| /* |
| * Copyright (C) 2016 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package com.android.apksigner; |
| |
| import java.nio.ByteBuffer; |
| |
| /** |
| * Hexadecimal encoding where each byte is represented by two hexadecimal digits. |
| */ |
| class HexEncoding { |
| |
| /** Hidden constructor to prevent instantiation. */ |
| private HexEncoding() {} |
| |
| private static final char[] HEX_DIGITS = "0123456789abcdef".toCharArray(); |
| |
| /** |
| * Encodes the provided data as a hexadecimal string. |
| */ |
| public static String encode(byte[] data, int offset, int length) { |
| StringBuilder result = new StringBuilder(length * 2); |
| for (int i = 0; i < length; i++) { |
| byte b = data[offset + i]; |
| result.append(HEX_DIGITS[(b >>> 4) & 0x0f]); |
| result.append(HEX_DIGITS[b & 0x0f]); |
| } |
| return result.toString(); |
| } |
| |
| /** |
| * Encodes the provided data as a hexadecimal string. |
| */ |
| public static String encode(byte[] data) { |
| return encode(data, 0, data.length); |
| } |
| |
| /** |
| * Encodes the remaining bytes of the provided {@link ByteBuffer} as a hexadecimal string. |
| */ |
| public static String encodeRemaining(ByteBuffer data) { |
| return encode(data.array(), data.arrayOffset() + data.position(), data.remaining()); |
| } |
| } |