org.onlab.util.HexString Maven / Gradle / Ivy
/*
* Copyright 2014-present Open Networking Foundation
*
* 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 org.onlab.util;
public final class HexString {
private static final char[] HEX_CHARS = "0123456789abcdef".toCharArray();
private HexString() {
}
/**
* Convert a byte array to a colon-separated hex string.
*
* @param bytes byte array to be converted
* @return converted colon-separated hex string, e.g. "0f:ca:fe:de:ad:be:ef",
* or "(null)" if given byte array is null
*/
public static String toHexString(final byte[] bytes) {
return toHexString(bytes, ":");
}
/**
* Convert a byte array to a hex string separated by given separator.
*
* @param bytes byte array to be converted
* @param separator the string use to separate each byte
* @return converted hex string, or "(null)" if given byte array is null
*/
public static String toHexString(final byte[] bytes, String separator) {
if (bytes == null) {
return "(null)";
}
if (separator == null) {
separator = "";
}
int slen = bytes.length * (2 + separator.length()) - separator.length();
StringBuilder ret = new StringBuilder(slen);
boolean addSeparator = !separator.isEmpty();
for (int i = 0; i < bytes.length; i++) {
if (i > 0 && addSeparator) {
ret.append(separator);
}
ret.append(HEX_CHARS[(bytes[i] >> 4) & 0xF]);
ret.append(HEX_CHARS[(bytes[i] & 0xF)]);
}
return ret.toString();
}
/**
* Convert a long number to colon-separated hex string.
* Prepend zero padding until given length.
*
* @param val long number to be converted
* @param padTo prepend zeros until this length
* @return converted colon-separated hex string, e.g. "0f:ca:fe:de:ad:be:ef"
*/
public static String toHexString(final long val, final int padTo) {
char[] arr = Long.toHexString(val).toCharArray();
StringBuilder ret = new StringBuilder(padTo * 3 - 1);
// prepend the right number of leading zeros
int i = 0;
for (; i < (padTo * 2 - arr.length); i++) {
ret.append('0');
if ((i % 2) != 0) {
ret.append(':');
}
}
for (int j = 0; j < arr.length; j++) {
ret.append(arr[j]);
if ((((i + j) % 2) != 0) && (j < (arr.length - 1))) {
ret.append(':');
}
}
return ret.toString();
}
/**
* Convert a long number to colon-separated hex string.
* Prepend zero padding until 8 bytes.
*
* @param val long number to be converted
* @return converted colon-separated hex string, e.g. "0f:ca:fe:de:ad:be:ef"
*/
public static String toHexString(final long val) {
return toHexString(val, 8);
}
/**
* Convert a colon-separated hex string to byte array.
*
* @param values colon-separated hex string to be converted,
* e.g. "0f:ca:fe:de:ad:be:ef"
* @return converted byte array
* @throws NumberFormatException if input hex string cannot be parsed
*/
public static byte[] fromHexString(final String values) {
return fromHexString(values, ":");
}
/**
* Convert a hex-string with arbitrary separator to byte array.
* If separator is the empty string or null, then no separator will be considered.
*
* @param values hex string to be converted
* @param separator regex for separator
* @return converted byte array
* @throws NumberFormatException if input hex string cannot be parsed
*/
public static byte[] fromHexString(final String values, String separator) {
String regexSeparator;
if (separator == null || separator.length() == 0) {
regexSeparator = "(?<=\\G.{2})"; // Split string into several two character strings
} else {
regexSeparator = separator;
}
String[] octets = values.split(regexSeparator);
byte[] ret = new byte[octets.length];
for (int i = 0; i < octets.length; i++) {
if (octets[i].length() > 2) {
throw new NumberFormatException("Invalid octet length");
}
ret[i] = Integer.valueOf(octets[i], 16).byteValue();
}
return ret;
}
/**
* Convert a colon-separated hex string to long.
*
* @param value colon-separated hex string to be converted,
* e.g. "00:0f:ca:fe:de:ad:be:ef"
* @return converted long number
* @throws NumberFormatException if input hex string cannot be parsed
*/
public static long toLong(String value) {
String[] octets = value.split(":");
if (octets.length > 8) {
throw new NumberFormatException("Input string is too big to fit in long: " + value);
}
long l = 0;
for (String octet: octets) {
if (octet.length() > 2) {
throw new NumberFormatException(
"Each colon-separated byte component must consist of 1 or 2 hex digits: " + value);
}
short s = Short.parseShort(octet, 16);
l = (l << 8) + s;
}
return l;
}
}