提交 63a7ba24 编写于 作者: M martin

4245470: algorithm of java.lang.Byte.hashCode() is not specified

Summary: Specify some hashCode methods are equivalent to intValue
Reviewed-by: darcy
上级 9edf4f07
......@@ -378,7 +378,10 @@ public final class Byte extends Number implements Comparable<Byte> {
}
/**
* Returns a hash code for this {@code Byte}.
* Returns a hash code for this {@code Byte}; equal to the result
* of invoking {@code intValue()}.
*
* @return a hash code value for this {@code Byte}
*/
public int hashCode() {
return (int)value;
......
......@@ -2612,8 +2612,10 @@ class Character extends Object implements java.io.Serializable, Comparable<Chara
}
/**
* Returns a hash code for this <code>Character</code>.
* @return a hash code value for this object.
* Returns a hash code for this {@code Character}; equal to the result
* of invoking {@code charValue()}.
*
* @return a hash code value for this {@code Character}
*/
public int hashCode() {
return (int)value;
......
......@@ -383,7 +383,10 @@ public final class Short extends Number implements Comparable<Short> {
}
/**
* Returns a hash code for this {@code Short}.
* Returns a hash code for this {@code Short}; equal to the result
* of invoking {@code intValue()}.
*
* @return a hash code value for this {@code Short}
*/
public int hashCode() {
return (int)value;
......
/*
* Copyright 2009 Google, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*/
/*
* @test
* @bug 4245470
* @summary Test the primitive wrappers hashCode()
*/
import java.util.Random;
public class HashCode {
final Random rnd = new Random();
void test(String args[]) throws Exception {
int[] ints = {
Integer.MIN_VALUE,
Short.MIN_VALUE,
Character.MIN_VALUE,
Byte.MIN_VALUE,
-1, 0, 1,
Byte.MAX_VALUE,
Character.MAX_VALUE,
Short.MAX_VALUE,
Integer.MAX_VALUE,
rnd.nextInt(),
};
for (int x : ints) {
check( new Long(x).hashCode() == (int)((long)x ^ (long)x>>>32));
check(Long.valueOf(x).hashCode() == (int)((long)x ^ (long)x>>>32));
check( new Integer(x).hashCode() == x);
check(Integer.valueOf(x).hashCode() == x);
check( new Short((short)x).hashCode() == (short) x);
check(Short.valueOf((short)x).hashCode() == (short) x);
check( new Character((char) x).hashCode() == (char) x);
check(Character.valueOf((char) x).hashCode() == (char) x);
check( new Byte((byte) x).hashCode() == (byte) x);
check(Byte.valueOf((byte) x).hashCode() == (byte) x);
}
}
//--------------------- Infrastructure ---------------------------
volatile int passed = 0, failed = 0;
void pass() {passed++;}
void fail() {failed++; Thread.dumpStack();}
void fail(String msg) {System.err.println(msg); fail();}
void unexpected(Throwable t) {failed++; t.printStackTrace();}
void check(boolean cond) {if (cond) pass(); else fail();}
void equal(Object x, Object y) {
if (x == null ? y == null : x.equals(y)) pass();
else fail(x + " not equal to " + y);}
public static void main(String[] args) throws Throwable {
new HashCode().instanceMain(args);}
public void instanceMain(String[] args) throws Throwable {
try {test(args);} catch (Throwable t) {unexpected(t);}
System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
if (failed > 0) throw new AssertionError("Some tests failed");}
}
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