/*

 * Copyright (c) 2013, 2018, 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.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * 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.

 */

package jdk.test.lib.jfr;

import java.io.DataInputStream;

import java.io.IOException;

import java.io.InputStream;

/**

 * Custom class loader which will try to load the class via getResourceAsStream().

 * If there are any errors, the parent class loader will be used instead.

 */

public class TestClassLoader extends ClassLoader {

    static public final String CLASS_LOADER_NAME = "JFR TestClassLoader";

    public TestClassLoader() {

        super(CLASS_LOADER_NAME, ClassLoader.getSystemClassLoader());

    }

    public Class<?> loadClass(String name) throws ClassNotFoundException {

        InputStream is = null;

        DataInputStream dis = null;

        try {

            String resourceName = name.replace('.', '/') + ".class";

            is = getResourceAsStream(resourceName);

            if (is != null) {

                int i = is.available();

                byte buf[] = new byte[i];

                dis = new DataInputStream(is);

                dis.readFully(buf);

                dis.close();

                return defineClass(name, buf, 0, buf.length);

            }

        } catch (SecurityException e) {

            // This error will happen quite often (for example when loading

            // "java.lang...").

            // Ignore this error and use parent class loader.

        } catch (IOException e) {

            // Unexpected error. Use parent class loader.

            e.printStackTrace();

        } finally {

            if (dis != null) {

                try {

                    dis.close();

                } catch (IOException e) {

                    e.printStackTrace();

                }

            }

        }

        return super.loadClass(name);

    }

}