    001    /*
    002     * Licensed to the Apache Software Foundation (ASF) under one or more
    003     * contributor license agreements.  See the NOTICE file distributed with
    004     * this work for additional information regarding copyright ownership.
    005     * The ASF licenses this file to You under the Apache License, Version 2.0
    006     * (the "License"); you may not use this file except in compliance with
    007     * the License.  You may obtain a copy of the License at
    008     *
    009     *      http://www.apache.org/licenses/LICENSE-2.0
    010     *
    011     * Unless required by applicable law or agreed to in writing, software
    012     * distributed under the License is distributed on an "AS IS" BASIS,
    013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014     * See the License for the specific language governing permissions and
    015     * limitations under the License.
    016     */
    017
    018    package org.apache.commons.jexl2.scripting;
    019
    020    import java.io.BufferedReader;
    021    import java.io.FileReader;
    022    import java.io.InputStreamReader;
    023
    024    import javax.script.ScriptEngine;
    025    import javax.script.ScriptException;
    026
    027    /**
    028     * Test application for JexlScriptEngine (JSR-223 implementation).
    029     * @since 2.0
    030     */
    031    public class Main {
    032
    033        /**
    034         * Test application for JexlScriptEngine (JSR-223 implementation).
    035         *
    036         * If a single argument is present, it is treated as a filename of a JEXL
    037         * script to be evaluated. Any exceptions terminate the application.
    038         *
    039         * Otherwise, lines are read from standard input and evaluated.
    040         * ScriptExceptions are logged, and do not cause the application to exit.
    041         * This is done so that interactive testing is easier.
    042         *
    043         * @param args (optional) filename to evaluate. Stored in the args variable.
    044         *
    045         * @throws Exception if parsing or IO fail
    046         */
    047        public static void main(String[] args) throws Exception {
    048            JexlScriptEngineFactory fac = new JexlScriptEngineFactory();
    049            ScriptEngine engine = fac.getScriptEngine();
    050            engine.put("args", args);
    051            if (args.length == 1){
    052                Object value = engine.eval(new FileReader(args[0]));
    053                System.out.println("Return value: "+value);
    054            } else {
    055                BufferedReader console = new BufferedReader(new InputStreamReader(System.in));
    056                String line;
    057                System.out.print("> ");
    058                while(null != (line=console.readLine())){
    059                    try {
    060                        Object value = engine.eval(line);
    061                        System.out.println("Return value: "+value);
    062                    } catch (ScriptException e) {
    063                        System.out.println(e.getLocalizedMessage());
    064                    }
    065                    System.out.print("> ");
    066                }
    067            }
    068        }
    069    }