Java tutorial
/** * Copyright (c) 2000-present Liferay, Inc. All rights reserved. * * This library is free software; you can redistribute it and/or modify it under * the terms of the GNU Lesser General Public License as published by the Free * Software Foundation; either version 2.1 of the License, or (at your option) * any later version. * * This library 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 Lesser General Public License for more * details. */ package com.liferay.petra.doulos.servlet; import com.liferay.petra.doulos.processor.DoulosRequestProcessor; import com.liferay.portal.kernel.util.StringBundler; import java.io.BufferedOutputStream; import java.io.BufferedReader; import java.io.ByteArrayInputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.io.PrintWriter; import java.io.StringWriter; import java.util.HashMap; import java.util.Map; import javax.servlet.ServletConfig; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.json.JSONObject; /** * @author Brian Wing Shun Chan */ public abstract class DoulosServlet extends HttpServlet { @Override public void destroy() { for (Map.Entry<String, DoulosRequestProcessor> entry : _doulosRequestProcessors.entrySet()) { DoulosRequestProcessor doulosRequestProcessor = entry.getValue(); try { doulosRequestProcessor.destroy(); } catch (Exception e) { _log.error(e, e); } } super.destroy(); } @Override public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException { service(request, response); } @Override public void doPost(HttpServletRequest request, HttpServletResponse response) throws IOException { service(request, response); } @Override public void init(ServletConfig servletConfig) throws ServletException { try { registerDoulosRequestProcessors(); } catch (Exception e) { throw new ServletException(e); } String validIpsString = servletConfig.getInitParameter("validIps"); if (validIpsString != null) { _validIps = validIpsString.split(","); } else { _validIps = new String[0]; } } protected boolean isBlank(String s) { if ((s == null) || s.equals("")) { return true; } return false; } protected boolean isValidIP(String remoteAddr) { if (_validIps.length == 0) { return true; } for (String validIp : _validIps) { if (remoteAddr.equals(validIp) || remoteAddr.startsWith(validIp + ".")) { return true; } } return false; } protected void registerDoulosRequestProcessor(String doulosRequestProcessorKey, DoulosRequestProcessor doulosRequestProcessor) { _doulosRequestProcessors.put(doulosRequestProcessorKey, doulosRequestProcessor); } protected abstract void registerDoulosRequestProcessors() throws Exception; protected void sendError(HttpServletResponse response, String message) throws IOException { write(response, new ByteArrayInputStream(message.getBytes())); } @Override protected void service(HttpServletRequest request, HttpServletResponse response) throws IOException { String remoteAddr = request.getRemoteAddr(); if (_log.isInfoEnabled()) { _log.info("Remote address: " + remoteAddr); } if (!isValidIP(remoteAddr)) { sendError(response, "IP " + remoteAddr + " is invalid."); return; } String pathInfo = request.getPathInfo(); if (pathInfo.length() > 1) { if (pathInfo.endsWith("/")) { pathInfo = pathInfo.substring(0, pathInfo.length() - 1); } } for (Map.Entry<String, DoulosRequestProcessor> entry : _doulosRequestProcessors.entrySet()) { String doulosRequestProcessorKey = entry.getKey(); if (!pathInfo.startsWith(doulosRequestProcessorKey)) { continue; } DoulosRequestProcessor doulosRequestProcessor = entry.getValue(); if (_log.isInfoEnabled()) { _log.info(StringBundler.concat("Processing ", String.valueOf(request.getRequestURL()), " with ", String.valueOf(doulosRequestProcessor))); } try { String payload = request.getParameter("payload"); if (_log.isInfoEnabled()) { _log.info("Payload parameter: " + payload); } if (payload == null) { StringBuilder sb = new StringBuilder(); String line = null; BufferedReader bufferedReader = request.getReader(); while ((line = bufferedReader.readLine()) != null) { sb.append(line); } bufferedReader.close(); payload = sb.toString(); if (_log.isInfoEnabled()) { _log.info("Payload body: " + payload); } } JSONObject payloadJSONObject = null; if (payload.length() > 0) { payloadJSONObject = new JSONObject(payload); } else { payloadJSONObject = new JSONObject(); } JSONObject responseJSONObject = new JSONObject(); doulosRequestProcessor.process(request.getMethod(), pathInfo.substring(doulosRequestProcessorKey.length()), request.getParameterMap(), payloadJSONObject, responseJSONObject); String redirect = responseJSONObject.optString("doulosRedirect"); if (!isBlank(redirect)) { response.sendRedirect(redirect); return; } String json = responseJSONObject.toString(); write(response, new ByteArrayInputStream(json.getBytes("UTF-8"))); } catch (Exception e) { StringWriter stringWriter = new StringWriter(); PrintWriter printWriter = new PrintWriter(stringWriter); e.printStackTrace(printWriter); String output = stringWriter.toString(); if (_log.isInfoEnabled()) { _log.info(output); } sendError(response, output); } return; } sendError(response, "Unregistered path " + request.getPathInfo() + "."); } protected void write(HttpServletResponse response, InputStream inputStream) throws IOException { OutputStream outputStream = null; try { response.setHeader("Cache-Control", "public"); if (!response.isCommitted()) { outputStream = new BufferedOutputStream(response.getOutputStream()); int c = inputStream.read(); while (c != -1) { outputStream.write(c); c = inputStream.read(); } } } finally { try { if (outputStream != null) { outputStream.flush(); } } catch (Exception e) { if (_log.isWarnEnabled()) { _log.warn(e); } } try { if (outputStream != null) { outputStream.close(); } } catch (Exception e) { if (_log.isWarnEnabled()) { _log.warn(e); } } try { if (inputStream != null) { inputStream.close(); } } catch (Exception e) { if (_log.isWarnEnabled()) { _log.warn(e); } } } } private static final Log _log = LogFactory.getLog(DoulosServlet.class); private final Map<String, DoulosRequestProcessor> _doulosRequestProcessors = new HashMap<>(); private String[] _validIps; }