public class Strings extends Object
Constructor and Description |
---|
Strings() |
Modifier and Type | Method and Description |
---|---|
static String |
emptyToNull(String string)
Returns the given string if it is nonempty;
null otherwise. |
static boolean |
isNullOrEmpty(String string)
Returns
true if the given string is null or is the empty string. |
static String |
nullToEmpty(String string)
Returns the given string if it is non-null; the empty string otherwise.
|
static String |
padEnd(String string,
int minLength,
char padChar)
Returns a string, of length at least
minLength , consisting of
string appended with as many copies of padChar as are
necessary to reach that length. |
static String |
padStart(String string,
int minLength,
char padChar)
Returns a string, of length at least
minLength , consisting of
string prepended with as many copies of padChar as are
necessary to reach that length. |
static String |
repeat(String string,
int count)
Returns a string consisting of a specific number of concatenated copies of
an input string.
|
public static String nullToEmpty(String string)
string
- the string to test and possibly returnstring
itself if it is non-null; ""
if it is nullpublic static String emptyToNull(String string)
null
otherwise.string
- the string to test and possibly returnstring
itself if it is nonempty; null
if it is
empty or nullpublic static boolean isNullOrEmpty(String string)
true
if the given string is null or is the empty string.
Consider normalizing your string references with nullToEmpty(java.lang.String)
.
If you do, you can use String.isEmpty()
instead of this
method, and you won't need special null-safe forms of methods like String.toUpperCase(java.util.Locale)
either. Or, if you'd like to normalize "in the other
direction," converting empty strings to null
, you can use emptyToNull(java.lang.String)
.
string
- a string reference to checktrue
if the string is null or is the empty stringpublic static String padStart(String string, int minLength, char padChar)
minLength
, consisting of
string
prepended with as many copies of padChar
as are
necessary to reach that length. For example,
padStart("7", 3, '0')
returns "007"
padStart("2010", 3, '0')
returns "2010"
string
- the string which should appear at the end of the resultminLength
- the minimum length the resulting string must have. Can be
zero or negative, in which case the input string is always returned.padChar
- the character to insert at the beginning of the result until
the minimum length is reachedpublic static String padEnd(String string, int minLength, char padChar)
minLength
, consisting of
string
appended with as many copies of padChar
as are
necessary to reach that length. For example,
padEnd("4.", 5, '0')
returns "4.000"
padEnd("2010", 3, '!')
returns "2010"
string
- the string which should appear at the beginning of the resultminLength
- the minimum length the resulting string must have. Can be
zero or negative, in which case the input string is always returned.padChar
- the character to append to the end of the result until the
minimum length is reachedpublic static String repeat(String string, int count)
repeat("hey", 3)
returns the string
"heyheyhey"
.string
- any non-null stringcount
- the number of times to repeat it; a nonnegative integerstring
repeated count
times
(the empty string if count
is zero)IllegalArgumentException
- if count
is negativeCopyright © 2013–2017 impossibl.com. All rights reserved.