils.HTTP_HEADER_CONTENT_ENCODING) && header.getValue().toLowerCase().contains("gzip")) continue; else if (header.getName().equalsIgnoreCase(Utils.HTTP_HEADER_TRANSFER_ENCODING)) continue; // else if (header.getName().equalsIgnoreCase(Utils.HTTP_HEADER_WWW_AUTHENTICATE)) // continue; else httpServletResponse.setHeader(header.getName(), header.getValue()); } // /////////////////////////////////// // Send the content to the client // /////////////////////////////////// inputStreamServerResponse = httpMethodProxyRequest.getResponseBodyAsStream(); if (inputStreamServerResponse != null) { byte[] b = new byte[proxyConfig.getDefaultStreamByteSize()]; baos = new ByteArrayOutputStream(b.length); int read = 0; while ((read = inputStreamServerResponse.read(b)) > 0) { baos.write(b, 0, read); baos.flush(); } baos.writeTo(httpServletResponse.getOutputStream()); } } catch (HttpException e) { if (LOGGER.isLoggable(Level.SEVERE)) LOGGER.log(Level.SEVERE, "Error executing HTTP method ", e); } finally { try { if (inputStreamServerResponse != null) inputStreamServerResponse.close(); } catch (IOException e) { if (LOGGER.isLoggable(Level.SEVERE)) LOGGER.log(Level.SEVERE, "Error closing request input stream ", e); throw new ServletException(e.getMessage()); } try { if (baos != null) { baos.flush(); baos.close(); } } catch (IOException e) { if (LOGGER.isLoggable(Level.SEVERE)) LOGGER.log(Level.SEVERE, "Error closing response stream ", e); throw new ServletException(e.getMessage()); } httpMethodProxyRequest.releaseConnection(); } } /** * Retrieves all of the headers from the servlet request and sets them on the proxy request * * @param httpServletRequest The request object representing the client's request to the servlet engine * @param httpMethodProxyRequest The request that we are about to send to the proxy host * @return ProxyInfo */ @SuppressWarnings("rawtypes") private ProxyInfo setProxyRequestHeaders(URL url, HttpServletRequest httpServletRequest, HttpMethod httpMethodProxyRequest) { final String proxyHost = url.getHost(); final int proxyPort = url.getPort(); final String proxyPath = url.getPath(); final ProxyInfo proxyInfo = new ProxyInfo(proxyHost, proxyPath, proxyPort); // //////////////////////////////////////// // Get an Enumeration of all of the header // names sent by the client. // //////////////////////////////////////// Enumeration enumerationOfHeaderNames = httpServletRequest.getHeaderNames(); while (enumerationOfHeaderNames.hasMoreElements()) { String stringHeaderName = (String) enumerationOfHeaderNames.nextElement(); if (stringHeaderName.equalsIgnoreCase(Utils.CONTENT_LENGTH_HEADER_NAME)) continue; // //////////////////////////////////////////////////////////////////////// // As per the Java Servlet API 2.5 documentation: // Some headers, such as Accept-Language can be sent by clients // as several headers each with a different value rather than // sending the header as a comma separated list. // Thus, we get an Enumeration of the header values sent by the client // //////////////////////////////////////////////////////////////////////// Enumeration enumerationOfHeaderValues = httpServletRequest.getHeaders(stringHeaderName); while (enumerationOfHeaderValues.hasMoreElements()) { String stringHeaderValue = (String) enumerationOfHeaderValues.nextElement(); // //////////////////////////////////////////////////////////////// // In case the proxy host is running multiple virtual servers, // rewrite the Host header to ensure that we get content from // the correct virtual server // //////////////////////////////////////////////////////////////// if (stringHeaderName.equalsIgnoreCase(Utils.HOST_HEADER_NAME)) { stringHeaderValue = Utils.getProxyHostAndPort(proxyInfo); } // //////////////////////// // Skip GZIP Responses // //////////////////////// if (stringHeaderName.equalsIgnoreCase(Utils.HTTP_HEADER_ACCEPT_ENCODING) && stringHeaderValue.toLowerCase().contains("gzip")) continue; if (stringHeaderName.equalsIgnoreCase(Utils.HTTP_HEADER_CONTENT_ENCODING) && stringHeaderValue.toLowerCase().contains("gzip")) continue; if (stringHeaderName.equalsIgnoreCase(Utils.HTTP_HEADER_TRANSFER_ENCODING)) continue; Header header = new Header(stringHeaderName, stringHeaderValue); // ///////////////////////////////////////////// // Set the same header on the proxy request // ///////////////////////////////////////////// httpMethodProxyRequest.setRequestHeader(header); } } return proxyInfo; } /** * @return int the maximum file upload size. */ public int getMaxFileUploadSize() { return maxFileUploadSize; } /** * @return the callbacks */ public List<ProxyCallback> getCallbacks() { return callbacks; } /** * @param callbacks the callbacks to set */ public void setCallbacks(List<ProxyCallback> callbacks) { this.callbacks = callbacks; configureCallbacks(); } /** * @return the proxyHelper */ public ProxyHelper getProxyHelper() { return proxyHelper; } /** * @param proxyHelper the proxyHelper to set */ public void setProxyHelper(ProxyHelper proxyHelper) { this.proxyHelper = proxyHelper; } }