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/*
* Copyright (c) 2005, 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 5018254
* @summary Test null-allowing Comparators
* @author Martin Buchholz
*/
import java.util.Comparator;
import java.util.SortedMap;
import java.util.TreeMap;
public class NullAtEnd {
static volatile int passed = 0, failed = 0;
static void fail(String msg) {
failed++;
new AssertionError(msg).printStackTrace();
}
static void pass() {
passed++;
}
static void unexpected(Throwable t) {
failed++;
t.printStackTrace();
}
static void check(boolean condition, String msg) {
if (condition)
passed++;
else
fail(msg);
}
static void check(boolean condition) {
check(condition, "Assertion failure");
}
private static boolean eq(Object x, Object y) {
return x == null ? y == null : x.equals(y);
}
private static final Comparator<String> NULL_AT_END
= new Comparator<>() {
/**
* Allows for nulls. Null is greater than anything non-null.
*/
public int compare(String x, String y) {
if (x == null && y == null) return 0;
if (x == null && y != null) return 1;
if (x != null && y == null) return -1;
return x.compareTo(y);
}
};
public static void main(String[] args) {
try {
SortedMap<String,String> m1 = new TreeMap<>(NULL_AT_END);
check(eq(m1.put("a", "a"), null));
check(eq(m1.put("b", "b"), null));
check(eq(m1.put("c", "c"), null));
check(eq(m1.put(null, "d"), null));
SortedMap<String,String> m2 = new TreeMap<>(m1);
check(eq(m1.lastKey(), null));
check(eq(m1.get(m1.lastKey()), "d"));
check(eq(m1.remove(m1.lastKey()), "d"));
check(eq(m1.lastKey(), "c"));
check(eq(m2.entrySet().toString(), "[a=a, b=b, c=c, null=d]"));
SortedMap<String,String> m3 = m2.tailMap("b");
check(eq(m3.lastKey(), null));
check(eq(m3.get(m3.lastKey()), "d"));
check(eq(m3.remove(m3.lastKey()), "d"));
check(eq(m3.lastKey(), "c"));
} catch (Throwable t) { unexpected(t); }
System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
if (failed > 0) throw new Error("Some tests failed");
}
}
¤ Dauer der Verarbeitung: 0.16 Sekunden
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