| /* |
| * Copyright (c) 2003, 2004, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| /* @test |
| * @bug 4546734 5007612 |
| * @summary Test StringBuffer.trimToSize |
| * @key randomness |
| */ |
| |
| import java.util.Random; |
| |
| public class Trim { |
| private static Random generator = new Random(); |
| |
| public static void main(String[] args) throws Exception { |
| bash(); |
| //capacityCheck(); |
| } |
| |
| // Make sure trimToSize is safe to use; it should never cause an |
| // exception or mutation |
| private static void bash() throws Exception { |
| for (int i=0; i<1000; i++) { |
| StringBuffer sb1 = generateTestBuffer(0, 100); |
| StringBuffer sb2 = new StringBuffer(sb1); |
| sb1.trimToSize(); |
| if (!sb1.toString().equals(sb2.toString())) |
| throw new RuntimeException( |
| "trim mutated stringbuffer contents"); |
| // Append a random sb |
| StringBuffer sb3 = generateTestBuffer(0, 100); |
| sb1.append(sb3); |
| sb2.append(sb3); |
| if (generator.nextInt(2) == 0) |
| sb1.trimToSize(); |
| else |
| sb2.trimToSize(); |
| if (!sb1.toString().equals(sb2.toString())) |
| throw new RuntimeException( |
| "trim mutated stringbuffer contents"); |
| // Append sb with lots of extra space |
| sb3 = new StringBuffer(100); |
| sb3.append("a"); |
| sb1.append(sb3); |
| sb2.append(sb3); |
| if (generator.nextInt(2) == 0) |
| sb1.trimToSize(); |
| else |
| sb2.trimToSize(); |
| if (!sb1.toString().equals(sb2.toString())) |
| throw new RuntimeException( |
| "trim mutated stringbuffer contents"); |
| } |
| } |
| |
| // This test gives some assurance that trimToSize is working but |
| // it should not be part of an automated run, and a failure here |
| // is not against spec; this method is provided simply to be run |
| // by hand and assure the engineer that it is working. The test |
| // may stop working at some time in the future depending on |
| // how String and StringBuffer are implemented because it depends |
| // upon the capacity method. |
| private static void capacityCheck() { |
| for (int i=0; i<100; i++) { |
| int sizeNeeded = generator.nextInt(1000)+1; |
| int sizeExtra = generator.nextInt(100) + 1; |
| StringBuffer sb = new StringBuffer(sizeNeeded + sizeExtra); |
| StringBuffer sb2 = generateTestBuffer(sizeNeeded, sizeNeeded); |
| if (sb2.length() != sizeNeeded) |
| throw new RuntimeException("sb generated incorrectly"); |
| sb.append(sb2); |
| int oldCapacity = sb.capacity(); |
| sb.trimToSize(); |
| int newCapacity = sb.capacity(); |
| if (oldCapacity == newCapacity) |
| throw new RuntimeException("trim failed"); |
| } |
| } |
| |
| private static int getRandomIndex(int constraint1, int constraint2) { |
| int range = constraint2 - constraint1; |
| if (range <= 0) |
| return constraint1; |
| int x = generator.nextInt(range); |
| return constraint1 + x; |
| } |
| |
| private static StringBuffer generateTestBuffer(int min, int max) { |
| StringBuffer aNewStringBuffer = new StringBuffer(); |
| int aNewLength = getRandomIndex(min, max); |
| for(int y=0; y<aNewLength; y++) { |
| int achar = generator.nextInt(30)+30; |
| char test = (char)(achar); |
| aNewStringBuffer.append(test); |
| } |
| return aNewStringBuffer; |
| } |
| |
| } |