Java tutorial
/* Copyright 2007, Lucid Technics, LLC. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. */ package com.lucidtechnics.blackboard.util; import java.io.Reader; import java.io.InputStream; import java.io.InputStreamReader; import java.io.StringReader; import java.util.Set; import java.util.HashSet; import java.util.Map; import java.util.HashMap; import javax.script.ScriptContext; import javax.script.ScriptEngine; import javax.script.CompiledScript; import javax.script.ScriptEngineFactory; import javax.script.ScriptException; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import com.lucidtechnics.blackboard.util.PropertyUtil; public class Jsr223ScriptingUtil implements ScriptingUtil { static { Map<String, String> tempExtensionToEngineMap = new HashMap<String, String>(); tempExtensionToEngineMap.put("bsh", "bsh.engine.BshScriptEngineFactory"); tempExtensionToEngineMap.put("java", "com.sun.script.groovy.GroovyScriptEngineFactory"); tempExtensionToEngineMap.put("rb", "com.sun.script.jruby.JRubyScriptEngineFactory"); tempExtensionToEngineMap.put("ruby", "com.sun.script.jruby.JRubyScriptEngineFactory"); tempExtensionToEngineMap.put("py", "com.sun.script.jython.JythonScriptEngineFactory"); tempExtensionToEngineMap.put("python", "com.sun.script.jython.JythonScriptEngineFactory"); tempExtensionToEngineMap.put("gr", "com.sun.script.groovy.GroovyScriptEngineFactory"); tempExtensionToEngineMap.put("groovy", "com.sun.script.groovy.GroovyScriptEngineFactory"); extensionToEngineMap = tempExtensionToEngineMap; } private static Log log = LogFactory.getLog(Jsr223ScriptingUtil.class); private static Map<String, String> extensionToEngineMap; private static final Map<String, CompiledScript> scriptResourceMap = new HashMap<String, CompiledScript>(); private ScriptEngine scriptEngine; private Map<String, Object> bindingsMap; private ScriptEngine getScriptEngine() { return scriptEngine; } private Map<String, CompiledScript> getScriptResourceMap() { return scriptResourceMap; } private Map<String, Object> getBindingsMap() { return bindingsMap; } private void setScriptEngine(ScriptEngine _scriptEngine) { scriptEngine = _scriptEngine; } public void setBindingsMap(Map<String, Object> _bindingsMap) { bindingsMap = _bindingsMap; } public Jsr223ScriptingUtil(String _extension) { String factoryName = null; try { factoryName = extensionToEngineMap.get(_extension); if (factoryName == null) { throw new RuntimeException("Scripting not supported for files ending in: " + _extension); } ScriptEngineFactory factory = (ScriptEngineFactory) Class.forName(factoryName).newInstance(); ScriptEngine scriptEngine = factory.getScriptEngine(); setScriptEngine(scriptEngine); setBindingsMap(new HashMap<String, Object>()); } catch (ClassNotFoundException t) { throw new RuntimeException("Please make sure the appropriate jar files for factory: " + factoryName + " are place in the lib/engines directory in order to run scripts of extension: " + _extension); } catch (Throwable t) { throw new RuntimeException(t); } } public CompiledScript compileScript(String _scriptResource) { Reader reader = null; try { if (getScriptResourceMap().containsKey(_scriptResource) == false && getScriptEngine() instanceof javax.script.Compilable) { reader = new InputStreamReader(findScript(_scriptResource)); CompiledScript script = ((javax.script.Compilable) getScriptEngine()).compile(reader); synchronized (getScriptResourceMap()) { getScriptResourceMap().put(_scriptResource, script); } } } catch (Throwable t) { throw new RuntimeException(t); } finally { if (reader != null) { try { reader.close(); } catch (Throwable t) { } } } return getScriptResourceMap().get(_scriptResource); } public static boolean hasScriptingEngine(String _extension) { return (extensionToEngineMap.containsKey(_extension) == true); } public void bind(String _name, Object _value) { getBindingsMap().put(_name, _value); } public void loadScript(String _scriptResource) { executeScript(_scriptResource); } private InputStream findScript(String _scriptResource) { String rapidDeploy = "no"; InputStream inputStream = null; try { if (log.isDebugEnabled() == true) { log.debug("Attempting to load script: " + _scriptResource); } java.io.File file = new java.io.File(_scriptResource); if (file.exists() == true) { inputStream = new java.io.FileInputStream(file); } } catch (Throwable t) { throw new RuntimeException(t); } if (inputStream == null) { throw new RuntimeException( "Unable to find script file. Make sure that this: " + _scriptResource + " exists."); } return inputStream; } public Object executeScript(String _scriptResource) { ScriptContext scriptContext = getScriptEngine().getContext(); Object result = null; try { for (String key : getBindingsMap().keySet()) { scriptContext.setAttribute(key, getBindingsMap().get(key), ScriptContext.ENGINE_SCOPE); } CompiledScript script = compileScript(_scriptResource); if (script != null) { result = script.eval(scriptContext); } else { result = getScriptEngine().eval(new InputStreamReader(findScript(_scriptResource)), scriptContext); } } catch (Throwable t) { throw new RuntimeException( "Unable to execute script: " + _scriptResource + " for this reason: " + t.toString(), t); } return result; } public Object executeScript(String[] _scriptResources) { ScriptContext scriptContext = getScriptEngine().getContext(); Object result = null; int i = 0; try { for (String key : getBindingsMap().keySet()) { scriptContext.setAttribute(key, getBindingsMap().get(key), ScriptContext.ENGINE_SCOPE); } for (i = 0; i < _scriptResources.length; i++) { CompiledScript script = compileScript(_scriptResources[i]); if (script != null) { result = script.eval(scriptContext); } else { result = getScriptEngine().eval(new InputStreamReader(findScript(_scriptResources[i])), scriptContext); } } } catch (Throwable t) { throw new RuntimeException( "Unable to execute script: " + _scriptResources[i] + " for this reason: " + t.toString(), t); } return result; } public Object execute(String _script) { Object result = null; if (_script == null) { throw new RuntimeException("Unable to execute null script"); } ScriptContext scriptContext = getScriptEngine().getContext(); try { result = getScriptEngine().eval(_script, scriptContext); } catch (Throwable t) { throw new RuntimeException("Unable to execute script: " + _script + " for this reason: " + t.toString(), t); } return result; } }