org.apache.logging.log4j.util
Class Strings

java.lang.Object
  extended by org.apache.logging.log4j.util.Strings

public final class Strings
extends Object

Consider this class private.

See Also:
Apache Commons Lang

Field Summary
static String EMPTY
          The empty string.
 
Method Summary
static String dquote(String str)
          Returns a double quoted string.
static boolean isBlank(String s)
          Checks if a String is blank.
static boolean isEmpty(CharSequence cs)
           Checks if a CharSequence is empty ("") or null.
static boolean isNotBlank(String s)
          Checks if a String is not blank.
static boolean isNotEmpty(CharSequence cs)
           Checks if a CharSequence is not empty ("") and not null.
static String quote(String str)
          Returns a quoted string.
static String trimToNull(String str)
           Removes control characters (char <= 32) from both ends of this String returning null if the String is empty ("") after the trim or if it is null.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

EMPTY

public static final String EMPTY
The empty string.

See Also:
Constant Field Values
Method Detail

isEmpty

public static boolean isEmpty(CharSequence cs)

Checks if a CharSequence is empty ("") or null.

 Strings.isEmpty(null)      = true
 Strings.isEmpty("")        = true
 Strings.isEmpty(" ")       = false
 Strings.isEmpty("bob")     = false
 Strings.isEmpty("  bob  ") = false
 

NOTE: This method changed in Lang version 2.0. It no longer trims the CharSequence. That functionality is available in isBlank().

Copied from Apache Commons Lang org.apache.commons.lang3.StringUtils.isEmpty(CharSequence)

Parameters:
cs - the CharSequence to check, may be null
Returns:
true if the CharSequence is empty or null

isNotEmpty

public static boolean isNotEmpty(CharSequence cs)

Checks if a CharSequence is not empty ("") and not null.

 Strings.isNotEmpty(null)      = false
 Strings.isNotEmpty("")        = false
 Strings.isNotEmpty(" ")       = true
 Strings.isNotEmpty("bob")     = true
 Strings.isNotEmpty("  bob  ") = true
 

Copied from Apache Commons Lang org.apache.commons.lang3.StringUtils.isNotEmpty(CharSequence)

Parameters:
cs - the CharSequence to check, may be null
Returns:
true if the CharSequence is not empty and not null

isBlank

public static boolean isBlank(String s)
Checks if a String is blank. A blank string is one that is null, empty, or when trimmed using String.trim() is empty.

Parameters:
s - the String to check, may be null
Returns:
true if the String is null, empty, or trims to empty.

isNotBlank

public static boolean isNotBlank(String s)
Checks if a String is not blank. The opposite of isBlank(String).

Parameters:
s - the String to check, may be null
Returns:
true if the String is non-null and has content after being trimmed.

trimToNull

public static String trimToNull(String str)

Removes control characters (char <= 32) from both ends of this String returning null if the String is empty ("") after the trim or if it is null.

The String is trimmed using String.trim(). Trim removes start and end characters <= 32.

 Strings.trimToNull(null)          = null
 Strings.trimToNull("")            = null
 Strings.trimToNull("     ")       = null
 Strings.trimToNull("abc")         = "abc"
 Strings.trimToNull("    abc    ") = "abc"
 

Copied from Apache Commons Lang org.apache.commons.lang3.StringUtils.trimToNull(String)

Parameters:
str - the String to be trimmed, may be null
Returns:
the trimmed String, null if only chars <= 32, empty or null String input

quote

public static String quote(String str)
Returns a quoted string.

Parameters:
str - a String
Returns:
'str'

dquote

public static String dquote(String str)
Returns a double quoted string.

Parameters:
str - a String
Returns:
"str"


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