Write code to get substring Before separator
//package com.book2s; public class Main { public static void main(String[] argv) { String str = "book2s.com"; String separator = "."; System.out.println(substringBefore(str, separator)); }//from w w w . j a v a 2 s . c om public static String substringBefore(String str, String separator) { if (isEmpty(str) || separator == null) return str; if (separator.length() == 0) return ""; int pos = str.indexOf(separator); if (pos == -1) return str; else return str.substring(0, pos); } public static boolean isEmpty(String str) { return str == null || str.length() == 0; } public static int indexOf(String str, char searchChar, int startPos) { if (isEmpty(str)) return -1; else return str.indexOf(searchChar, startPos); } public static String substring(String str, int start) { if (str == null) return null; if (start < 0) start = str.length() + start; if (start < 0) start = 0; if (start > str.length()) return ""; else return str.substring(start); } public static String substring(String str, int start, int end) { if (str == null) return null; if (end < 0) end = str.length() + end; if (start < 0) start = str.length() + start; if (end > str.length()) end = str.length(); if (start > end) return ""; if (start < 0) start = 0; if (end < 0) end = 0; return str.substring(start, end); } }