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/* |
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* Copyright (c) 2005, Oracle and/or its affiliates. All rights reserved. |
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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* |
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* This code is free software; you can redistribute it and/or modify it |
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* under the terms of the GNU General Public License version 2 only, as |
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* published by the Free Software Foundation. |
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* |
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* This code is distributed in the hope that it will be useful, but WITHOUT |
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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* version 2 for more details (a copy is included in the LICENSE file that |
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* accompanied this code). |
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* |
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* You should have received a copy of the GNU General Public License version |
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* 2 along with this work; if not, write to the Free Software Foundation, |
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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* |
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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* or visit www.oracle.com if you need additional information or have any |
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* questions. |
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*/ |
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|
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/* |
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* @test |
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* @bug 5018254 |
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* @summary Test null-allowing Comparators |
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* @author Martin Buchholz |
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*/ |
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|
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import java.util.Comparator; |
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import java.util.SortedMap; |
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import java.util.TreeMap; |
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|
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public class NullAtEnd { |
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static volatile int passed = 0, failed = 0; |
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|
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static void fail(String msg) { |
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failed++; |
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new AssertionError(msg).printStackTrace(); |
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} |
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|
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static void pass() { |
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passed++; |
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} |
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|
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static void unexpected(Throwable t) { |
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failed++; |
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t.printStackTrace(); |
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} |
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|
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static void check(boolean condition, String msg) { |
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if (condition) |
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passed++; |
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else |
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fail(msg); |
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} |
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|
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static void check(boolean condition) { |
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check(condition, "Assertion failure"); |
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} |
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|
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private static boolean eq(Object x, Object y) { |
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return x == null ? y == null : x.equals(y); |
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} |
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|
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private static final Comparator<String> NULL_AT_END |
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= new Comparator<>() { |
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/** |
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* Allows for nulls. Null is greater than anything non-null. |
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*/ |
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public int compare(String x, String y) { |
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if (x == null && y == null) return 0; |
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if (x == null && y != null) return 1; |
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if (x != null && y == null) return -1; |
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return x.compareTo(y); |
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} |
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}; |
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|
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public static void main(String[] args) { |
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try { |
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SortedMap<String,String> m1 = new TreeMap<>(NULL_AT_END); |
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check(eq(m1.put("a", "a"), null)); |
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check(eq(m1.put("b", "b"), null)); |
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check(eq(m1.put("c", "c"), null)); |
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check(eq(m1.put(null, "d"), null)); |
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|
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SortedMap<String,String> m2 = new TreeMap<>(m1); |
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|
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check(eq(m1.lastKey(), null)); |
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check(eq(m1.get(m1.lastKey()), "d")); |
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check(eq(m1.remove(m1.lastKey()), "d")); |
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check(eq(m1.lastKey(), "c")); |
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|
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check(eq(m2.entrySet().toString(), "[a=a, b=b, c=c, null=d]")); |
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|
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SortedMap<String,String> m3 = m2.tailMap("b"); |
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|
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check(eq(m3.lastKey(), null)); |
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check(eq(m3.get(m3.lastKey()), "d")); |
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check(eq(m3.remove(m3.lastKey()), "d")); |
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check(eq(m3.lastKey(), "c")); |
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|
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} catch (Throwable t) { unexpected(t); } |
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|
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System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed); |
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if (failed > 0) throw new Error("Some tests failed"); |
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} |
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} |
