Hello.
Please code review the first-round of java.util.Objects; the patch is below:
http://cr.openjdk.java.net/~darcy/6797535.0/
-Joe
--- old/make/java/java/FILES_java.gmk 2009-10-08 11:04:03.000000000 -0700
+++ new/make/java/java/FILES_java.gmk 2009-10-08 11:04:02.000000000 -0700
@@ -258,6 +258,7 @@
java/util/ServiceConfigurationError.java \
java/util/Timer.java \
java/util/TimerTask.java \
+ java/util/Objects.java \
java/util/UUID.java \
java/util/concurrent/AbstractExecutorService.java \
java/util/concurrent/ArrayBlockingQueue.java \
--- /dev/null 2009-07-06 20:02:10.000000000 -0700
+++ new/src/share/classes/java/util/Objects.java 2009-10-08
11:04:03.000000000 -0700
@@ -0,0 +1,102 @@
+/*
+ * Copyright 2009 Sun Microsystems, 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. Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * 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.
+ */
+
+package java.util;
+
+/**
+ * This class consists of {...@code static} utility methods for operating
+ * on objects. These utilities include {...@code null}-safe or {...@code
+ * null}-tolerant methods for computing the hash code of an object,
+ * returning a string for an object, and comparing two objects.
+ *
+ * @since 1.7
+ */
+public class Objects {
+ private Objects() {
+ throw new AssertionError("No java.util.Objects instances for you!");
+ }
+
+ /**
+ * Returns {...@code true} if the arguments are equal to each other
+ * and {...@code false} otherwise.
+ * Consequently, if both arguments are {...@code null}, {...@code true}
+ * is returned and if exactly one argument is {...@code null}, {...@code
+ * false} is returned. Otherwise, equality is determined by using
+ * the {...@link Object#equals equals} method of the first
+ * argument.
+ *
+ * @return {...@code true} if the arguments are equal to each other
+ * and {...@code false} otherwise
+ * @see Object#equals(Object)
+ */
+ public static boolean equals(Object a, Object b) {
+ return (a == b) || (a != null && a.equals(b));
+ }
+
+ /**
+ * Returns the hash code of a no...@code null} argument and 0 for
+ * a {...@code null} argument.
+ *
+ * @return the hash code of a no...@code null} argument and 0 for
+ * a {...@code null} argument
+ * @see Object#hashCode
+ */
+ public static int hashCode(Object o) {
+ return o != null ? o.hashCode() : 0;
+ }
+
+ /**
+ * Returns the result of calling {...@code toString} for a no...@code
+ * null} argument and {...@code "null"} for a {...@code null} argument.
+ *
+ * @return the result of calling {...@code toString} for a no...@code
+ * null} argument and {...@code "null"} for a {...@code null} argument
+ * @see Object#toString
+ * @see String#valueOf(Object)
+ */
+ public static String toString(Object o) {
+ return String.valueOf(o);
+ }
+
+ /**
+ * Returns 0 if the arguments are identical and {...@code
+ * c.compare(a, b)} otherwise.
+ * Consequently, if both arguments are {...@code null} 0
+ * is returned.
+ *
+ * <p>Note that if one of the arguments is {...@code null}, a {...@code
+ * NullPointerException} may or may not be thrown depending on
+ * what ordering policy, if any, the {...@link Comparator Comparator}
+ * chooses to have for {...@code null} values.
+ *
+ * @return 0 if the arguments are identical and {...@code
+ * c.compare(a, b)} otherwise.
+ * @see Comparable
+ * @see Comparator
+ */
+ public static <T> int compare(T a, T b, Comparator<? super T> c) {
+ return (a == b) ? 0 : c.compare(a, b);
+ }
+}
--- /dev/null 2009-07-06 20:02:10.000000000 -0700
+++ new/test/java/util/Objects/BasicObjectsTest.java 2009-10-08
11:04:04.000000000 -0700
@@ -0,0 +1,105 @@
+/*
+ * Copyright 2009 Sun Microsystems, 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 6797535
+ * @summary Basic tests for methods in java.util.Objects
+ * @author Joseph D. Darcy
+ */
+
+import java.util.*;
+
+public class BasicObjectsTest {
+ public static void main(String... args) {
+ int errors = 0;
+ errors += testEquals();
+ errors += testHashCode();
+ errors += testToString();
+ errors += testCompare();
+ if (errors > 0 )
+ throw new RuntimeException();
+ }
+
+ private static int testEquals() {
+ int errors = 0;
+ Object[] values = {null, "42", 42};
+ for(int i = 0; i < values.length; i++)
+ for(int j = 0; j < values.length; j++) {
+ boolean expected = (i == j);
+ Object a = values[i];
+ Object b = values[j];
+ boolean result = Objects.equals(a, b);
+ if (result != expected) {
+ errors++;
+ System.err.printf("When equating %s to %s, got %b intead of
%b%n.",
+ a, b, result, expected);
+ }
+ }
+ return errors;
+ }
+
+ private static int testHashCode() {
+ int errors = 0;
+ errors += (Objects.hashCode(null) == 0 ) ? 0 : 1;
+ String s = "42";
+ errors += (Objects.hashCode(s) == s.hashCode() ) ? 0 : 1;
+ return errors;
+ }
+
+ private static int testToString() {
+ int errors = 0;
+ errors += ("null".equals(Objects.toString(null)) ) ? 0 : 1;
+ String s = "Some string";
+ errors += (s.equals(Objects.toString(s)) ) ? 0 : 1;
+ return errors;
+ }
+
+ private static int testCompare() {
+ int errors = 0;
+ String[] values = {"e. e. cummings", "zzz"};
+ String[] VALUES = {"E. E. Cummings", "ZZZ"};
+ errors += compareTest(null, null, 0);
+ for(int i = 0; i < values.length; i++) {
+ String a = values[i];
+ errors += compareTest(a, a, 0);
+ for(int j = 0; j < VALUES.length; j++) {
+ int expected = Integer.compare(i, j);
+ String b = VALUES[j];
+ errors += compareTest(a, b, expected);
+ }
+ }
+ return errors;
+ }
+
+ private static int compareTest(String a, String b, int expected) {
+ int errors = 0;
+ int result = Objects.compare(a, b, String.CASE_INSENSITIVE_ORDER);
+ if (Integer.signum(result) != Integer.signum(expected)) {
+ errors++;
+ System.err.printf("When comaping %s to %s, got %d intead of %d%n.",
+ a, b, result, expected);
+ }
+ return errors;
+ }
+}
