Java tutorial
/* * 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 com.aionemu.commons.scripting; import java.io.BufferedReader; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.FileReader; import java.io.IOException; import java.io.InputStreamReader; import java.io.InvalidClassException; import java.io.LineNumberReader; import java.io.ObjectInputStream; import java.io.PrintWriter; import java.io.StringWriter; import java.util.LinkedList; import java.util.List; import java.util.Map; import javax.script.Compilable; import javax.script.CompiledScript; import javax.script.ScriptContext; import javax.script.ScriptEngine; import javax.script.ScriptEngineFactory; import javax.script.ScriptEngineManager; import javax.script.ScriptException; import javax.script.SimpleScriptContext; import javolution.util.FastMap; import org.apache.commons.io.IOUtils; import org.apache.log4j.Logger; /** * Caches script engines and provides funcionality for executing and managing scripts.<BR> * * @author KenM */ public final class AionScriptEngineManager { /** * Logger */ private static final Logger log = Logger.getLogger(ScriptEngineManager.class); public final static File SCRIPT_FOLDER; static { SCRIPT_FOLDER = new File("data/scripts"); } public static AionScriptEngineManager getInstance() { return SingletonHolder._instance; } private final Map<String, ScriptEngine> _nameEngines = new FastMap<String, ScriptEngine>(); private final Map<String, ScriptEngine> _extEngines = new FastMap<String, ScriptEngine>(); private final List<ScriptManager<?>> _scriptManagers = new LinkedList<ScriptManager<?>>(); private final CompiledScriptCache _cache; private File _currentLoadingScript; // Configs // TODO move to config file /** * Informs(logs) the scripts being loaded.<BR> * Apply only when executing script from files.<BR> */ private final boolean VERBOSE_LOADING = false; /** * If the script engine supports compilation the script is compiled before execution.<BR> */ private final boolean ATTEMPT_COMPILATION = true; /** * Use Compiled Scripts Cache.<BR> * Only works if ATTEMPT_COMPILATION is true.<BR> * DISABLED DUE ISSUES (if a superclass file changes subclasses are not recompiled where they should) */ private final boolean USE_COMPILED_CACHE = false; /** * Clean an previous error log(if such exists) for the script being loaded before trying to load.<BR> * Apply only when executing script from files.<BR> */ private final boolean PURGE_ERROR_LOG = true; private AionScriptEngineManager() { ScriptEngineManager scriptEngineManager = new ScriptEngineManager(); List<ScriptEngineFactory> factories = scriptEngineManager.getEngineFactories(); if (USE_COMPILED_CACHE) { _cache = loadCompiledScriptCache(); } else { _cache = null; } log.info("Initializing Script Engine Manager"); for (ScriptEngineFactory factory : factories) { try { log.info("Script Engine: " + factory.getEngineName() + " " + factory.getEngineVersion() + " - Language: " + factory.getLanguageName() + " " + factory.getLanguageVersion()); ScriptEngine engine = factory.getScriptEngine(); for (String name : factory.getNames()) { if (_nameEngines.containsKey(name)) throw new IllegalStateException("Multiple script engines for the same name!"); _nameEngines.put(name, engine); } for (String ext : factory.getExtensions()) { if (_extEngines.containsKey(ext)) throw new IllegalStateException("Multiple script engines for the same extension!"); _extEngines.put(ext, engine); } } catch (Exception e) { log.warn("Failed initializing factory.", e); } } } private ScriptEngine getEngineByName(String name) { return _nameEngines.get(name); } private ScriptEngine getEngineByExtension(String ext) { return _extEngines.get(ext); } public void executeScriptList(File list) throws IOException { if (list.isFile()) { LineNumberReader lnr = new LineNumberReader(new FileReader(list)); String line; File file; while ((line = lnr.readLine()) != null) { String[] parts = line.trim().split("#"); if (parts.length > 0 && !parts[0].startsWith("#") && parts[0].length() > 0) { line = parts[0]; if (line.endsWith("/**")) { line = line.substring(0, line.length() - 3); } else if (line.endsWith("/*")) { line = line.substring(0, line.length() - 2); } file = new File(SCRIPT_FOLDER, line); if (file.isDirectory() && parts[0].endsWith("/**")) { this.executeAllScriptsInDirectory(file, true, 32); } else if (file.isDirectory() && parts[0].endsWith("/*")) { this.executeAllScriptsInDirectory(file); } else if (file.isFile()) { try { this.executeScript(file); } catch (ScriptException e) { reportScriptFileError(file, e); } } else { log.warn("Failed loading: (" + file.getCanonicalPath() + ") @ " + list.getName() + ":" + lnr.getLineNumber() + " - Reason: doesnt exists or is not a file."); } } } lnr.close(); } else { throw new IllegalArgumentException( "Argument must be an file containing a list of scripts to be loaded"); } } public void executeAllScriptsInDirectory(File dir) { this.executeAllScriptsInDirectory(dir, false, 0); } public void executeAllScriptsInDirectory(File dir, boolean recurseDown, int maxDepth) { this.executeAllScriptsInDirectory(dir, recurseDown, maxDepth, 0); } private void executeAllScriptsInDirectory(File dir, boolean recurseDown, int maxDepth, int currentDepth) { if (dir.isDirectory()) { for (File file : dir.listFiles()) { if (file.isDirectory() && recurseDown && maxDepth > currentDepth) { if (VERBOSE_LOADING) { log.info("Entering folder: " + file.getName()); } this.executeAllScriptsInDirectory(file, recurseDown, maxDepth, currentDepth + 1); } else if (file.isFile()) { try { String name = file.getName(); int lastIndex = name.lastIndexOf('.'); String extension; if (lastIndex != -1) { extension = name.substring(lastIndex + 1); ScriptEngine engine = getEngineByExtension(extension); if (engine != null) { this.executeScript(engine, file); } } } catch (FileNotFoundException e) { // should never happen log.error(e.getMessage(), e); } catch (ScriptException e) { reportScriptFileError(file, e); // _log.error(e.getMessage(),e); } } } } else { throw new IllegalArgumentException( "The argument directory either doesnt exists or is not an directory."); } } public CompiledScriptCache getCompiledScriptCache() { return _cache; } public CompiledScriptCache loadCompiledScriptCache() { if (USE_COMPILED_CACHE) { File file = new File(SCRIPT_FOLDER, "CompiledScripts.cache"); if (file.isFile()) { ObjectInputStream ois = null; try { ois = new ObjectInputStream(new FileInputStream(file)); CompiledScriptCache cache = (CompiledScriptCache) ois.readObject(); return cache; } catch (InvalidClassException e) { log.error("Failed loading Compiled Scripts Cache, invalid class (Possibly outdated).", e); } catch (IOException e) { log.error("Failed loading Compiled Scripts Cache from file.", e); } catch (ClassNotFoundException e) { log.error("Failed loading Compiled Scripts Cache, class not found.", e); } finally { IOUtils.closeQuietly(ois); } return new CompiledScriptCache(); } return new CompiledScriptCache(); } return null; } public void executeScript(File file) throws ScriptException, FileNotFoundException { String name = file.getName(); int lastIndex = name.lastIndexOf('.'); String extension; if (lastIndex != -1) { extension = name.substring(lastIndex + 1); } else { throw new ScriptException("Script file (" + name + ") doesnt has an extension that identifies the ScriptEngine to be used."); } ScriptEngine engine = getEngineByExtension(extension); if (engine == null) throw new ScriptException("No engine registered for extension (" + extension + ")"); this.executeScript(engine, file); } public void executeScript(String engineName, File file) throws FileNotFoundException, ScriptException { ScriptEngine engine = getEngineByName(engineName); if (engine == null) throw new ScriptException("No engine registered with name (" + engineName + ")"); this.executeScript(engine, file); } public void executeScript(ScriptEngine engine, File file) throws FileNotFoundException, ScriptException { BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream(file))); if (VERBOSE_LOADING) { log.info("Loading Script: " + file.getAbsolutePath()); } if (PURGE_ERROR_LOG) { String name = file.getAbsolutePath() + ".error.log"; File errorLog = new File(name); if (errorLog.isFile()) { errorLog.delete(); } } if (engine instanceof Compilable && ATTEMPT_COMPILATION) { ScriptContext context = new SimpleScriptContext(); context.setAttribute("mainClass", getClassForFile(file).replace('/', '.').replace('\\', '.'), ScriptContext.ENGINE_SCOPE); context.setAttribute(ScriptEngine.FILENAME, file.getName(), ScriptContext.ENGINE_SCOPE); context.setAttribute("classpath", SCRIPT_FOLDER.getAbsolutePath(), ScriptContext.ENGINE_SCOPE); context.setAttribute("sourcepath", SCRIPT_FOLDER.getAbsolutePath(), ScriptContext.ENGINE_SCOPE); context.setAttribute("parentLoader", ClassLoader.getSystemClassLoader(), ScriptContext.ENGINE_SCOPE); setCurrentLoadingScript(file); ScriptContext ctx = engine.getContext(); try { engine.setContext(context); if (USE_COMPILED_CACHE) { CompiledScript cs = _cache.loadCompiledScript(engine, file); cs.eval(context); } else { Compilable eng = (Compilable) engine; CompiledScript cs = eng.compile(reader); cs.eval(context); } } finally { engine.setContext(ctx); setCurrentLoadingScript(null); context.removeAttribute(ScriptEngine.FILENAME, ScriptContext.ENGINE_SCOPE); context.removeAttribute("mainClass", ScriptContext.ENGINE_SCOPE); context.removeAttribute("parentLoader", ScriptContext.ENGINE_SCOPE); } } else { ScriptContext context = new SimpleScriptContext(); context.setAttribute("mainClass", getClassForFile(file).replace('/', '.').replace('\\', '.'), ScriptContext.ENGINE_SCOPE); context.setAttribute(ScriptEngine.FILENAME, file.getName(), ScriptContext.ENGINE_SCOPE); context.setAttribute("classpath", SCRIPT_FOLDER.getAbsolutePath(), ScriptContext.ENGINE_SCOPE); context.setAttribute("sourcepath", SCRIPT_FOLDER.getAbsolutePath(), ScriptContext.ENGINE_SCOPE); context.setAttribute("parentLoader", ClassLoader.getSystemClassLoader(), ScriptContext.ENGINE_SCOPE); setCurrentLoadingScript(file); try { engine.eval(reader, context); } finally { setCurrentLoadingScript(null); engine.getContext().removeAttribute(ScriptEngine.FILENAME, ScriptContext.ENGINE_SCOPE); engine.getContext().removeAttribute("mainClass", ScriptContext.ENGINE_SCOPE); engine.getContext().removeAttribute("parentLoader", ScriptContext.ENGINE_SCOPE); } } } public static String getClassForFile(File script) { String path = script.getAbsolutePath(); String scpPath = SCRIPT_FOLDER.getAbsolutePath(); if (path.startsWith(scpPath)) { int idx = path.lastIndexOf('.'); return path.substring(scpPath.length() + 1, idx); } return null; } public ScriptContext getScriptContext(ScriptEngine engine) { return engine.getContext(); } public ScriptContext getScriptContext(String engineName) { ScriptEngine engine = getEngineByName(engineName); if (engine == null) throw new IllegalStateException("No engine registered with name (" + engineName + ")"); return this.getScriptContext(engine); } public Object eval(ScriptEngine engine, String script, ScriptContext context) throws ScriptException { if (engine instanceof Compilable && ATTEMPT_COMPILATION) { Compilable eng = (Compilable) engine; CompiledScript cs = eng.compile(script); return context != null ? cs.eval(context) : cs.eval(); } return context != null ? engine.eval(script, context) : engine.eval(script); } public Object eval(String engineName, String script) throws ScriptException { return this.eval(engineName, script, null); } public Object eval(String engineName, String script, ScriptContext context) throws ScriptException { ScriptEngine engine = getEngineByName(engineName); if (engine == null) throw new ScriptException("No engine registered with name (" + engineName + ")"); return this.eval(engine, script, context); } public Object eval(ScriptEngine engine, String script) throws ScriptException { return this.eval(engine, script, null); } public void reportScriptFileError(File script, ScriptException e) { log.warn("Failed executing script: " + script.getPath() + "."); final StringWriter sw = new StringWriter(); final PrintWriter pw = new PrintWriter(sw); pw.println("Error on: " + script.getAbsolutePath()); pw.println("Line: " + e.getLineNumber() + " - Column: " + e.getColumnNumber()); pw.println(); e.printStackTrace(pw); pw.close(); final String report = sw.toString(); FileOutputStream fos = null; try { String fileName = script.getName() + ".error.log"; fos = new FileOutputStream(new File(script.getParent(), fileName)); fos.write(report.getBytes()); log.warn("See " + fileName + " for details."); } catch (IOException ioe) { log.warn("Additionally failed when trying to write an error report on script directory.", ioe); log.info(report); } finally { IOUtils.closeQuietly(fos); } } public void registerScriptManager(ScriptManager<?> manager) { _scriptManagers.add(manager); } public void removeScriptManager(ScriptManager<?> manager) { _scriptManagers.remove(manager); } public List<ScriptManager<?>> getScriptManagers() { return _scriptManagers; } /** * @param currentLoadingScript * The currentLoadingScript to set. */ protected void setCurrentLoadingScript(File currentLoadingScript) { _currentLoadingScript = currentLoadingScript; } /** * @return Returns the currentLoadingScript. */ protected File getCurrentLoadingScript() { return _currentLoadingScript; } @SuppressWarnings("synthetic-access") private static class SingletonHolder { protected static final AionScriptEngineManager _instance = new AionScriptEngineManager(); } }