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 018package org.apache.commons.jexl3.scripting; 019 020import java.io.BufferedReader; 021import java.io.File; 022import java.io.FileInputStream; 023import java.io.InputStreamReader; 024 025import java.nio.charset.Charset; 026import javax.script.ScriptEngine; 027import javax.script.ScriptException; 028 029/** 030 * Test application for JexlScriptEngine (JSR-223 implementation). 031 * 032 * @since 2.0 033 */ 034public class Main { 035 036 /** 037 * Reads an input. 038 * 039 * @param charset the charset or null for default charset 040 * @param fileName the file name or null for stdin 041 * @return the reader 042 * @throws Exception if anything goes wrong 043 */ 044 static BufferedReader read(final Charset charset, final String fileName) throws Exception { 045 return new BufferedReader( 046 new InputStreamReader( 047 fileName == null 048 ? System.in 049 : new FileInputStream(new File(fileName)), 050 charset == null 051 ? Charset.defaultCharset() 052 : charset)); 053 } 054 055 /** 056 * Test application for JexlScriptEngine (JSR-223 implementation). 057 * 058 * If a single argument is present, it is treated as a file name of a JEXL 059 * script to be evaluated. Any exceptions terminate the application. 060 * 061 * Otherwise, lines are read from standard input and evaluated. 062 * ScriptExceptions are logged, and do not cause the application to exit. 063 * This is done so that interactive testing is easier. 064 * 065 * @param args (optional) file name to evaluate. Stored in the args variable. 066 * 067 * @throws Exception if parsing or IO fail 068 */ 069 public static void main(final String[] args) throws Exception { 070 final JexlScriptEngineFactory fac = new JexlScriptEngineFactory(); 071 final ScriptEngine engine = fac.getScriptEngine(); 072 engine.put("args", args); 073 if (args.length == 1){ 074 final Object value = engine.eval(read(null, args[0])); 075 System.out.println("Return value: "+value); 076 } else { 077 final BufferedReader console = read(null, null); 078 String line; 079 System.out.print("> "); 080 while(null != (line=console.readLine())){ 081 try { 082 final Object value = engine.eval(line); 083 System.out.println("Return value: "+value); 084 } catch (final ScriptException e) { 085 System.out.println(e.getLocalizedMessage()); 086 } 087 System.out.print("> "); 088 } 089 } 090 } 091}