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.processor; import com.googlecode.concurrentlinkedhashmap.ConcurrentLinkedHashMap; import com.liferay.portal.kernel.util.StringBundler; import java.io.BufferedReader; import java.io.InputStreamReader; import java.io.PrintWriter; import java.io.StringWriter; import java.io.Writer; import java.util.ArrayList; import java.util.List; import java.util.Map; import java.util.Queue; import java.util.concurrent.LinkedBlockingQueue; import org.apache.commons.lang3.StringUtils; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.json.JSONObject; /** * @author Brian Wing Shun Chan * @author Peter Shin */ public abstract class BaseShellDoulosRequestProcessor extends BaseDoulosRequestProcessor { public BaseShellDoulosRequestProcessor() { ConcurrentLinkedHashMap.Builder<String, ShellStatus> builder = new ConcurrentLinkedHashMap.Builder<String, ShellStatus>(); builder.maximumWeightedCapacity(getShellStatusesSize()); _shellStatuses = builder.build(); _thread.start(); } @Override public void destroy() { _destroy = true; while (!_destroyed) { try { if (_log.isInfoEnabled()) { _log.info("Waiting for background thread to destroy"); } Thread.sleep(getThreadDestroyInterval()); } catch (InterruptedException ie) { _log.error(ie, ie); } } if (_log.isInfoEnabled()) { _log.info("Background thread is destroyed"); } super.destroy(); } @Override public void process(String method, String pathInfo, Map<String, String[]> parameterMap, JSONObject payloadJSONObject, JSONObject responseJSONObject) throws Exception { if (!isValid(payloadJSONObject)) { if (_log.isInfoEnabled()) { _log.info("Skip invalid payload"); } responseJSONObject.put("queue", new ArrayList<String>(_shellStatuses.keySet())); return; } ShellStatus shellStatus = queue(payloadJSONObject); populateResponseJSONObject(responseJSONObject, shellStatus); responseJSONObject.put("queueSize", _queue.size()); if (_log.isInfoEnabled()) { _log.info(StringBundler.concat("Status ", shellStatus.status, " for ", shellStatus.key)); } } protected void addShellStatus(String key, ShellStatus shellStatus) { _shellStatuses.put(key, shellStatus); _queue.add(shellStatus); } protected abstract ShellStatus createShellStatus(JSONObject payloadJSONObject); protected void execute(ShellStatus shellStatus) throws Exception { shellStatus.status = "executing"; List<String> shellCommandsList = getShellCommands(shellStatus); shellCommandsList.add(0, "/bin/bash"); shellCommandsList.add(1, "-x"); shellCommandsList.add(2, "-c"); String[] shellCommands = shellCommandsList.toArray(new String[shellCommandsList.size()]); shellStatus.shellCommands = StringUtils.join(shellCommands, "\n"); ProcessBuilder processBuilder = new ProcessBuilder(shellCommands); processBuilder.redirectErrorStream(true); Process process = processBuilder.start(); StringBuilder sb = new StringBuilder(); String line = null; BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(process.getInputStream())); while ((line = bufferedReader.readLine()) != null) { sb.append(line); sb.append("\n"); } bufferedReader.close(); try { if (_log.isDebugEnabled()) { _log.debug("Wait for process to finish"); } process.waitFor(); shellStatus.exitValue = String.valueOf(process.exitValue()); shellStatus.output = sb.toString(); shellStatus.status = "finished"; } catch (Exception e) { Writer writer = new StringWriter(); PrintWriter printWriter = new PrintWriter(writer); e.printStackTrace(printWriter); shellStatus.exception = writer.toString(); shellStatus.status = "exception"; } } protected long getExpiredTime() { return _EXPIRED_TIME; } protected abstract String getKey(JSONObject payloadJSONObject); protected abstract List<String> getShellCommands(ShellStatus shellStatus); protected long getShellStatusesSize() { return _SHELL_STATUSES_SIZE; } protected int getThreadDestroyInterval() { return _THREAD_DESTROY_INTERVAL; } protected int getThreadExecuteInterval() { return _THREAD_EXECUTE_INTERVAL; } protected abstract boolean isRemoveFromQueue(JSONObject payloadJSONObject); protected abstract boolean isValid(JSONObject payloadJSONObject); protected void populateResponseJSONObject(JSONObject responseJSONObject, ShellStatus shellStatus) { responseJSONObject.put("exception", shellStatus.exception); responseJSONObject.put("exitValue", shellStatus.exitValue); responseJSONObject.put("output", shellStatus.output); responseJSONObject.put("shellCommands", shellStatus.shellCommands); responseJSONObject.put("status", shellStatus.status); } protected ShellStatus queue(JSONObject payloadJSONObject) { ShellStatus shellStatus = null; String key = getKey(payloadJSONObject); synchronized (this) { shellStatus = _shellStatuses.get(key); if (isRemoveFromQueue(payloadJSONObject)) { if (shellStatus != null) { removeShellStatus(key, shellStatus); } shellStatus = createShellStatus(payloadJSONObject); shellStatus.status = "removed"; return shellStatus; } if (shellStatus != null) { long expiredTime = getExpiredTime(); if ((expiredTime > 0) && (shellStatus.time < getExpiredTime())) { removeShellStatus(key, shellStatus); shellStatus = null; } } if (shellStatus == null) { if (_log.isInfoEnabled()) { _log.info("Adding " + key + " to queue"); } shellStatus = createShellStatus(payloadJSONObject); addShellStatus(key, shellStatus); } } return shellStatus; } protected void removeShellStatus(String key, ShellStatus shellStatus) { _shellStatuses.remove(key); _queue.remove(shellStatus); } protected class ShellStatus { public ShellStatus(String key) { this.key = key; } public String exception = ""; public String exitValue = ""; public String key = ""; public String output = ""; public String shellCommands = ""; public String status = "queued"; public long time = System.currentTimeMillis(); } private static final int _EXPIRED_TIME = 0; private static final long _SHELL_STATUSES_SIZE = 1000; private static final int _THREAD_DESTROY_INTERVAL = 10 * 1000; private static final int _THREAD_EXECUTE_INTERVAL = 3 * 1000; private static final Log _log = LogFactory.getLog(BaseShellDoulosRequestProcessor.class); private boolean _destroy; private boolean _destroyed; private final Queue<ShellStatus> _queue = new LinkedBlockingQueue<>(); private final Map<String, ShellStatus> _shellStatuses; private final Thread _thread = new Thread() { @Override public void run() { while (true) { if (_destroy) { break; } ShellStatus shellStatus = _queue.poll(); if (shellStatus == null) { try { Thread.sleep(getThreadExecuteInterval()); } catch (InterruptedException ie) { _log.error("Terminating background thread due to unexpected " + "interruption", ie); break; } continue; } System.out.println("Queue size " + _queue.size()); try { if (_log.isInfoEnabled()) { _log.info("Executing " + shellStatus.key); } execute(shellStatus); } catch (Exception e) { _log.error(e, e); } } _destroyed = true; } }; }