java-topology/test/jdk/java/util/zip/GZIP/GZIPOutputStreamHeaderTest.java
russell@unturf.com 0a580b313d undefect. CWE-407 — 63 sites patched across 27 ecosystems
Authors: russell@unturf.com · brackishbert@gmail.com · foxhop.net · TimeHexOn.com

Patches, unit tests, benchmarks, whitepaper, and outreach briefs.
Public domain — no copyright claimed. Use freely.
2026-03-26 17:11:57 -04:00

76 lines
3.1 KiB
Java

/*
* Copyright (c) 2020, 2026, 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.
*
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import org.junit.jupiter.api.Test;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.nio.charset.StandardCharsets;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertNotNull;
/**
* @test
* @bug 8244706
* @summary Verify that the OS header flag in the stream written out by java.util.zip.GZIPOutputStream
* has the correct expected value
* @run junit GZIPOutputStreamHeaderTest
*/
public class GZIPOutputStreamHeaderTest {
private static final int OS_HEADER_INDEX = 9;
private static final int HEADER_VALUE_OS_UNKNOWN = 255;
/**
* Test that the {@code OS} header field in the GZIP output stream
* has a value of {@code 255} which represents "unknown"
*/
@Test
public void testOSHeader() throws Exception {
final String data = "Hello world!!!";
final ByteArrayOutputStream baos = new ByteArrayOutputStream();
try (final GZIPOutputStream gzipOutputStream = new GZIPOutputStream(baos);) {
gzipOutputStream.write(data.getBytes(StandardCharsets.UTF_8));
}
final byte[] compressed = baos.toByteArray();
assertNotNull(compressed, "Compressed data is null");
assertEquals(HEADER_VALUE_OS_UNKNOWN, toUnsignedByte(compressed[OS_HEADER_INDEX]),
"Unexpected value for OS header");
// finally verify that the compressed data is readable back to the original
final String uncompressed;
try (final ByteArrayOutputStream os = new ByteArrayOutputStream();
final ByteArrayInputStream bis = new ByteArrayInputStream(compressed);
final GZIPInputStream gzipInputStream = new GZIPInputStream(bis)) {
gzipInputStream.transferTo(os);
uncompressed = new String(os.toByteArray(), StandardCharsets.UTF_8);
}
assertEquals(data, uncompressed, "Unexpected data read from GZIPInputStream");
}
private static int toUnsignedByte(final byte b) {
return b & 0xff;
}
}