1 /*
   2  * Copyright 2010 Google Inc.  All Rights Reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 /*
  25  * @test
  26  * @bug 6952330
  27  * @summary Test StringBuffer/StringBuilder capacity handling.
  28  */
  29 
  30 import java.util.Random;
  31 
  32 public class Capacity {
  33     void test(String[] args) throws Throwable {
  34         Random rnd = new Random();
  35         int[] sizes = { 0, 1, rnd.nextInt(10), rnd.nextInt(1000) };
  36         for (int size : sizes) {
  37             equal(16, new StringBuffer().capacity());
  38             equal(16, new StringBuilder().capacity());
  39             StringBuffer buff = new StringBuffer(size);
  40             StringBuilder bild = new StringBuilder(size);
  41             equal(size, buff.capacity());
  42             equal(size, bild.capacity());
  43             buff.ensureCapacity(size);
  44             bild.ensureCapacity(size);
  45             equal(size, buff.capacity());
  46             equal(size, bild.capacity());
  47             buff.ensureCapacity(size+1);
  48             bild.ensureCapacity(size+1);
  49             equal(size*2+2, buff.capacity());
  50             equal(size*2+2, bild.capacity());
  51             size = buff.capacity();
  52             buff.ensureCapacity(size*2+1);
  53             bild.ensureCapacity(size*2+1);
  54             equal(size*2+2, buff.capacity());
  55             equal(size*2+2, bild.capacity());
  56             size = buff.capacity();
  57             int newSize = size * 2 + 3;
  58             buff.ensureCapacity(newSize);
  59             bild.ensureCapacity(newSize);
  60             equal(newSize, buff.capacity());
  61             equal(newSize, bild.capacity());
  62             buff.ensureCapacity(0);
  63             bild.ensureCapacity(0);
  64             equal(newSize, buff.capacity());
  65             equal(newSize, bild.capacity());
  66         }
  67     }
  68 
  69     //--------------------- Infrastructure ---------------------------
  70     volatile int passed = 0, failed = 0;
  71     void pass() {passed++;}
  72     void fail() {failed++; Thread.dumpStack();}
  73     void fail(String msg) {System.err.println(msg); fail();}
  74     void unexpected(Throwable t) {failed++; t.printStackTrace();}
  75     void check(boolean cond) {if (cond) pass(); else fail();}
  76     void equal(Object x, Object y) {
  77         if (x == null ? y == null : x.equals(y)) pass();
  78         else fail(x + " not equal to " + y);}
  79     public static void main(String[] args) throws Throwable {
  80         new Capacity().instanceMain(args);}
  81     public void instanceMain(String[] args) throws Throwable {
  82         try {test(args);} catch (Throwable t) {unexpected(t);}
  83         System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
  84         if (failed > 0) throw new AssertionError("Some tests failed");}
  85 }