public class StringUtils extends Object
Constructor and Description |
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StringUtils() |
Modifier and Type | Method and Description |
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static boolean |
isBlank(String str)
Checks if a String is whitespace, empty ("") or null.
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static boolean |
isEmpty(String str)
Checks if a String is empty ("") or null.
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static String |
join(Collection strings,
String delimiter)
Joins a collection of string with a given delimiter.
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static String |
join(Object[] array,
String separator)
Joins the elements of the provided array into a single String
containing the provided list of elements.
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static List<String> |
split(String str,
char separatorChar)
Splits the provided text into an array, separator specified.
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public static boolean isEmpty(String str)
Checks if a String is empty ("") or null.
StringUtils.isEmpty(null) = true StringUtils.isEmpty("") = true StringUtils.isEmpty(" ") = false StringUtils.isEmpty("bob") = false StringUtils.isEmpty(" bob ") = false
NOTE: This method changed in Lang version 2.0. It no longer trims the String. That functionality is available in isBlank().
str
- the String to check, may be nulltrue
if the String is empty or nullpublic static boolean isBlank(String str)
Checks if a String is whitespace, empty ("") or null.
StringUtils.isBlank(null) = true StringUtils.isBlank("") = true StringUtils.isBlank(" ") = true StringUtils.isBlank("bob") = false StringUtils.isBlank(" bob ") = false
str
- the String to check, may be nulltrue
if the String is null, empty or whitespacepublic static String join(Object[] array, String separator)
Joins the elements of the provided array into a single String containing the provided list of elements.
No delimiter is added before or after the list.
A null
separator is the same as an empty String ("").
Null objects or empty strings within the array are represented by
empty strings.
StringUtils.join(null, *) = null StringUtils.join([], *) = "" StringUtils.join([null], *) = "" StringUtils.join(["a", "b", "c"], "--") = "a--b--c" StringUtils.join(["a", "b", "c"], null) = "abc" StringUtils.join(["a", "b", "c"], "") = "abc" StringUtils.join([null, "", "a"], ',') = ",,a"
array
- the array of values to join together, may be nullseparator
- the separator character to use, null treated as ""null
if null array inputpublic static String join(Collection strings, String delimiter)
strings
- The collection of strings to join.delimiter
- The delimiter to use to join them.public static List<String> split(String str, char separatorChar)
Splits the provided text into an array, separator specified. This is an alternative to using StringTokenizer.
The separator is not included in the returned String array. Adjacent separators are treated as one separator. For more control over the split use the StrTokenizer class.
A null
input String returns null
.
StringUtils.split(null, *) = null StringUtils.split("", *) = [] StringUtils.split("a.b.c", '.') = ["a", "b", "c"] StringUtils.split("a..b.c", '.') = ["a", "b", "c"] StringUtils.split("a:b:c", '.') = ["a:b:c"] StringUtils.split("a b c", ' ') = ["a", "b", "c"]
str
- the String to parse, may be nullseparatorChar
- the character used as the delimiternull
if null String inputCopyright © 2012–2020 JBoss by Red Hat. All rights reserved.