Here you can find the source of valueOf(String first, String defaultstr)
public static String valueOf(String first, String defaultstr)
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THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF * MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. * */ public class Main { /** * returns the value of the first parameter if set, otherwise a default value */ public static String valueOf(String first, String defaultstr) { if ((first != null) && (first.length() > 0)) { return first; } return defaultstr; } }