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.io.PrintStream; 026import java.nio.charset.Charset; 027import javax.script.ScriptEngine; 028import javax.script.ScriptException; 029 030/** 031 * Test application for JexlScriptEngine (JSR-223 implementation). 032 * 033 * @since 2.0 034 */ 035public class Main { 036 037 /** 038 * Reads an input. 039 * 040 * @param charset the charset or null for default charset 041 * @param fileName the file name or null for stdin 042 * @return the reader 043 * @throws Exception if anything goes wrong 044 */ 045 static BufferedReader read(final Charset charset, final String fileName) throws Exception { 046 return new BufferedReader( 047 new InputStreamReader( 048 fileName == null 049 ? System.in 050 : new FileInputStream(new File(fileName)), 051 charset == null 052 ? Charset.defaultCharset() 053 : charset)); 054 } 055 056 /** 057 * Test application for JexlScriptEngine (JSR-223 implementation). 058 * 059 * If a single argument is present, it is treated as a file name of a JEXL 060 * script to be evaluated. Any exceptions terminate the application. 061 * 062 * Otherwise, lines are read from standard input and evaluated. 063 * ScriptExceptions are logged, and do not cause the application to exit. 064 * This is done so that interactive testing is easier. 065 * 066 * @param args (optional) file name to evaluate. Stored in the args variable. 067 * 068 * @throws Exception if parsing or IO fail 069 */ 070 public static void main(final String[] args) throws Exception { 071 final JexlScriptEngineFactory fac = new JexlScriptEngineFactory(); 072 final ScriptEngine engine = fac.getScriptEngine(); 073 final PrintStream out = System.out; 074 engine.put("args", args); 075 if (args.length == 1){ 076 final Object value = engine.eval(read(null, args[0])); 077 out.println("Return value: "+value); 078 } else { 079 final BufferedReader console = read(null, null); 080 String line; 081 System.out.print("> "); 082 while(null != (line=console.readLine())){ 083 try { 084 final Object value = engine.eval(line); 085 out.println("Return value: "+value); 086 } catch (final ScriptException e) { 087 out.println(e.getLocalizedMessage()); 088 } 089 out.print("> "); 090 } 091 } 092 } 093}