Java tutorial
/* * RHQ Management Platform * Copyright (C) 2005-2008 Red Hat, Inc. * All rights reserved. * * 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 version 2 of the License. * * 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, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ package org.rhq.enterprise.client.commands; import java.io.File; import java.io.FileNotFoundException; import java.io.FileReader; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.io.Reader; import java.util.Arrays; import javax.script.ScriptContext; import javax.script.ScriptEngine; import javax.script.ScriptException; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.rhq.bindings.ScriptEngineFactory; import org.rhq.bindings.StandardBindings; import org.rhq.bindings.client.RhqManagers; import org.rhq.bindings.output.TabularWriter; import org.rhq.bindings.util.PackageFinder; import org.rhq.enterprise.client.ClientMain; import org.rhq.enterprise.client.Controller; import org.rhq.enterprise.client.proxy.ConfigurationEditor; import org.rhq.enterprise.client.proxy.EditableResourceClientFactory; import org.rhq.enterprise.client.script.CLIScriptException; import org.rhq.enterprise.client.script.CmdLineParser; import org.rhq.enterprise.client.script.CommandLineParseException; import org.rhq.enterprise.client.script.NamedScriptArg; import org.rhq.enterprise.client.script.ScriptArg; import org.rhq.enterprise.client.script.ScriptCmdLine; /** * @author Greg Hinkle * @author Lukas Krejci */ public class ScriptCommand implements ClientCommand { private ScriptEngine jsEngine; private StandardBindings bindings; private final Log log = LogFactory.getLog(ScriptCommand.class); private StringBuilder script = new StringBuilder(); private boolean isMultilineScript = false; private boolean inMultilineScript = false; public ScriptEngine getScriptEngine() { if (jsEngine == null) { try { jsEngine = ScriptEngineFactory.getScriptEngine("JavaScript", new PackageFinder(Arrays.asList(getLibDir())), null); } catch (ScriptException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } } return jsEngine; } public String getPromptCommandString() { return "exec"; } public boolean execute(ClientMain client, String[] args) { // for a command line session we don't want to reset the bindings for each executed command line, the // state, e.g. exporter settings, should be maintained from line to line. Note that scriptFiles // executed via 'exec -f' are treated like extensions of the command line session. They inherit the // current bindings and any modifications made by the script file will affect the command line session // after the script file has completed. if (null == bindings) { initBindings(client); } if (isScriptFileCommandLine(args)) { try { CmdLineParser cmdLineParser = new CmdLineParser(); ScriptCmdLine scriptCmdLine = cmdLineParser.parse(args); bindScriptArgs(scriptCmdLine); executeUtilScripts(); FileReader reader = new FileReader(scriptCmdLine.getScriptFileName()); try { return executeScriptFile(reader, client); } finally { try { reader.close(); } catch (IOException ignore) { } } } catch (FileNotFoundException e) { client.getPrintWriter().println(e.getMessage()); if (log.isDebugEnabled()) { log.debug("Unable to locate script file: " + e.getMessage()); } } catch (CommandLineParseException e) { if (client.isInteractiveMode()) { client.getPrintWriter().println("parse error: " + e.getMessage()); if (log.isDebugEnabled()) { log.debug("A parse error occurred.", e); } } else { throw new CLIScriptException(e); } } return true; } isMultilineScript = "\\".equals(args[args.length - 1]); inMultilineScript = inMultilineScript || isMultilineScript; if (!isMultilineScript && !inMultilineScript) { script = new StringBuilder(); } if (isMultilineScript) { args = Arrays.copyOfRange(args, 0, args.length - 1); } for (int i = ("exec".equals(args[0]) ? 1 : 0); i < args.length; i++) { script.append(args[i]); script.append(" "); } if (isMultilineScript) { return true; } try { Object result = getScriptEngine().eval(script.toString()); inMultilineScript = false; script = new StringBuilder(); if (result != null) { // client.getPrintWriter().print("result: "); TabularWriter writer = new TabularWriter(client.getPrintWriter()); if (client.isInteractiveMode()) { writer.setWidth(client.getConsoleWidth()); } writer.print(result); } } catch (ScriptException e) { String message = e.getCause() != null ? e.getCause().getMessage() : e.getMessage(); message = message.replace("sun.org.mozilla.javascript.internal.EcmaError: ", ""); message = message.replace("(<Unknown source>#1) in <Unknown source> at line number 1", ""); client.getPrintWriter().println(message); client.getPrintWriter().println(script); for (int i = 0; i < e.getColumnNumber(); i++) { client.getPrintWriter().print(" "); } client.getPrintWriter().println("^"); script = new StringBuilder(); inMultilineScript = false; } client.getPrintWriter().println(); return true; } private void initBindings(ClientMain client) { bindings = new StandardBindings(client.getPrintWriter(), client.getRemoteClient()); // init pretty width with console setting bindings.getPretty().getValue().setWidth(client.getConsoleWidth()); // replace ResourceClientFactory with Editable version or none at all if (client.getRemoteClient() != null) { bindings.getProxyFactory().setValue(new EditableResourceClientFactory(client)); } else { bindings.getProxyFactory().setValue(null); } //non-standard bindings for console bindings.put("configurationEditor", new ConfigurationEditor(client)); bindings.put("rhq", new Controller(client)); ScriptEngine engine = getScriptEngine(); ScriptEngineFactory.injectStandardBindings(engine, bindings, false); ScriptEngineFactory.bindIndirectionMethods(engine, "configurationEditor"); ScriptEngineFactory.bindIndirectionMethods(engine, "rhq"); } public void initClient(ClientMain client) { if (null == bindings) { initBindings(client); } else { ScriptEngine engine = getScriptEngine(); // remove any current manager bindings from the engine, they may not be valid for the // new client. The new standard bindings will include any new managers. ScriptEngineFactory.removeBindings(engine, bindings.getManagers().keySet()); bindings.setFacade(client.getPrintWriter(), client.getRemoteClient()); // update the engine with the new client bindings. Keep the existing engine bindings as they // may contain bindings outside this standard set (like any var created by the script or command line user) ScriptEngineFactory.injectStandardBindings(engine, bindings, false); } return; } private void executeUtilScripts() { InputStream stream = getClass().getResourceAsStream("test_utils.js"); InputStreamReader reader = new InputStreamReader(stream); try { getScriptEngine().eval(reader); } catch (ScriptException e) { log.warn("An error occurred while executing test_utils.js", e); } } private boolean isScriptFileCommandLine(String[] args) { if (args == null || args.length < 3) { return false; } for (int i = 0; i < args.length; ++i) { if (args[i].equals("-f")) { return true; } } return false; } private void bindScriptArgs(ScriptCmdLine cmdLine) { bindArgsArray(cmdLine); if (cmdLine.getArgType() == ScriptCmdLine.ArgType.NAMED) { bindNamedArgs(cmdLine); } getScriptEngine().put("script", new File(cmdLine.getScriptFileName()).getName()); } private void bindArgsArray(ScriptCmdLine cmdLine) { String[] args = new String[cmdLine.getArgs().size()]; int i = 0; for (ScriptArg arg : cmdLine.getArgs()) { args[i++] = arg.getValue(); } getScriptEngine().put("args", args); } private void bindNamedArgs(ScriptCmdLine cmdLine) { for (ScriptArg arg : cmdLine.getArgs()) { NamedScriptArg namedArg = (NamedScriptArg) arg; getScriptEngine().put(namedArg.getName(), namedArg.getValue()); } } private boolean executeScriptFile(Reader reader, ClientMain client) { try { Object result = getScriptEngine().eval(reader); if (result != null) { if (client.isInteractiveMode()) { new TabularWriter(client.getPrintWriter()).print(result); } } } catch (ScriptException e) { if (client.isInteractiveMode()) { client.getPrintWriter().println(e.getMessage()); client.getPrintWriter().println("^"); } else { throw new CLIScriptException(e); } } return true; } public String getSyntax() { return getPromptCommandString() + " <statement> | [-s<indexed|named>] -f <file> [args]"; } public String getHelp() { return "Execute a statement or a script"; } public String getDetailedHelp() { return "Execute a statement or a script. The following service managers are available: " + Arrays.toString(RhqManagers.values()); } public ScriptContext getContext() { return getScriptEngine().getContext(); } private File getLibDir() { String cwd = System.getProperty("user.dir"); return new File(cwd, "lib"); } }