Java tutorial
/************************************************************************* * tranSMART - translational medicine data mart * * Copyright 2008-2012 Janssen Research & Development, LLC. * * This product includes software developed at Janssen Research & Development, LLC. * * 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, along with the following terms: * 1. You may convey a work based on this program in accordance with section 5, provided that you retain the above notices. * 2. You may convey verbatim copies of this program code as you receive it, in any medium, provided that you retain the above notices. * * 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/>. * * ******************************************************************/ /* Copyright 2007 You may not modify, use, reproduce, or distribute this software except in compliance with the terms of the License at: http://developer.sun.com/berkeley_license.html $Id: XmlHttpProxyServlet.java 9178 2011-08-24 13:50:06Z mmcduffie $ */ package com.recomdata.datasetexplorer.proxy; import org.json.JSONObject; import javax.servlet.ServletConfig; import javax.servlet.ServletContext; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; import java.io.BufferedReader; import java.io.InputStream; import java.io.OutputStream; import java.io.PrintWriter; import java.net.URL; import java.net.URLConnection; import java.util.HashMap; import java.util.Map; import java.util.logging.Logger; /** XmlHttpProxyServlet * @author Greg Murray */ public class XmlHttpProxyServlet extends HttpServlet { private static String XHP_LAST_MODIFIED = "xhp_last_modified_key"; private static String XHP_CONFIG = "xhp.json"; private static boolean allowXDomain = true; private static boolean requireSession = false; private static String responseContentType = "text/xml;charset=UTF-8"; //changed from text/json in jmaki source private static boolean rDebug = false; private Logger logger = null; private XmlHttpProxy xhp = null; private ServletContext ctx; private JSONObject services = null; private String resourcesDir = "/resources/"; private String classpathResourcesDir = "/META-INF/resources/"; public XmlHttpProxyServlet() { if (rDebug) { logger = getLogger(); } } public void init(ServletConfig config) throws ServletException { super.init(config); ctx = config.getServletContext(); // set the response content type if (ctx.getInitParameter("responseContentType") != null) { responseContentType = ctx.getInitParameter("responseContentType"); } // allow for resources dir over-ride at the xhp level otherwise allow // for the jmaki level resources if (ctx.getInitParameter("jmaki-xhp-resources") != null) { resourcesDir = ctx.getInitParameter("jmaki-xhp-resources"); } else if (ctx.getInitParameter("jmaki-resources") != null) { resourcesDir = ctx.getInitParameter("jmaki-resources"); } // allow for resources dir over-ride if (ctx.getInitParameter("jmaki-classpath-resources") != null) { classpathResourcesDir = ctx.getInitParameter("jmaki-classpath-resources"); } String requireSessionString = ctx.getInitParameter("requireSession"); if (requireSessionString != null) { if ("false".equals(requireSessionString)) { requireSession = false; getLogger().severe("XmlHttpProxyServlet: intialization. Session requirement disabled."); } else if ("true".equals(requireSessionString)) { requireSession = true; getLogger().severe("XmlHttpProxyServlet: intialization. Session requirement enabled."); } } String xdomainString = ctx.getInitParameter("allowXDomain"); if (xdomainString != null) { if ("true".equals(xdomainString)) { allowXDomain = true; getLogger().severe("XmlHttpProxyServlet: intialization. xDomain access is enabled."); } else if ("false".equals(xdomainString)) { allowXDomain = false; getLogger().severe("XmlHttpProxyServlet: intialization. xDomain access is disabled."); } } // if there is a proxyHost and proxyPort specified create an HttpClient with the proxy String proxyHost = ctx.getInitParameter("proxyHost"); String proxyPortString = ctx.getInitParameter("proxyPort"); if (proxyHost != null && proxyPortString != null) { int proxyPort = 8080; try { proxyPort = new Integer(proxyPortString).intValue(); xhp = new XmlHttpProxy(proxyHost, proxyPort); } catch (NumberFormatException nfe) { getLogger().severe("XmlHttpProxyServlet: intialization error. The proxyPort must be a number"); throw new ServletException( "XmlHttpProxyServlet: intialization error. The proxyPort must be a number"); } } else { xhp = new XmlHttpProxy(); } } private void getServices(HttpServletResponse res) { InputStream is = null; try { URL url = ctx.getResource(resourcesDir + XHP_CONFIG); // use classpath if not found locally. if (url == null) url = XmlHttpProxyServlet.class.getResource(classpathResourcesDir + XHP_CONFIG); is = url.openStream(); } catch (Exception ex) { try { getLogger().severe("XmlHttpProxyServlet error loading xhp.json : " + ex); PrintWriter writer = res.getWriter(); writer.write( "XmlHttpProxyServlet Error: Error loading xhp.json. Make sure it is available in the /resources directory of your applicaton."); writer.flush(); } catch (Exception iox) { } } services = xhp.loadServices(is); } public void doGet(HttpServletRequest req, HttpServletResponse res) { doProcess(req, res, false); } public void doPost(HttpServletRequest req, HttpServletResponse res) { doProcess(req, res, true); } public void doProcess(HttpServletRequest req, HttpServletResponse res, boolean isPost) { StringBuffer bodyContent = null; OutputStream out = null; PrintWriter writer = null; String serviceKey = null; try { BufferedReader in = req.getReader(); String line = null; while ((line = in.readLine()) != null) { if (bodyContent == null) bodyContent = new StringBuffer(); bodyContent.append(line); } } catch (Exception e) { } try { if (requireSession) { // check to see if there was a session created for this request // if not assume it was from another domain and blow up // Wrap this to prevent Portlet exeptions HttpSession session = req.getSession(false); if (session == null) { res.setStatus(HttpServletResponse.SC_FORBIDDEN); return; } } serviceKey = req.getParameter("id"); // only to preven regressions - Remove before 1.0 if (serviceKey == null) serviceKey = req.getParameter("key"); // check if the services have been loaded or if they need to be reloaded if (services == null || configUpdated()) { getServices(res); } String urlString = null; String xslURLString = null; String userName = null; String password = null; String format = "json"; String callback = req.getParameter("callback"); String urlParams = req.getParameter("urlparams"); String countString = req.getParameter("count"); // encode the url to prevent spaces from being passed along if (urlParams != null) { urlParams = urlParams.replace(' ', '+'); } try { if (services.has(serviceKey)) { JSONObject service = services.getJSONObject(serviceKey); // default to the service default if no url parameters are specified if (urlParams == null && service.has("defaultURLParams")) { urlParams = service.getString("defaultURLParams"); } String serviceURL = service.getString("url"); // build the URL if (urlParams != null && serviceURL.indexOf("?") == -1) { serviceURL += "?"; } else if (urlParams != null) { serviceURL += "&"; } String apikey = ""; if (service.has("username")) userName = service.getString("username"); if (service.has("password")) password = service.getString("password"); if (service.has("apikey")) apikey = service.getString("apikey"); urlString = serviceURL + apikey; if (urlParams != null) urlString += "&" + urlParams; if (service.has("xslStyleSheet")) { xslURLString = service.getString("xslStyleSheet"); } } //code for passing the url directly through instead of using configuration file else if (req.getParameter("url") != null) { String serviceURL = req.getParameter("url"); // build the URL if (urlParams != null && serviceURL.indexOf("?") == -1) { serviceURL += "?"; } else if (urlParams != null) { serviceURL += "&"; } urlString = serviceURL; if (urlParams != null) urlString += urlParams; } else { writer = res.getWriter(); if (serviceKey == null) writer.write("XmlHttpProxyServlet Error: id parameter specifying serivce required."); else writer.write("XmlHttpProxyServlet Error : service for id '" + serviceKey + "' not found."); writer.flush(); return; } } catch (Exception ex) { getLogger().severe("XmlHttpProxyServlet Error loading service: " + ex); } Map paramsMap = new HashMap(); paramsMap.put("format", format); // do not allow for xdomain unless the context level setting is enabled. if (callback != null && allowXDomain) { paramsMap.put("callback", callback); } if (countString != null) { paramsMap.put("count", countString); } InputStream xslInputStream = null; if (urlString == null) { writer = res.getWriter(); writer.write( "XmlHttpProxyServlet parameters: id[Required] urlparams[Optional] format[Optional] callback[Optional]"); writer.flush(); return; } // default to JSON res.setContentType(responseContentType); out = res.getOutputStream(); // get the stream for the xsl stylesheet if (xslURLString != null) { // check the web root for the resource URL xslURL = null; xslURL = ctx.getResource(resourcesDir + "xsl/" + xslURLString); // if not in the web root check the classpath if (xslURL == null) { xslURL = XmlHttpProxyServlet.class.getResource(classpathResourcesDir + "xsl/" + xslURLString); } if (xslURL != null) { xslInputStream = xslURL.openStream(); } else { String message = "Could not locate the XSL stylesheet provided for service id " + serviceKey + ". Please check the XMLHttpProxy configuration."; getLogger().severe(message); try { out.write(message.getBytes()); out.flush(); return; } catch (java.io.IOException iox) { } } } if (!isPost) { xhp.doGet(urlString, out, xslInputStream, paramsMap, userName, password); } else { if (bodyContent == null) getLogger().info( "XmlHttpProxyServlet attempting to post to url " + urlString + " with no body content"); xhp.doPost(urlString, out, xslInputStream, paramsMap, bodyContent.toString(), req.getContentType(), userName, password); } } catch (Exception iox) { iox.printStackTrace(); getLogger().severe("XmlHttpProxyServlet: caught " + iox); try { writer = res.getWriter(); writer.write(iox.toString()); writer.flush(); } catch (java.io.IOException ix) { ix.printStackTrace(); } return; } finally { try { if (out != null) out.close(); if (writer != null) writer.close(); } catch (java.io.IOException iox) { } } } /** * Check to see if the configuration file has been updated so that it may be reloaded. */ private boolean configUpdated() { try { URL url = ctx.getResource(resourcesDir + XHP_CONFIG); URLConnection con; if (url == null) return false; con = url.openConnection(); long lastModified = con.getLastModified(); long XHP_LAST_MODIFIEDModified = 0; if (ctx.getAttribute(XHP_LAST_MODIFIED) != null) { XHP_LAST_MODIFIEDModified = ((Long) ctx.getAttribute(XHP_LAST_MODIFIED)).longValue(); } else { ctx.setAttribute(XHP_LAST_MODIFIED, new Long(lastModified)); return false; } if (XHP_LAST_MODIFIEDModified < lastModified) { ctx.setAttribute(XHP_LAST_MODIFIED, new Long(lastModified)); return true; } } catch (Exception ex) { getLogger().severe("XmlHttpProxyServlet error checking configuration: " + ex); } return false; } public Logger getLogger() { if (logger == null) { logger = Logger.getLogger("jmaki.services.xhp.Log"); } return logger; } private void logMessage(String message) { if (rDebug) { getLogger().info(message); } } }