| #// Usage: jjs -scripting javashell.js |
| |
| /* |
| * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * - Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * - Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * - Neither the name of Oracle nor the names of its |
| * contributors may be used to endorse or promote products derived |
| * from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS |
| * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, |
| * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR |
| * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
| * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF |
| * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
| * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
| * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| // Simple Java "shell" with which you can try out |
| // your few liner Java code leaving imports, main etc. |
| // And you can leave even compilation as this script |
| // takes care boilerplate+compile step for you. |
| |
| // Java types used |
| var Arrays = Java.type("java.util.Arrays"); |
| var BufferedReader = Java.type("java.io.BufferedReader"); |
| var FileWriter = Java.type("java.io.FileWriter"); |
| var LocalDateTime = Java.type("java.time.LocalDateTime"); |
| var InputStreamReader = Java.type("java.io.InputStreamReader"); |
| var PrintWriter = Java.type("java.io.PrintWriter"); |
| var ProcessBuilder = Java.type("java.lang.ProcessBuilder"); |
| var System = Java.type("java.lang.System"); |
| |
| // read multiple lines of input from stdin till user |
| // enters an empty line |
| function input(endMarker, prompt) { |
| if (!endMarker) { |
| endMarker = ""; |
| } |
| |
| if (!prompt) { |
| prompt = " >> "; |
| } |
| |
| var str = ""; |
| var reader = new BufferedReader(new InputStreamReader(System.in)); |
| var line; |
| while (true) { |
| System.out.print(prompt); |
| line = reader.readLine(); |
| if (line == null || line == endMarker) { |
| break; |
| } |
| str += line + "\n"; |
| } |
| return str; |
| } |
| |
| // write the string to the given file |
| function writeTo(file, str) { |
| var w = new PrintWriter(new FileWriter(file)); |
| try { |
| w.print(str); |
| } finally { |
| w.close(); |
| } |
| } |
| |
| // generate Java code with user's input |
| // put inside generated main method |
| function generate(className) { |
| var usercode = input(); |
| if (usercode == "") { |
| return false; |
| } |
| |
| var fullcode = <<EOF |
| // userful imports, add more here if you want |
| // more imports. |
| import static java.lang.System.*; |
| import java.io.*; |
| import java.net.*; |
| import java.math.*; |
| import java.nio.file.*; |
| import java.time.*; |
| import java.time.chrono.*; |
| import java.time.format.*; |
| import java.time.temporal.*; |
| import java.time.zone.*; |
| import java.util.*; |
| import java.util.concurrent.*; |
| import java.util.function.*; |
| import java.util.stream.*; |
| |
| public class ${className} { |
| public static void main(String[] args) throws Exception { |
| ${usercode} |
| } |
| } |
| EOF |
| |
| writeTo("${className}.java", fullcode); |
| return true; |
| } |
| |
| // execute code command |
| function exec(args) { |
| // build child process and start it! |
| new ProcessBuilder(Arrays.asList(args.split(' '))) |
| .inheritIO() |
| .start() |
| .waitFor(); |
| } |
| |
| // generate unique name |
| function uniqueName() { |
| var now = LocalDateTime.now().toString(); |
| // replace unsafe chars with '_' |
| return "JavaShell" + now.replace(/-|:|\./g, '_'); |
| } |
| |
| // read-compile-run loop |
| while(true) { |
| var className = uniqueName(); |
| if (generate(className)) { |
| exec("javac ${className}.java"); |
| exec("java ${className}"); |
| } else { |
| break; |
| } |
| } |