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/*
* Copyright (c) 2020, 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.
*/
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import org.testng.Assert;
import org.testng.annotations.Test;
/**
* @test
* @bug 8215401
* @summary Test to verify the isEmpty method is behaviorally consistent
* with length
* @run testng Emptiness
*/
public class Emptiness {
@Test
public void isEmpty() {
checkEmpty(new StringBuilder());
checkEmpty(new StringBuffer());
checkEmpty("");
checkEmpty(new CharSequence() {
@Override public int length() { return 0; }
@Override public char charAt(int index) { return 'f'; }
@Override public CharSequence subSequence(int start, int end) {
throw new UnsupportedOperationException();
}
});
checkEmpty(CharBuffer.wrap(new char[0]));
checkEmpty(CharBuffer.wrap(""));
// A CharBuffer being filled is empty when there's no room remaining
// - or there's nothing in the buffer after a flip
checkEmpty(ByteBuffer.allocate(0).asCharBuffer());
checkEmpty(ByteBuffer.allocate(2).asCharBuffer().append('f'));
checkEmpty(ByteBuffer.allocate(2).asCharBuffer().flip());
checkEmpty(ByteBuffer.allocateDirect(0).asCharBuffer());
checkEmpty(ByteBuffer.allocateDirect(2).asCharBuffer().append('f'));
checkEmpty(ByteBuffer.allocateDirect(2).asCharBuffer().flip());
}
@Test
public void isNotEmpty() {
checkNotEmpty(new StringBuilder().append("foo"));
checkNotEmpty(new StringBuffer().append("bar"));
checkNotEmpty("baz");
checkNotEmpty(new CharSequence() {
@Override public int length() { return 1; }
@Override public char charAt(int index) { return 'f'; }
@Override public CharSequence subSequence(int start, int end) {
throw new UnsupportedOperationException();
}
});
checkNotEmpty(CharBuffer.wrap(new char[] { 'f' }));
checkNotEmpty(CharBuffer.wrap("foo"));
// A CharBuffer being filled is non-empty when there's room remaining
// - or when there's something in the buffer after a flip
checkNotEmpty(ByteBuffer.allocate(2).asCharBuffer());
checkNotEmpty(ByteBuffer.allocate(4).asCharBuffer().append('f'));
checkNotEmpty(ByteBuffer.allocate(2).asCharBuffer().append('f').flip());
checkNotEmpty(ByteBuffer.allocateDirect(2).asCharBuffer());
checkNotEmpty(ByteBuffer.allocateDirect(4).asCharBuffer().append('f'));
checkNotEmpty(ByteBuffer.allocateDirect(2).asCharBuffer().append('f').flip());
}
public void checkEmpty(CharSequence cs) {
Assert.assertTrue(cs.isEmpty());
Assert.assertTrue(consistentWithLength(cs));
}
public void checkNotEmpty(CharSequence cs) {
Assert.assertTrue(!cs.isEmpty());
Assert.assertTrue(consistentWithLength(cs));
}
public boolean consistentWithLength(CharSequence cs) {
return cs.isEmpty() == (cs.length() == 0);
}
}
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