1 /*

     2  * Copyright (c) 2013, 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.

     8  *

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

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

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

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

    13  * accompanied this code).

    14  *

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

    16  * 2 along with this work; if not, write to the Free Software Foundation,

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

    18  *

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

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

    21  * questions.

    22  */

    23 

    24 package com.oracle.java.testlibrary;

    25 

    26 import java.security.SecureClassLoader;

    27 

    28 /**

    29  * {@code ByteCodeLoader} can be used for easy loading of byte code already

    30  * present in memory.

    31  *

    32  * {@code InMemoryCompiler} can be used for compiling source code in a string

    33  * into byte code, which then can be loaded with {@code ByteCodeLoader}.

    34  *

    35  * @see InMemoryCompiler

    36  */

    37 public class ByteCodeLoader extends SecureClassLoader {

    38     private final String className;

    39     private final byte[] byteCode;

    40 

    41     /**

    42      * Creates a new {@code ByteCodeLoader} ready to load a class with the

    43      * given name and the given byte code.

    44      *

    45      * @param className The name of the class

    46      * @param byteCode The byte code of the class

    47      */

    48     public ByteCodeLoader(String className, byte[] byteCode) {

    49         this.className = className;

    50         this.byteCode = byteCode;

    51     }

    52 

    53     @Override

    54     protected Class<?> findClass(String name) throws ClassNotFoundException {

    55         if (!name.equals(className)) {

    56             throw new ClassNotFoundException(name);

    57         }

    58 

    59         return defineClass(name, byteCode, 0, byteCode.length);

    60     }

    61 

    62     /**

    63      * Utility method for creating a new {@code ByteCodeLoader} and then

    64      * directly load the given byte code.

    65      *

    66      * @param className The name of the class

    67      * @param byteCode The byte code for the class

    68      * @throws ClassNotFoundException if the class can't be loaded

    69      * @return A {@see Class} object representing the class

    70      */

    71     public static Class<?> load(String className, byte[] byteCode) throws ClassNotFoundException {

    72         return new ByteCodeLoader(className, byteCode).loadClass(className);

    73     }

    74 }