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/*
* 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;
}
}
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