/*
* Copyright 2016 Red Hat, Inc. and/or its affiliates.
*
* 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.
*/
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package org.kie.workbench.common.stunner.core.util;
public class UUID {
private static final char[] CHARS = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz".toCharArray();
/**
* Generate a random uuid of the specified length. Example: uuid(15) returns
* "VcydxgltxrVZSTV"
* @param len the desired number of characters
*/
public static String uuid(final int len) {
return uuid(len,
CHARS.length);
}
/**
* Generate a random uuid of the specified length, and radix. Examples:
* <ul>
* <li>uuid(8, 2) returns "01001010" (8 character ID, base=2)
* <li>uuid(8, 10) returns "47473046" (8 character ID, base=10)
* <li>uuid(8, 16) returns "098F4D35" (8 character ID, base=16)
* </ul>
* @param len the desired number of characters
* @param radix the number of allowable values for each character (must be <=
* 62)
*/
public static String uuid(final int len,
final int radix) {
if (radix > CHARS.length) {
throw new IllegalArgumentException();
}
char[] uuid = new char[len];
// Compact form
for (int i = 0; i < len; i++) {
uuid[i] = CHARS[(int) (Math.random() * radix)];
}
return new String(uuid);
}
/**
* Generate a RFC4122, version 4 ID. Example:
* "92329D39-6F5C-4520-ABFC-AAB64544E172"
*/
public static String uuid() {
char[] uuid = new char[36];
int r;
// rfc4122 requires these characters
uuid[8] = uuid[13] = uuid[18] = uuid[23] = '-';
uuid[14] = '4';
// Fill in random data. At i==19 set the high bits of clock sequence as
// per rfc4122, sec. 4.1.5
for (int i = 0; i < 36; i++) {
if (uuid[i] == 0) {
r = (int) (Math.random() * 16);
uuid[i] = CHARS[(i == 19) ? (r & 0x3) | 0x8 : r & 0xf];
}
}
return new String(uuid);
}
}