1 /*
   2  * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  *
   8  *   - Redistributions of source code must retain the above copyright
   9  *     notice, this list of conditions and the following disclaimer.
  10  *
  11  *   - Redistributions in binary form must reproduce the above copyright
  12  *     notice, this list of conditions and the following disclaimer in the
  13  *     documentation and/or other materials provided with the distribution.
  14  *
  15  *   - Neither the name of Oracle nor the names of its
  16  *     contributors may be used to endorse or promote products derived
  17  *     from this software without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
  20  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  21  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
  23  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  24  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  25  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  26  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  27  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  28  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  29  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30  */
  31 
  32 /* This sample implements Java-like try..with..resource construct for nashorn */
  33 
  34 if (arguments.length == 0) {
  35     print("Usage: jjs try_with_resource.js -- <file name>");
  36     exit(1);
  37 }
  38 
  39 // Object.create accepts prototype and properties object
  40 function With(res) {
  41    return Object.create(With.prototype,
  42        { res: { value: res } });
  43 }
  44 
  45 // reserved words can be used as property names - for example "try"
  46 With.prototype.try = function(callback) {
  47      try {
  48          callback();
  49      } finally {
  50          this.res.close();
  51      }
  52 }
  53 
  54 var BufferedReader = Java.type("java.io.BufferedReader");
  55 var FileReader = Java.type("java.io.FileReader");
  56 
  57 var r = new BufferedReader(new FileReader(arguments[0]));
  58 
  59 // Java-like try..with..resource
  60 With(r).try(function() {
  61     var s;
  62     while ((s = r.readLine()) != null) {
  63         print(s);
  64     }
  65 })