01: /***
02: * Retrotranslator: a Java bytecode transformer that translates Java classes
03: * compiled with JDK 5.0 into classes that can be run on JVM 1.4.
04: *
05: * Copyright (c) 2005 - 2008 Taras Puchko
06: * All rights reserved.
07: *
08: * Redistribution and use in source and binary forms, with or without
09: * modification, are permitted provided that the following conditions
10: * are met:
11: * 1. Redistributions of source code must retain the above copyright
12: * notice, this list of conditions and the following disclaimer.
13: * 2. Redistributions in binary form must reproduce the above copyright
14: * notice, this list of conditions and the following disclaimer in the
15: * documentation and/or other materials provided with the distribution.
16: * 3. Neither the name of the copyright holders nor the names of its
17: * contributors may be used to endorse or promote products derived from
18: * this software without specific prior written permission.
19: *
20: * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
21: * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23: * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
24: * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25: * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26: * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27: * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28: * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29: * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
30: * THE POSSIBILITY OF SUCH DAMAGE.
31: */package net.sf.retrotranslator.transformer;
32:
33: import net.sf.retrotranslator.runtime.asm.Type;
34:
35: /**
36: * @author Taras Puchko
37: */
38: class TransformerTools {
39:
40: public static String descriptor(Class returnType,
41: Class... parameterTypes) {
42: Type[] argumentTypes = new Type[parameterTypes.length];
43: for (int i = 0; i < argumentTypes.length; i++) {
44: argumentTypes[i] = Type.getType(parameterTypes[i]);
45: }
46: return Type.getMethodDescriptor(Type.getType(returnType),
47: argumentTypes);
48: }
49:
50: public static Type getTypeByInternalName(String name) {
51: return Type.getType('L' + name + ';');
52: }
53:
54: public static Type getArrayTypeByInternalName(String name,
55: int dimensions) {
56: StringBuilder builder = new StringBuilder();
57: for (int i = 0; i < dimensions; i++) {
58: builder.append('[');
59: }
60: return Type.getType(builder.append('L').append(name)
61: .append(';').toString());
62: }
63:
64: public static boolean isClassFile(byte[] bytes) {
65: return bytes.length >= 4 && bytes[0] == ((byte) 0xCA)
66: && bytes[1] == ((byte) 0xFE)
67: && bytes[2] == ((byte) 0xBA)
68: && bytes[3] == ((byte) 0xBE);
69: }
70:
71: public static int getClassVersion(byte[] bytes, int offset) {
72: return get(bytes, offset, 4, 24) | get(bytes, offset, 5, 16)
73: | get(bytes, offset, 6, 8) | get(bytes, offset, 7, 0);
74: }
75:
76: private static int get(byte[] bytes, int offset, int index,
77: int shift) {
78: return (bytes[offset + index] & 0xFF) << shift;
79: }
80:
81: public static ClassLoader getDefaultClassLoader() {
82: ClassLoader classLoader = TransformerTools.class
83: .getClassLoader();
84: return classLoader != null ? classLoader : ClassLoader
85: .getSystemClassLoader();
86: }
87:
88: }
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