Here you can find the source of toCamelCase(String s, Boolean firstUpper)
public static String toCamelCase(String s, Boolean firstUpper)
//package com.java2s; /**//from w w w . ja va 2 s .c o m * Copyright 2002-2016 Evgeny Gryaznov * * 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. */ public class Main { public static String toCamelCase(String s, Boolean firstUpper) { char[] string = s.toCharArray(); int len = 0; boolean nextUpper = firstUpper; for (int i = 0; i < string.length; i++) { char c = string[i]; if (c == '_') { nextUpper = true; } else if (nextUpper) { string[len] = len > 0 || firstUpper ? Character.toUpperCase(c) : c; len++; nextUpper = false; } else { string[len++] = c; } } return new String(string, 0, len); } }