test/java/util/zip/InflaterInputStream/TestAvailable.java

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
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 * 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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/* @test
 * @library /lib/testlibrary/
 * @build jdk.testlibrary.*
 * @run main TestAvailable
 * @bug 7031075 8161426
 * @summary Make sure that available() method behaves as expected.
 * @key randomness
 */

import java.io.*;
import java.util.Random;
import java.util.zip.*;
import jdk.testlibrary.RandomFactory;

public class TestAvailable {

    public static void main(String args[]) throws Throwable {
        Random r = RandomFactory.getRandom();
        for (int n = 0; n < 10; n++) {
            byte[] src = new byte[r.nextInt(100) + 1];
            r.nextBytes(src);
            // test InflaterInputStream
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            try (DeflaterOutputStream dos = new DeflaterOutputStream(baos)) {
                dos.write(src);
            }
            try (InflaterInputStream iis = new InflaterInputStream(
                   new ByteArrayInputStream(baos.toByteArray()))) {
                test(iis, src);
            }

            // test GZIPInputStream
            baos = new ByteArrayOutputStream();
            try (GZIPOutputStream dos = new GZIPOutputStream(baos)) {
                dos.write(src);
            }
            try (GZIPInputStream gis = new GZIPInputStream(
                   new ByteArrayInputStream(baos.toByteArray()))) {
                test(gis, src);
            }
        }
    }

    private static void test(InputStream is, byte[] expected) throws IOException {
        int cnt = 0;
        do {
            int available = is.available();
            if (available > 0) {
                int b = is.read();
                if (b == -1) {
                    throw new RuntimeException("available() > 0, read() == -1 : failed!");
                }
                if (expected[cnt++] != (byte)b) {
                    throw new RuntimeException("read() : failed!");
                }
            } else if (available == 0) {
                if (is.read() != -1) {
                    throw new RuntimeException("available() == 0, read() != -1 : failed!");
                }
                break;
            } else {
                throw new RuntimeException("available() < 0 : failed!");
            }
        } while (true);
        if (cnt != expected.length) {
            throw new RuntimeException("read : failed!");
        }
    }

}