StringUtils (nd4j-common 1.0.0-beta2 API)

java.lang.Object
- org.nd4j.util.StringUtils

```
public class StringUtils
extends Object
```
General string utils - adapted from Apache Hadoop StringUtils, with modifications

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static class`	`StringUtils.TraditionalBinaryPrefix` The traditional binary prefixes, kilo, mega, ..., exa, which can be represented by a 64-bit integer.

Field Summary

Fields
Modifier and Type Field and Description

static char COMMA

static String[] emptyStringArray

static char ESCAPE_CHAR

Fields
Modifier and Type	Field and Description
`static char`	`COMMA`
`static String[]`	`emptyStringArray`
`static char`	`ESCAPE_CHAR`

Constructor Summary

Constructors
Constructor and Description

StringUtils()

Constructors
Constructor and Description
`StringUtils()`

Method Summary

All Methods Static Methods Concrete Methods Deprecated Methods
Modifier and Type	Method and Description
`static String`	`arrayToString(String[] strs)` Given an array of strings, return a comma-separated list of its elements.
`static String`	`byteDesc(long len)`
`static String`	`byteToHexString(byte b)` Convert a byte to a hex string.
`static String`	`byteToHexString(byte[] bytes)` Same as byteToHexString(bytes, 0, bytes.length).
`static String`	`byteToHexString(byte[] bytes, int start, int end)` Given an array of bytes it will convert the bytes to a hex string representation of the bytes
`static String`	`camelize(String s)` Convert SOME_STUFF to SomeStuff
`static boolean`	`equalsIgnoreCase(String s1, String s2)` Compare strings locale-freely by using String#equalsIgnoreCase.
`static String`	`escapeHTML(String string)` Escapes HTML Special characters present in the string.
`static String`	`escapeString(String str)` Escape commas in the string using the default escape char
`static String`	`escapeString(String str, char escapeChar, char charToEscape)` Escape `charToEscape` in the string with the escape char `escapeChar`
`static String`	`escapeString(String str, char escapeChar, char[] charsToEscape)`
`static int`	`findNext(String str, char separator, char escapeChar, int start, StringBuilder split)` Finds the first occurrence of the separator character ignoring the escaped separators starting from the index.
`static String`	`format(String format, Object... objects)` The same as String.format(Locale.ENGLISH, format, objects).
`static String`	`formatPercent(double fraction, int decimalPlaces)` Format a percentage for presentation to the user.
`static String`	`formatTime(long timeDiff)` Given the time in long milliseconds, returns a String in the format Xhrs, Ymins, Z sec.
`static String`	`formatTimeDiff(long finishTime, long startTime)` Given a finish and start time in long milliseconds, returns a String in the format Xhrs, Ymins, Z sec, for the time difference between two times.
`static String`	`formatTimeSortable(long timeDiff)` Given the time in long milliseconds, returns a String in the sortable format Xhrs, Ymins, Zsec.
`static String`	`getFormattedTimeWithDiff(String formattedFinishTime, long finishTime, long startTime)` Formats time in ms and appends difference (finishTime - startTime) as returned by formatTimeDiff().
`static String`	`getStackTrace(Thread t)` Get stack trace for a given thread.
`static Collection<String>`	`getStringCollection(String str)` Returns a collection of strings.
`static Collection<String>`	`getStringCollection(String str, String delim)` Returns a collection of strings.
`static String[]`	`getStrings(String str)` Returns an arraylist of strings.
`static String[]`	`getStrings(String str, String delim)` Returns an arraylist of strings.
`static Collection<String>`	`getTrimmedStringCollection(String str)` Splits a comma separated value `String`, trimming leading and trailing whitespace on each value.
`static String[]`	`getTrimmedStrings(String str)` Splits a comma or newline separated value `String`, trimming leading and trailing whitespace on each value.
`static byte[]`	`hexStringToByte(String hex)` Given a hexstring this will return the byte array corresponding to the string
`static String`	`humanReadableInt(long number)` Deprecated. use `StringUtils.TraditionalBinaryPrefix.long2String(long, String, int)`.
`static boolean`	`isAlpha(String str)` Checks if the String contains only unicode letters.
`static String`	`join(char separator, Iterable<?> strings)` Concatenates strings, using whitespaces as separator.
`static String`	`join(CharSequence separator, Iterable<?> strings)` Concatenates strings, using a separator.
`static String`	`join(CharSequence separator, String[] strings)` Concatenates strings, using a separator.
`static String`	`join(char separator, String[] strings)`
`static String`	`join(Iterable<String> strings)` Concatenates strings, using whitespaces as separator.
`static String`	`limitDecimalTo2(double d)` Deprecated. use StringUtils.format("%.2f", d).
`static String`	`replaceTokens(String template, Pattern pattern, Map<String,String> replacements)` Matches a template string against a pattern, replaces matched tokens with the supplied replacements, and returns the result.
`static String`	`simpleHostname(String fullHostname)` Given a full hostname, return the word upto the first dot.
`static String[]`	`split(String str)` Split a string using the default separator
`static String[]`	`split(String str, char separator)` Split a string using the given separator, with no escaping performed.
`static String[]`	`split(String str, char escapeChar, char separator)` Split a string using the given separator
`static String[]`	`splitOnCharWithQuoting(String s, char splitChar, char quoteChar, char escapeChar)` This function splits the String s into multiple Strings using the splitChar.
`static String`	`stringifyException(Throwable e)` Make a string representation of the exception.
`static TimeUnit`	`stringToTimeUnit(String str)`
`static URI[]`	`stringToURI(String[] str)`
`static String`	`timeUnitToString(long time, TimeUnit unit)`
`static String`	`toLowerCase(String str)` Converts all of the characters in this String to lower case with Locale.ENGLISH.
`static String`	`toUpperCase(String str)` Converts all of the characters in this String to upper case with Locale.ENGLISH.
`static String`	`unEscapeString(String str)` Unescape commas in the string using the default escape char
`static String`	`unEscapeString(String str, char escapeChar, char charToEscape)` Unescape `charToEscape` in the string with the escape char `escapeChar`
`static String`	`unEscapeString(String str, char escapeChar, char[] charsToEscape)`
`static String`	`uriToString(URI[] uris)`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - emptyStringArray
```
public static final String[] emptyStringArray
```
  - COMMA
```
public static final char COMMA
```
    See Also:
    
    Constant Field Values
  - ESCAPE_CHAR
```
public static final char ESCAPE_CHAR
```
    See Also:
    
    Constant Field Values
- Constructor Detail
  - StringUtils
```
public StringUtils()
```
- Method Detail
  - stringifyException
```
public static String stringifyException(Throwable e)
```
    Make a string representation of the exception.
    
    Parameters:
    
    e - The exception to stringify
    
    Returns:
    
    A string with exception name and call stack.
  - simpleHostname
```
public static String simpleHostname(String fullHostname)
```
    Given a full hostname, return the word upto the first dot.
    
    Parameters:
    
    fullHostname - the full hostname
    
    Returns:
    
    the hostname to the first dot
  - humanReadableInt
```
@Deprecated
public static String humanReadableInt(long number)
```
    Deprecated. use StringUtils.TraditionalBinaryPrefix.long2String(long, String, int).
    
    Given an integer, return a string that is in an approximate, but human readable format.
    
    Parameters:
    
    number - the number to format
    
    Returns:
    
    a human readable form of the integer
  - format
```
public static String format(String format,
                            Object... objects)
```
    The same as String.format(Locale.ENGLISH, format, objects).
  - formatPercent
```
public static String formatPercent(double fraction,
                                   int decimalPlaces)
```
    Format a percentage for presentation to the user.
    
    Parameters:
    
    fraction - the percentage as a fraction, e.g. 0.1 = 10%
    
    decimalPlaces - the number of decimal places
    
    Returns:
    
    a string representation of the percentage
  - arrayToString
```
public static String arrayToString(String[] strs)
```
    Given an array of strings, return a comma-separated list of its elements.
    
    Parameters:
    
    strs - Array of strings
    
    Returns:
    
    Empty string if strs.length is 0, comma separated list of strings otherwise
  - byteToHexString
```
public static String byteToHexString(byte[] bytes,
                                     int start,
                                     int end)
```
    Given an array of bytes it will convert the bytes to a hex string representation of the bytes
    
    Parameters:
    
    bytes -
    
    start - start index, inclusively
    
    end - end index, exclusively
    
    Returns:
    
    hex string representation of the byte array
  - byteToHexString
```
public static String byteToHexString(byte[] bytes)
```
    Same as byteToHexString(bytes, 0, bytes.length).
  - byteToHexString
```
public static String byteToHexString(byte b)
```
    Convert a byte to a hex string.
    
    Parameters:
    
    b - byte
    
    Returns:
    
    byte's hex value as a String
    
    See Also:
    
    byteToHexString(byte[]), byteToHexString(byte[], int, int)
  - hexStringToByte
```
public static byte[] hexStringToByte(String hex)
```
    Given a hexstring this will return the byte array corresponding to the string
    
    Parameters:
    
    hex - the hex String array
    
    Returns:
    
    a byte array that is a hex string representation of the given string. The size of the byte array is therefore hex.length/2
  - uriToString
```
public static String uriToString(URI[] uris)
```
    Parameters:
    
    uris -
  - stringToURI
```
public static URI[] stringToURI(String[] str)
```
    Parameters:
    
    str - The string array to be parsed into an URI array.
    
    Returns:
    
    null if str is null, else the URI array equivalent to str.
    
    Throws:
    
    IllegalArgumentException - If any string in str violates RFC 2396.
  - formatTimeDiff
```
public static String formatTimeDiff(long finishTime,
                                    long startTime)
```
    Given a finish and start time in long milliseconds, returns a String in the format Xhrs, Ymins, Z sec, for the time difference between two times. If finish time comes before start time then negative valeus of X, Y and Z wil return.
    
    Parameters:
    
    finishTime - finish time
    
    startTime - start time
  - formatTime
```
public static String formatTime(long timeDiff)
```
    Given the time in long milliseconds, returns a String in the format Xhrs, Ymins, Z sec.
    
    Parameters:
    
    timeDiff - The time difference to format
  - formatTimeSortable
```
public static String formatTimeSortable(long timeDiff)
```
    Given the time in long milliseconds, returns a String in the sortable format Xhrs, Ymins, Zsec. X, Y, and Z are always two-digit. If the time is more than 100 hours ,it is displayed as 99hrs, 59mins, 59sec.
    
    Parameters:
    
    timeDiff - The time difference to format
  - getFormattedTimeWithDiff
```
public static String getFormattedTimeWithDiff(String formattedFinishTime,
                                              long finishTime,
                                              long startTime)
```
    Formats time in ms and appends difference (finishTime - startTime) as returned by formatTimeDiff(). If finish time is 0, empty string is returned, if start time is 0 then difference is not appended to return value.
    
    Parameters:
    
    formattedFinishTime - formattedFinishTime to use
    
    finishTime - finish time
    
    startTime - start time
    
    Returns:
    
    formatted value.
  - getStrings
```
public static String[] getStrings(String str)
```
    Returns an arraylist of strings.
    
    Parameters:
    
    str - the comma separated string values
    
    Returns:
    
    the arraylist of the comma separated string values
  - getStrings
```
public static String[] getStrings(String str,
                                  String delim)
```
    Returns an arraylist of strings.
    
    Parameters:
    
    str - the string values
    
    delim - delimiter to separate the values
    
    Returns:
    
    the arraylist of the separated string values
  - getStringCollection
```
public static Collection<String> getStringCollection(String str)
```
    Returns a collection of strings.
    
    Parameters:
    
    str - comma separated string values
    
    Returns:
    
    an ArrayList of string values
  - getStringCollection
```
public static Collection<String> getStringCollection(String str,
                                                     String delim)
```
    Returns a collection of strings.
    
    Parameters:
    
    str - String to parse
    
    delim - delimiter to separate the values
    
    Returns:
    
    Collection of parsed elements.
  - getTrimmedStringCollection
```
public static Collection<String> getTrimmedStringCollection(String str)
```
    Splits a comma separated value String, trimming leading and trailing whitespace on each value. Duplicate and empty values are removed.
    
    Parameters:
    
    str - a comma separated with values, may be null
    
    Returns:
    
    a Collection of String values, empty Collection if null String input
  - getTrimmedStrings
```
public static String[] getTrimmedStrings(String str)
```
    Splits a comma or newline separated value String, trimming leading and trailing whitespace on each value.
    
    Parameters:
    
    str - a comma or newline separated String with values, may be null
    
    Returns:
    
    an array of String values, empty array if null String input
  - split
```
public static String[] split(String str)
```
    Split a string using the default separator
    
    Parameters:
    
    str - a string that may have escaped separator
    
    Returns:
    
    an array of strings
  - split
```
public static String[] split(String str,
                             char escapeChar,
                             char separator)
```
    Split a string using the given separator
    
    Parameters:
    
    str - a string that may have escaped separator
    
    escapeChar - a char that be used to escape the separator
    
    separator - a separator char
    
    Returns:
    
    an array of strings
  - split
```
public static String[] split(String str,
                             char separator)
```
    Split a string using the given separator, with no escaping performed.
    
    Parameters:
    
    str - a string to be split. Note that this may not be null.
    
    separator - a separator char
    
    Returns:
    
    an array of strings
  - findNext
```
public static int findNext(String str,
                           char separator,
                           char escapeChar,
                           int start,
                           StringBuilder split)
```
    Finds the first occurrence of the separator character ignoring the escaped separators starting from the index. Note the substring between the index and the position of the separator is passed.
    
    Parameters:
    
    str - the source string
    
    separator - the character to find
    
    escapeChar - character used to escape
    
    start - from where to search
    
    split - used to pass back the extracted string
  - splitOnCharWithQuoting
```
public static String[] splitOnCharWithQuoting(String s,
                                              char splitChar,
                                              char quoteChar,
                                              char escapeChar)
```
    This function splits the String s into multiple Strings using the splitChar. However, it provides an quoting facility: it is possible to quote strings with the quoteChar. If the quoteChar occurs within the quotedExpression, it must be prefaced by the escapeChar
    
    Parameters:
    
    s - The String to split
    
    splitChar -
    
    quoteChar -
    
    Returns:
    
    An array of Strings that s is split into
  - escapeString
```
public static String escapeString(String str)
```
    Escape commas in the string using the default escape char
    
    Parameters:
    
    str - a string
    
    Returns:
    
    an escaped string
  - escapeString
```
public static String escapeString(String str,
                                  char escapeChar,
                                  char charToEscape)
```
    Escape charToEscape in the string with the escape char escapeChar
    
    Parameters:
    
    str - string
    
    escapeChar - escape char
    
    charToEscape - the char to be escaped
    
    Returns:
    
    an escaped string
  - escapeString
```
public static String escapeString(String str,
                                  char escapeChar,
                                  char[] charsToEscape)
```
    Parameters:
    
    charsToEscape - array of characters to be escaped
  - unEscapeString
```
public static String unEscapeString(String str)
```
    Unescape commas in the string using the default escape char
    
    Parameters:
    
    str - a string
    
    Returns:
    
    an unescaped string
  - unEscapeString
```
public static String unEscapeString(String str,
                                    char escapeChar,
                                    char charToEscape)
```
    Unescape charToEscape in the string with the escape char escapeChar
    
    Parameters:
    
    str - string
    
    escapeChar - escape char
    
    charToEscape - the escaped char
    
    Returns:
    
    an unescaped string
  - unEscapeString
```
public static String unEscapeString(String str,
                                    char escapeChar,
                                    char[] charsToEscape)
```
    Parameters:
    
    charsToEscape - array of characters to unescape
  - escapeHTML
```
public static String escapeHTML(String string)
```
    Escapes HTML Special characters present in the string.
    
    Parameters:
    
    string -
    
    Returns:
    
    HTML Escaped String representation
  - byteDesc
```
public static String byteDesc(long len)
```
    Returns:
    
    a byte description of the given long interger value.
  - limitDecimalTo2
```
@Deprecated
public static String limitDecimalTo2(double d)
```
    Deprecated. use StringUtils.format("%.2f", d).
  - join
```
public static String join(CharSequence separator,
                          Iterable<?> strings)
```
    Concatenates strings, using a separator.
    
    Parameters:
    
    separator - Separator to join with.
    
    strings - Strings to join.
  - join
```
public static String join(Iterable<String> strings)
```
    Concatenates strings, using whitespaces as separator.
    
    Parameters:
    
    strings - Strings to join.
  - join
```
public static String join(char separator,
                          Iterable<?> strings)
```
    Concatenates strings, using whitespaces as separator.
    
    Parameters:
    
    strings - Strings to join.
  - join
```
public static String join(CharSequence separator,
                          String[] strings)
```
    Concatenates strings, using a separator.
    
    Parameters:
    
    separator - to join with
    
    strings - to join
    
    Returns:
    
    the joined string
  - join
```
public static String join(char separator,
                          String[] strings)
```
  - camelize
```
public static String camelize(String s)
```
    Convert SOME_STUFF to SomeStuff
    
    Parameters:
    
    s - input string
    
    Returns:
    
    camelized string
  - replaceTokens
```
public static String replaceTokens(String template,
                                   Pattern pattern,
                                   Map<String,String> replacements)
```
    Matches a template string against a pattern, replaces matched tokens with the supplied replacements, and returns the result. The regular expression must use a capturing group. The value of the first capturing group is used to look up the replacement. If no replacement is found for the token, then it is replaced with the empty string. For example, assume template is "%foo%_%bar%_%baz%", pattern is "%(.*?)%", and replacements contains 2 entries, mapping "foo" to "zoo" and "baz" to "zaz". The result returned would be "zoo__zaz".
    
    Parameters:
    
    template - String template to receive replacements
    
    pattern - Pattern to match for identifying tokens, must use a capturing group
    
    replacements - Map mapping tokens identified by the capturing group to their replacement values
    
    Returns:
    
    String template with replacements
  - getStackTrace
```
public static String getStackTrace(Thread t)
```
    Get stack trace for a given thread.
  - toLowerCase
```
public static String toLowerCase(String str)
```
    Converts all of the characters in this String to lower case with Locale.ENGLISH.
    
    Parameters:
    
    str - string to be converted
    
    Returns:
    
    the str, converted to lowercase.
  - toUpperCase
```
public static String toUpperCase(String str)
```
    Converts all of the characters in this String to upper case with Locale.ENGLISH.
    
    Parameters:
    
    str - string to be converted
    
    Returns:
    
    the str, converted to uppercase.
  - equalsIgnoreCase
```
public static boolean equalsIgnoreCase(String s1,
                                       String s2)
```
    Compare strings locale-freely by using String#equalsIgnoreCase.
    
    Parameters:
    
    s1 - Non-null string to be converted
    
    s2 - string to be converted
    
    Returns:
    
    the str, converted to uppercase.
  - isAlpha
```
public static boolean isAlpha(String str)
```
    Checks if the String contains only unicode letters.
    
    null will return false. An empty String (length()=0) will return true.
```
 StringUtils.isAlpha(null)   = false
 StringUtils.isAlpha("")     = true
 StringUtils.isAlpha("  ")   = false
 StringUtils.isAlpha("abc")  = true
 StringUtils.isAlpha("ab2c") = false
 StringUtils.isAlpha("ab-c") = false
 
```
    Parameters:
    
    str - the String to check, may be null
    
    Returns:
    
    true if only contains letters, and is non-null
  - timeUnitToString
```
public static String timeUnitToString(long time,
                                      TimeUnit unit)
```
  - stringToTimeUnit
```
public static TimeUnit stringToTimeUnit(String str)
```

Class StringUtils

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

emptyStringArray

COMMA

ESCAPE_CHAR

Constructor Detail

StringUtils

Method Detail

stringifyException

simpleHostname

humanReadableInt

format

formatPercent

arrayToString

byteToHexString

byteToHexString

byteToHexString

hexStringToByte

uriToString

stringToURI

formatTimeDiff

formatTime

formatTimeSortable

getFormattedTimeWithDiff

getStrings

getStrings

getStringCollection

getStringCollection

getTrimmedStringCollection

getTrimmedStrings

split

split

split

findNext

splitOnCharWithQuoting

escapeString

escapeString

escapeString

unEscapeString

unEscapeString

unEscapeString

escapeHTML

byteDesc

limitDecimalTo2

join

join

join

join

join

camelize

replaceTokens

getStackTrace

toLowerCase

toUpperCase

equalsIgnoreCase

isAlpha

timeUnitToString

stringToTimeUnit