Java tutorial
/* * ************************************************************************************* * Copyright (C) 2008 EsperTech, Inc. All rights reserved. * * http://esper.codehaus.org * * http://www.espertech.com * * ---------------------------------------------------------------------------------- * * The software in this package is published under the terms of the GPL license * * a copy of which has been included with this distribution in the license.txt file. * * ************************************************************************************* */ package com.espertech.esper.epl.script; import com.espertech.esper.client.EPException; import com.espertech.esper.client.EventBean; import com.espertech.esper.epl.expression.ExprEvaluator; import com.espertech.esper.epl.expression.ExprEvaluatorContext; import com.espertech.esper.epl.script.mvel.MVELInvoker; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import java.lang.reflect.InvocationTargetException; import java.util.HashMap; import java.util.Map; public class ExprNodeScriptEvalMVEL extends ExprNodeScriptEvalBase { private static final Log log = LogFactory.getLog(ExprNodeScriptEvalMVEL.class); private final Object executable; public ExprNodeScriptEvalMVEL(String scriptName, String statementName, String[] names, ExprEvaluator[] parameters, Class returnType, Object executable) { super(scriptName, statementName, names, parameters, returnType); this.executable = executable; } public Object evaluate(EventBean[] eventsPerStream, boolean isNewData, ExprEvaluatorContext context) { Map<String, Object> paramsList = new HashMap<String, Object>(); for (int i = 0; i < names.length; i++) { paramsList.put(names[i], parameters[i].evaluate(eventsPerStream, isNewData, context)); } paramsList.put(ExprNodeScript.CONTEXT_BINDING_NAME, context.getAgentInstanceScriptContext()); try { Object result = MVELInvoker.executeExpression(executable, paramsList); if (coercer != null) { return coercer.coerceBoxed((Number) result); } return result; } catch (InvocationTargetException ex) { Throwable mvelException = ex.getCause(); String message = "Unexpected exception executing script '" + scriptName + "' for statement '" + statementName + "' : " + mvelException.getMessage(); log.error(message, mvelException); throw new EPException(message, ex); } } }