1 /*

     2  * Copyright (c) 2013, 2018, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.  Oracle designates this

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

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

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    22  * or visit www.oracle.com if you need additional information or have any

    23  * questions.

    24  */

    25 

    26 package jdk.test.lib.jfr;

    27 

    28 import java.io.DataInputStream;

    29 import java.io.IOException;

    30 import java.io.InputStream;

    31 

    32 /**

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

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

    35  */

    36 public class TestClassLoader extends ClassLoader {

    37     static public final String CLASS_LOADER_NAME = "JFR TestClassLoader";

    38 

    39     public TestClassLoader() {

    40         super(CLASS_LOADER_NAME, ClassLoader.getSystemClassLoader());

    41     }

    42 

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

    44 

    45         InputStream is = null;

    46         DataInputStream dis = null;

    47         try {

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

    49             is = getResourceAsStream(resourceName);

    50             if (is != null) {

    51                 int i = is.available();

    52                 byte buf[] = new byte[i];

    53                 dis = new DataInputStream(is);

    54                 dis.readFully(buf);

    55                 dis.close();

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

    57             }

    58         } catch (SecurityException e) {

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

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

    61             // Ignore this error and use parent class loader.

    62         } catch (IOException e) {

    63             // Unexpected error. Use parent class loader.

    64             e.printStackTrace();

    65         } finally {

    66             if (dis != null) {

    67                 try {

    68                     dis.close();

    69                 } catch (IOException e) {

    70                     e.printStackTrace();

    71                 }

    72             }

    73         }

    74         return super.loadClass(name);

    75     }

    76 

    77 }