Here you can find the source of encodeURL(BigInteger id)
public static String encodeURL(BigInteger id)
//package com.java2s; /*/*from w ww .ja va 2 s . c o m*/ * * * The MIT License (MIT) * * Copyright (c) 2016 Saurabh Sejpal * * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated * documentation files (the "Software"), to deal in the Software without restriction, including without limitation the * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit * persons to whom the Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the * Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT * NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. * */ import java.math.BigInteger; public class Main { private static final String ALPHABET = "23456789bcdfghjkmnpqrstvwxyzBCDFGHJKLMNPQRSTVWXYZ-_"; private static final BigInteger BASE = new BigInteger(String.valueOf(ALPHABET.length())); public static String encodeURL(BigInteger id) { StringBuilder str = new StringBuilder(); BigInteger primaryKey = new BigInteger(String.valueOf(id)); while (primaryKey.compareTo(BigInteger.ZERO) == 1) { str.insert(0, ALPHABET.charAt(primaryKey.mod(BASE).intValue())); primaryKey = primaryKey.divide(BASE); } return str.toString(); } }