Here you can find the source of doubleQuoteIfNotNull(String str)
public static String doubleQuoteIfNotNull(String str)
//package com.java2s; // in accordance with the terms of the license agreement accompanying it. public class Main { public static String doubleQuoteIfNotNull(String str) { return str = (str != null) ? str = "\"" + str + "\"" : null; }//from ww w . ja v a 2 s .c o m }