Class StringUtils


  • public class StringUtils
    extends Object
    • Constructor Detail

      • StringUtils

        public StringUtils()
    • Method Detail

      • isEmpty

        public static boolean isEmpty​(CharSequence cs)
      • isBlank

        public static boolean isBlank​(String s)
      • leftPad

        public static String leftPad​(String str,
                                     int size,
                                     String padStr)

        Left pad a String with a specified String.

        Pad to a size of size.

         StringUtils.leftPad(null, *, *)      = null
         StringUtils.leftPad("", 3, "z")      = "zzz"
         StringUtils.leftPad("bat", 3, "yz")  = "bat"
         StringUtils.leftPad("bat", 5, "yz")  = "yzbat"
         StringUtils.leftPad("bat", 8, "yz")  = "yzyzybat"
         StringUtils.leftPad("bat", 1, "yz")  = "bat"
         StringUtils.leftPad("bat", -1, "yz") = "bat"
         StringUtils.leftPad("bat", 5, null)  = "  bat"
         StringUtils.leftPad("bat", 5, "")    = "  bat"
         
        Parameters:
        str - the String to pad out, may be null
        size - the size to pad to
        padStr - the String to pad with, null or empty treated as single space
        Returns:
        left padded String or original String if no padding is necessary, null if null String input
      • leftPad

        public static String leftPad​(String str,
                                     int size,
                                     char padChar)
      • repeat

        public static String repeat​(char ch,
                                    int repeat)

        Returns padding using the specified delimiter repeated to a given length.

         StringUtils.repeat('e', 0)  = ""
         StringUtils.repeat('e', 3)  = "eee"
         StringUtils.repeat('e', -2) = ""
         

        Note: this method does not support padding with Unicode Supplementary Characters as they require a pair of chars to be represented. If you are needing to support full I18N of your applications consider using repeat(String, int) instead.

        Parameters:
        ch - character to repeat
        repeat - number of times to repeat char, negative treated as zero
        Returns:
        String with repeated character
        See Also:
        repeat(String, int)
      • repeat

        public static String repeat​(String str,
                                    int repeat)

        Repeat a String repeat times to form a new String.

         StringUtils.repeat(null, 2) = null
         StringUtils.repeat("", 0)   = ""
         StringUtils.repeat("", 2)   = ""
         StringUtils.repeat("a", 3)  = "aaa"
         StringUtils.repeat("ab", 2) = "abab"
         StringUtils.repeat("a", -2) = ""
         
        Parameters:
        str - the String to repeat, may be null
        repeat - number of times to repeat str, negative treated as zero
        Returns:
        a new String consisting of the original String repeated, null if null String input