Java tutorial
/******************************************************************************* * (c) Copyright 2014 Hewlett-Packard Development Company, L.P. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Apache License v2.0 which accompany this distribution. * * The Apache License is available at * http://www.apache.org/licenses/LICENSE-2.0 * *******************************************************************************/ package org.openscore.lang.runtime.bindings; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Component; import javax.script.ScriptContext; import javax.script.ScriptEngine; import javax.script.ScriptException; import javax.script.SimpleScriptContext; import java.io.Serializable; import java.util.Map; /** * @author stoneo * @since 06/11/2014 * @version $Id$ */ @Component public class ScriptEvaluator { private static final String TRUE = "true"; private static final String FALSE = "false"; @Autowired private ScriptEngine engine; public Serializable evalExpr(String expr, Map<String, ? extends Serializable> context) { ScriptContext scriptContext = new SimpleScriptContext(); for (Map.Entry<String, ? extends Serializable> entry : context.entrySet()) { scriptContext.setAttribute(entry.getKey(), entry.getValue(), ScriptContext.ENGINE_SCOPE); } if (scriptContext.getAttribute(TRUE) == null) scriptContext.setAttribute(TRUE, Boolean.TRUE, ScriptContext.ENGINE_SCOPE); if (scriptContext.getAttribute(FALSE) == null) scriptContext.setAttribute(FALSE, Boolean.FALSE, ScriptContext.ENGINE_SCOPE); try { return (Serializable) engine.eval(expr, scriptContext); } catch (ScriptException e) { ScriptException scriptException = new ScriptException(e); throw new RuntimeException("Error in running script expression or variable reference, for expression: '" + expr + "', Script exception is: \n" + scriptException.getMessage(), scriptException); } } }