Here you can find the source of toLong(Object obj)
public static long toLong(Object obj) throws Exception
//package com.java2s; public class Main { public static long toLong(Object obj) throws Exception { return Long.parseLong(toString(obj).trim()); }/*from ww w . j a v a 2s.c om*/ public static long toLong(Object obj, long defaultValue) { try { return toLong(obj); } catch (Exception ex) { return defaultValue; } } public static String toString(double obj) throws Exception { return Double.toString(obj); } public static String toString(double obj, String defaultValue) { try { return toString(obj); } catch (Exception ex) { return defaultValue; } } public static String toString(int obj) throws Exception { return Integer.toString(obj); } public static String toString(int obj, String defaultValue) { try { return toString(obj); } catch (Exception ex) { return defaultValue; } } public static String toString(long obj) throws Exception { return Long.toString(obj); } public static String toString(long obj, String defaultValue) { try { return toString(obj); } catch (Exception ex) { return defaultValue; } } public static String toString(Object obj) throws Exception { if (obj == null) { return ""; } return String.valueOf(obj); } public static String toString(Object obj, String defaultValue) { try { return toString(obj); } catch (Exception ex) { return defaultValue; } } }