Java example source code file (ManyNewInstanceAnonTest.java)

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Java - Java tags/keywords

bytearrayoutputstream, class, exception, inputstream, manynewinstanceanontest, reps

The ManyNewInstanceAnonTest.java Java example source code

/*
 * Copyright (c) 2013, 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 7194897
 * @summary JSR 292: Cannot create more than 16 instances of an anonymous class
 * @author  Robert Field
 * @library /lib/testlibrary
 * @compile -XDignore.symbol.file ManyNewInstanceAnonTest.java
 * @run main ClassFileInstaller ManyNewInstanceAnonTest
 * @run main/othervm -Xbootclasspath/a:. -Xverify:all ManyNewInstanceAnonTest
 * @run main/othervm -Xbootclasspath/a:. -Xverify:all -Dsun.reflection.noInflation=true ManyNewInstanceAnonTest
 */
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import sun.misc.Unsafe;

public class ManyNewInstanceAnonTest {

    static final int REPS = 20;
    static final Class<?> klass = ManyNewInstanceAnonTest.class;

    public static void main(String[] args) throws Exception {
        Class<?> c = Unsafe.getUnsafe().defineAnonymousClass(klass, readClassFile(), null);
        for (int i = 0; i < REPS; ++i) {
            System.out.printf("%d: %s\n", i, c.newInstance());
        }
        System.out.println("Passed.");
    }

    private static byte[] readClassFile() throws Exception {
        try (InputStream in = klass.getResourceAsStream(klass.getSimpleName() + ".class");
             ByteArrayOutputStream out = new ByteArrayOutputStream())
        {
            int b;
            while ((b = in.read()) != -1) {
                out.write(b);
            }
            return out.toByteArray();
        }
    }
}