| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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 org.apache.jackrabbit.oak.commons; |
| |
| import static com.google.common.base.Preconditions.checkArgument; |
| import static com.google.common.base.Preconditions.checkNotNull; |
| |
| import org.jetbrains.annotations.NotNull; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * Some string utility methods. |
| */ |
| public class StringUtils { |
| |
| private static final Logger LOG = LoggerFactory.getLogger(StringUtils.class); |
| |
| private static final char[] HEX = "0123456789abcdef".toCharArray(); |
| |
| private StringUtils() {} |
| |
| /** |
| * Convert a byte array to a hex encoded string. |
| * |
| * @param value the byte array |
| * @return the hex encoded string |
| */ |
| @NotNull |
| public static String convertBytesToHex(@NotNull byte[] value) { |
| checkNotNull(value); |
| int len = value.length; |
| char[] buff = new char[len + len]; |
| char[] hex = HEX; |
| for (int i = 0; i < len; i++) { |
| int c = value[i] & 0xff; |
| buff[i + i] = hex[c >> 4]; |
| buff[i + i + 1] = hex[c & 0xf]; |
| } |
| return new String(buff); |
| } |
| |
| /** |
| * Convert a hex encoded string to a byte array. |
| * |
| * @param s the hex encoded string |
| * @return the byte array |
| */ |
| @NotNull |
| public static byte[] convertHexToBytes(@NotNull String s) { |
| checkNotNull(s); |
| int len = s.length(); |
| checkArgument(len % 2 == 0); |
| |
| len /= 2; |
| byte[] buff = new byte[len]; |
| for (int i = 0; i < len; i++) { |
| buff[i] = (byte) ((getHexDigit(s, i + i) << 4) | getHexDigit(s, i + i + 1)); |
| } |
| return buff; |
| } |
| |
| /** |
| * Convert the digit at the given position to a hex number. |
| * |
| * @param s the hex encoded string |
| * @param i the index |
| * @return the number |
| */ |
| private static int getHexDigit(String s, int i) { |
| char c = s.charAt(i); |
| if (c >= '0' && c <= '9') { |
| return c - '0'; |
| } else if (c >= 'a' && c <= 'f') { |
| return c - 'a' + 0xa; |
| } else if (c >= 'A' && c <= 'F') { |
| return c - 'A' + 0xa; |
| } else { |
| throw new IllegalArgumentException(s); |
| } |
| } |
| |
| /** |
| * Estimates the memory usage of the given string. |
| * |
| * @param s the string to estimate. |
| * @return the estimated memory usage. |
| */ |
| public static int estimateMemoryUsage(String s) { |
| long size = s == null ? 0 : 48 + (long)s.length() * 2; |
| if (size > Integer.MAX_VALUE) { |
| LOG.debug("Estimated memory footprint larger than Integer.MAX_VALUE: {}.", size); |
| size = Integer.MAX_VALUE; |
| } |
| return (int) size; |
| } |
| } |