Java tutorial
/* * ProActive Parallel Suite(TM): * The Open Source library for parallel and distributed * Workflows & Scheduling, Orchestration, Cloud Automation * and Big Data Analysis on Enterprise Grids & Clouds. * * Copyright (c) 2007 - 2017 ActiveEon * Contact: contact@activeeon.com * * This library is free software: you can redistribute it and/or * modify it under the terms of the GNU Affero General Public License * as published by the Free Software Foundation: version 3 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 Affero General Public License for more details. * * You should have received a copy of the GNU Affero General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. * * If needed, contact us to obtain a release under GPL Version 2 or 3 * or a different license than the AGPL. */ package org.ow2.proactive.scheduler.task.java; import static com.google.common.base.Throwables.getStackTraceAsString; import java.io.IOException; import java.io.PrintStream; import java.io.Reader; import java.io.Serializable; import java.util.Collections; import java.util.List; import java.util.Map; import javax.script.AbstractScriptEngine; import javax.script.Bindings; import javax.script.ScriptContext; import javax.script.ScriptEngineFactory; import javax.script.ScriptException; import javax.script.SimpleBindings; import org.apache.commons.io.IOUtils; import org.apache.commons.io.output.WriterOutputStream; import org.ow2.proactive.scheduler.common.SchedulerConstants; import org.ow2.proactive.scheduler.common.exception.ExecutableCreationException; import org.ow2.proactive.scheduler.common.task.TaskResult; import org.ow2.proactive.scheduler.common.task.executable.JavaExecutable; import org.ow2.proactive.scheduler.common.task.executable.internal.JavaStandaloneExecutableInitializer; import org.ow2.proactive.scheduler.common.task.util.SerializationUtil; import org.ow2.proactive.scheduler.task.exceptions.TaskException; import org.ow2.proactive.scheduler.task.utils.VariablesMap; import org.ow2.proactive.scripting.Script; public class JavaClassScriptEngine extends AbstractScriptEngine { @Override public Object eval(String userExecutableClassName, ScriptContext context) throws ScriptException { try { JavaExecutable javaExecutable = getExecutable(userExecutableClassName); JavaStandaloneExecutableInitializer execInitializer = new JavaStandaloneExecutableInitializer(); PrintStream output = new PrintStream(new WriterOutputStream(context.getWriter()), true); execInitializer.setOutputSink(output); PrintStream error = new PrintStream(new WriterOutputStream(context.getErrorWriter()), true); execInitializer.setErrorSink(error); Map<String, byte[]> propagatedVariables = null; if (context.getAttribute(SchedulerConstants.VARIABLES_BINDING_NAME) != null) { propagatedVariables = SerializationUtil.serializeVariableMap( ((VariablesMap) context.getAttribute(SchedulerConstants.VARIABLES_BINDING_NAME)) .getPropagatedVariables()); execInitializer.setPropagatedVariables(propagatedVariables); } else { execInitializer.setPropagatedVariables(Collections.<String, byte[]>emptyMap()); } if (context.getAttribute(Script.ARGUMENTS_NAME) != null) { execInitializer.setSerializedArguments( (Map<String, byte[]>) ((Serializable[]) context.getAttribute(Script.ARGUMENTS_NAME))[0]); } else { execInitializer.setSerializedArguments(Collections.<String, byte[]>emptyMap()); } if (context.getAttribute(SchedulerConstants.CREDENTIALS_VARIABLE) != null) { execInitializer.setThirdPartyCredentials( (Map<String, String>) context.getAttribute(SchedulerConstants.CREDENTIALS_VARIABLE)); } else { execInitializer.setThirdPartyCredentials(Collections.<String, String>emptyMap()); } if (context.getAttribute(SchedulerConstants.MULTI_NODE_TASK_NODESURL_BINDING_NAME) != null) { List<String> nodesURLs = (List<String>) context .getAttribute(SchedulerConstants.MULTI_NODE_TASK_NODESURL_BINDING_NAME); execInitializer.setNodesURL(nodesURLs); } else { execInitializer.setNodesURL(Collections.<String>emptyList()); } javaExecutable.internalInit(execInitializer, context); Serializable execute = javaExecutable .execute((TaskResult[]) context.getAttribute(SchedulerConstants.RESULTS_VARIABLE)); if (propagatedVariables != null) { ((Map<String, Serializable>) context.getAttribute(SchedulerConstants.VARIABLES_BINDING_NAME)) .putAll(javaExecutable.getVariables()); } output.close(); error.close(); return execute; } catch (Throwable e) { throw new ScriptException(new TaskException(getStackTraceAsString(e), e)); } } public JavaExecutable getExecutable(String userExecutableClassName) throws ExecutableCreationException { try { ClassLoader tcl = Thread.currentThread().getContextClassLoader(); Class<?> userExecutableClass = tcl.loadClass(userExecutableClassName); return (JavaExecutable) userExecutableClass.newInstance(); } catch (ClassNotFoundException e) { throw new ExecutableCreationException( "Unable to instantiate JavaExecutable. " + userExecutableClassName + " class cannot be found", e); } catch (InstantiationException e) { throw new ExecutableCreationException("Unable to instantiate JavaExecutable. " + userExecutableClassName + " might not define no-args constructor", e); } catch (ClassCastException e) { throw new ExecutableCreationException("Unable to instantiate JavaExecutable. " + userExecutableClassName + " might not inherit from org.ow2.proactive.scheduler.common.task.executable.JavaExecutable", e); } catch (Throwable e) { throw new ExecutableCreationException("Unable to instantiate JavaExecutable", e); } } @Override public Object eval(Reader reader, ScriptContext context) throws ScriptException { try { return eval(IOUtils.toString(reader), context); } catch (IOException e) { throw new ScriptException(e); } } @Override public Bindings createBindings() { return new SimpleBindings(); } @Override public ScriptEngineFactory getFactory() { return new JavaClassScriptEngineFactory(); } }