1 /* 2 * Copyright (c) 2020, 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.jfr.event.runtime; 27 28 import java.io.IOException; 29 import java.io.InputStream; 30 import java.util.ArrayList; 31 import java.util.List; 32 33 /** 34 * Helper class for working with class files and byte arrays 35 */ 36 public final class Bytes { 37 public final static byte[] WORLD = Bytes.asBytes("world"); 38 public final static byte[] EARTH = Bytes.asBytes("earth"); 39 asBytes(String string)40 public static byte[] asBytes(String string) { 41 byte[] result = new byte[string.length()]; 42 for (int i = 0; i < string.length(); i++) { 43 result[i] = (byte)string.charAt(i); 44 } 45 return result; 46 } 47 classBytes(ClassLoader classLoader, String className)48 public static byte[] classBytes(ClassLoader classLoader, String className) throws IOException { 49 String classFileName = className.replace(".", "/") + ".class"; 50 try (InputStream is = classLoader.getResourceAsStream(classFileName)) { 51 if (is == null) { 52 throw new IOException("Could not find class file " + classFileName); 53 } 54 return is.readAllBytes(); 55 } 56 } 57 classBytes(Class<?> clazz)58 public static byte[] classBytes(Class<?> clazz) throws IOException { 59 return classBytes(clazz.getClassLoader(), clazz.getName()); 60 } 61 replaceAll(byte[] input, byte[] target, byte[] replacement)62 public static byte[] replaceAll(byte[] input, byte[] target, byte[] replacement) { 63 List<Byte> result = new ArrayList<>(); 64 for (int i = 0; i < input.length; i++) { 65 if (hasTarget(input, i, target)) { 66 for (int j = 0; j < replacement.length; j++) { 67 result.add(replacement[j]); 68 } 69 i += target.length - 1; 70 } else { 71 result.add(input[i]); 72 } 73 } 74 byte[] resultArray = new byte[result.size()]; 75 for (int i = 0; i < resultArray.length; i++) { 76 resultArray[i] = result.get(i); 77 } 78 return resultArray; 79 } 80 hasTarget(byte[] input, int start, byte[] target)81 private static boolean hasTarget(byte[] input, int start, byte[] target) { 82 for (int i = 0; i < target.length; i++) { 83 if (start + i == input.length) { 84 return false; 85 } 86 if (input[start + i] != target[i]) { 87 return false; 88 } 89 } 90 return true; 91 } 92 } 93