org.apache.logging.log4j.util

Class Strings

java.lang.Object

org.apache.logging.log4j.util.Strings

public final class Strings
extends Object

Consider this class private.

Field Summary

Fields

Modifier and Type	Field and Description
static String	EMPTY The empty string.

Method Summary

Modifier and Type	Method and Description
static boolean	isEmpty(CharSequence cs) Checks if a CharSequence is empty ("") or null.
static boolean	isNotEmpty(CharSequence cs) Checks if a CharSequence is not empty ("") and not null.
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

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