package com.airhacks.enhydrator.transform; /* * #%L * enhydrator * %% * Copyright (C) 2014 Adam Bien * %% * 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. * #L% */ import com.airhacks.enhydrator.in.Row; import java.util.Map; import java.util.function.Consumer; import javax.script.Bindings; import javax.script.ScriptEngine; import javax.script.ScriptEngineManager; import javax.script.ScriptException; /** * * @author airhacks.com */ public class Expression { private final ScriptEngineManager manager; private final ScriptEngine engine; private final Map<String, Object> scriptEngineBindings; private Consumer<String> expressionListener; public Expression() { this(l -> { }, null); } public Expression(Consumer<String> expressionListener, Map<String, Object> scriptEngineBindings) { this.expressionListener = expressionListener; this.manager = new ScriptEngineManager(); this.engine = manager.getEngineByName("nashorn"); this.scriptEngineBindings = scriptEngineBindings; } public Row execute(Row input, String expression) { Bindings bindings = ScriptingEnvironmentProvider.create(manager, this.scriptEngineBindings, input); try { this.expressionListener.accept("Executing: " + expression); Object result = this.engine.eval(expression, bindings); this.expressionListener.accept("Got result: " + result); if (!(result instanceof Row)) { return input; } else { return (Row) result; } } catch (ScriptException ex) { throw new IllegalStateException(ex.getMessage(), ex); } } }