StringUtils (sdn-apidoc 2.5.14 API)

java.lang.Object
- com.hp.util.StringUtils

```
public final class StringUtils
extends Object
```
Provides useful utilities revolving around strings.

Author:

Simon Hunt, Steve Britt, Thomas Vachuska

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static class StringUtils.Align
Enumeration for alignment.

Nested Classes
Modifier and Type	Class and Description
`static class`	`StringUtils.Align` Enumeration for alignment.

Field Summary

Fields
Modifier and Type	Field and Description
`static String`	`COMMA` The comma (",") character as a string.
`static String`	`DEFAULT_JOIN_DELIMITER` Default delimiter for the `join(java.util.Collection<?>)` methods.
`static String`	`EMPTY` The empty string.
`static String`	`EOL` The platform dependent line separator (new line character).
`static String`	`TAB` The tab character.
`static String`	`UNDERSCORE` The underscore character.
`static String`	`UTF8` String representing UTF-8 encoding (e.g.
`static String`	`ZERO` The zero ("0") character as a string.

Method Summary

Methods
Modifier and Type	Method and Description
`static String`	`columnize(String[] strings)` Formats the supplied strings so that they are arranged in neat columns; maximum line width is 78; space between columns is 2; no indent.
`static String`	`columnize(String[] strings, int maxWidth)` Formats the supplied strings so that they are arranged in neat columns; space between columns is 2; no indent.
`static String`	`columnize(String[] strings, int maxWidth, int colSpacing)` Formats the supplied strings so that they are arranged in neat columns, but with no indent.
`static String`	`columnize(String[] strings, int maxWidth, int colSpacing, int indent)` Formats the supplied strings so that they are arranged in neat columns.
`static String`	`commaSeparated(Collection<?> items)` Returns a comma-separated string of the items in the collection.
`static String`	`concat(Object... values)` Concatenates an array of objects using a StringBuilder and its `append()` method.
`static String`	`emptyIsNull(String s)` Convert the given string to null, if it is already null or is empty.
`static boolean`	`equals(String one, String two)` Determine if two Strings, considering nulls to be identical, are equal.
`static String`	`format(String fmt, Object... o)` A simple string formatter that replaces each occurrence of `{}` in the format string with the string representation of each of the subsequent, optional arguments.
`static String`	`fromCamelCase(String cc)` This method expects an input string consisting of letters and digits in "camelCase" (the standard format for variable names), and converts it to uppercase letters with underscore delimiters between the words.
`static String`	`getFileContents(String path, ClassLoader classLoader)` Read in the contents of a text file from the given path.
`static boolean`	`isAlphaNumeric(String value)` This predicate returns true if the specified string is alpha numeric; that is to say, if it begins with a letter and consists only of letters, numbers and underscores.
`static boolean`	`isAlphaNumeric(String value, boolean allowUnderscores)` This predicate returns true if the specified string is alpha numeric; that is to say, if it begins with a letter and consists only of letters and numbers.
`static boolean`	`isEmpty(String value)` This predicate returns true if the specified parameter is null, or consists only of whitespace.
`static boolean`	`isIntegerZeroTo255(String value)` This predicate returns true if the specified string, when converted to an int, lies in the range 0 - 255.
`static boolean`	`isStandardIdentifier(String id)` This predicate returns true if the supplied string matches the regular expression defined for general identifiers.
`static String`	`join(Collection<?> values)` Joins a collection of objects' toString() values into a single string, using the default delimiter of ", " (comma-space).
`static String`	`join(Collection<?> values, String delim)` Joins a collection of objects' toString() values into a single string, using the given delimiter.
`static String`	`join(Object[] values)` Joins an array of objects' toString() values into a single string, using the default delimiter of ", " (comma-space).
`static String`	`join(Object[] values, String delim)` Joins an array of objects' toString() values into a single string, using the given delimiter.
`static String`	`normalizeEOL(String string)` Normalizes any compound line breaks (\r\n or \n\r) to only \n.
`static String`	`nullIsEmpty(String s)` Convert the given string to an empty string, if it is null.
`static String`	`pad(String what, int width)` Pads a field to the specified field width.
`static String`	`pad(String what, int width, char with)` Pads a field to the specified field width.
`static String`	`pad(String what, int width, char with, StringUtils.Align align)` Pads a field to the specified field width.
`static String`	`pad(String what, int width, char with, StringUtils.Align align, boolean noTruncate)` Pads a field to the specified field width.
`static String`	`pad(String what, int width, StringUtils.Align align)` Pads a field to the specified field width.
`static int`	`parseHex(String hex, int fallback)` Returns either the correctly parsed hex value (as an int) or the supplied fallback value.
`static int`	`parseInt(String value, int fallback)` Returns either the correctly parsed int value or the supplied fallback value.
`static String`	`quoted(String value)` Returns the given value wrapped in double-quote characters (") if the value is not null, or the string `"null"` if it is null.
`static String`	`safeToString(Object o)` Safely invokes `toString` on the specified entity and returns the result, unless the specified object is null, in which case it will return null.
`static String`	`spaces(int length)` Returns a string of spaces of the specified length.
`static String`	`stripCommentLines(String s)` Removes all lines that begin with the '#' character.
`static String`	`toCamelCase(Enum<?> e)` A convenience overloaded method for `toCamelCase(String)` which takes enumeration constants as the parameter.
`static String`	`toCamelCase(String s)` This method expects an input string consisting of uppercase letters, digits, and underscores (the standard format for constant names), and converts it to "camelCase".
`static String`	`toCamelCase(String prefix, Enum<?> e)` A convenience overloaded method for `toCamelCase(String, String)`, which uses `e.name()`.
`static String`	`toCamelCase(String prefix, String s)` This method expects a string consisting of uppercase letters, digits, and underscores (the standard format for constant names), and converts it to "camelCase".
`static String`	`trimmedEmptyIsNull(String s)` Convert the given string to null, if it is already null or is empty if trimmed.
`static String`	`trimPunct(String value)` Removes any punctuation in the passed in string.
`static String`	`trimPunctAndSpaceWith(String value, String replace)` Removes any punctuation and whitespace in the passed in string.
`static void`	`validateStandardIdentifier(String id)` This method checks the supplied string to see that it matches the regular expression defined for general identifiers.
`static String`	`zeroFill(int value, int fieldWidth)` Returns a zero-filled string.

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

- Field Detail
  - EOL
```
public static final String EOL
```
    The platform dependent line separator (new line character).
  - TAB
```
public static final String TAB
```
    The tab character.
    
    See Also:
    Constant Field Values
  - EMPTY
```
public static final String EMPTY
```
    The empty string.
    
    See Also:
    Constant Field Values
  - UNDERSCORE
```
public static final String UNDERSCORE
```
    The underscore character.
    
    See Also:
    Constant Field Values
  - ZERO
```
public static final String ZERO
```
    The zero ("0") character as a string.
    
    See Also:
    Constant Field Values
  - COMMA
```
public static final String COMMA
```
    The comma (",") character as a string.
    
    See Also:
    Constant Field Values
  - UTF8
```
public static final String UTF8
```
    String representing UTF-8 encoding (e.g. String.getBytes(UTF8))
    
    See Also:
    Constant Field Values
  - DEFAULT_JOIN_DELIMITER
```
public static final String DEFAULT_JOIN_DELIMITER
```
    Default delimiter for the join(java.util.Collection<?>) methods.
    
    See Also:
    Constant Field Values
- Method Detail
  - isEmpty
```
public static boolean isEmpty(String value)
```
    This predicate returns true if the specified parameter is null, or consists only of whitespace.
    
    Parameters:
    value - the string value to test
    
    Returns:
    true if the value is null, or empty
  - safeToString
```
public static String safeToString(Object o)
```
    Safely invokes toString on the specified entity and returns the result, unless the specified object is null, in which case it will return null.
    
    Parameters:
    o - object on which to invoke toString
    
    Returns:
    result of o.toString() invocation or null if the object is null
  - isAlphaNumeric
```
public static boolean isAlphaNumeric(String value,
                     boolean allowUnderscores)
```
    This predicate returns true if the specified string is alpha numeric; that is to say, if it begins with a letter and consists only of letters and numbers. Underscores are allowed if the second parameter is set true.
    
    Parameters:
    value - the string value to test
    allowUnderscores - if true, underscores are allowed
    
    Returns:
    true if the value is alphanumeric
    
    Throws:
    
    NullPointerException - if value is null
  - isAlphaNumeric
```
public static boolean isAlphaNumeric(String value)
```
    This predicate returns true if the specified string is alpha numeric; that is to say, if it begins with a letter and consists only of letters, numbers and underscores.
    
    Parameters:
    value - the string value to test
    
    Returns:
    true if the value is alphanumeric
    
    Throws:
    
    NullPointerException - if value is null
  - quoted
```
public static String quoted(String value)
```
    Returns the given value wrapped in double-quote characters (") if the value is not null, or the string "null" if it is null.
    
    Parameters:
    value - the value
    
    Returns:
    the string quoted (if not null), or "null"
  - toCamelCase
```
public static String toCamelCase(Enum<?> e)
```
    A convenience overloaded method for toCamelCase(String) which takes enumeration constants as the parameter.
    
    Parameters:
    e - the enum constant
    
    Returns:
    the name of the enum constant, camel-cased
  - toCamelCase
```
public static String toCamelCase(String s)
```
    This method expects an input string consisting of uppercase letters, digits, and underscores (the standard format for constant names), and converts it to "camelCase".
    For example, "LORD_OF_THE_RINGS" becomes "lordOfTheRings".
    
    Parameters:
    s - the uppercase words delimited by underscores input string
    
    Returns:
    the input string converted to camelCase
    
    Throws:
    
    NullPointerException - if the parameter is null
    
    IllegalArgumentException - if s has unexpected (or no) characters in it
  - toCamelCase
```
public static String toCamelCase(String prefix,
                 Enum<?> e)
```
    A convenience overloaded method for toCamelCase(String, String), which uses e.name().
    
    Parameters:
    prefix - optional prefix
    e - the enum constant
    
    Returns:
    the name of the enum constant, camel-cased
  - toCamelCase
```
public static String toCamelCase(String prefix,
                 String s)
```
    This method expects a string consisting of uppercase letters, digits, and underscores (the standard format for constant names), and converts it to "camelCase". If a prefix is specified, i.e. is not null or empty string, it will be prepended as-is.
    For example:
```
 "LORD_OF_THE_RINGS" --> "lordOfTheRings"
 "LORD_OF_THE_RINGS" and prefix "prequelTo" --> "prequelToLordOfTheRings"
 
```
    Parameters:
    prefix - optional prefix
    s - the uppercase words delimited by underscores input string
    
    Returns:
    the input string converted to camelCase
    
    Throws:
    
    NullPointerException - if the parameter is null
    
    IllegalArgumentException - if s has unexpected (or no) characters in it
  - fromCamelCase
```
public static String fromCamelCase(String cc)
```
    This method expects an input string consisting of letters and digits in "camelCase" (the standard format for variable names), and converts it to uppercase letters with underscore delimiters between the words.
    For example, "lordOfTheRings" becomes "LORD_OF_THE_RINGS".
    
    Parameters:
    cc - the camelCase input string
    
    Returns:
    the input string converted to uppercase words delimited by underscores
    
    Throws:
    
    NullPointerException - if the parameter is null
    
    IllegalArgumentException - if s has unexpected (or no) characters in it
  - isIntegerZeroTo255
```
public static boolean isIntegerZeroTo255(String value)
```
    This predicate returns true if the specified string, when converted to an int, lies in the range 0 - 255. Leading zeroes are allowed.
    
    Parameters:
    value - the string value to test
    
    Returns:
    true if the value is "0" - "255"
    
    Throws:
    
    NullPointerException - if value is null
  - isStandardIdentifier
```
public static boolean isStandardIdentifier(String id)
```
    This predicate returns true if the supplied string matches the regular expression defined for general identifiers. That is to say, the string starts with letter, and is followed by zero or more letters, numbers, underscores, and/or dots.
    
    Parameters:
    id - the identifier
    
    Returns:
    true if it is well-formed
  - validateStandardIdentifier
```
public static void validateStandardIdentifier(String id)
```
    This method checks the supplied string to see that it matches the regular expression defined for general identifiers. That is to say, the string starts with letter, and is followed by zero or more letters, numbers, underscores, and/or dots. If it matches, the method silently returns. If it does not match, an exception is thrown.
    
    Parameters:
    id - the identifier
    
    Throws:
    
    IllegalArgumentException - if the string does not match the pattern for standard identifiers.
  - equals
```
public static boolean equals(String one,
             String two)
```
    Determine if two Strings, considering nulls to be identical, are equal.
    
    Parameters:
    one - the first String to compare
    two - the second String to compare
    
    Returns:
    true if the Strings are identical, including if both are null, and false otherwise
  - parseHex
```
public static int parseHex(String hex,
           int fallback)
```
    Returns either the correctly parsed hex value (as an int) or the supplied fallback value.
    
    Parameters:
    hex - String to parse as a hex value
    fallback - The int to return if the supplied hex string is invalid
    
    Returns:
    the hex value
  - parseInt
```
public static int parseInt(String value,
           int fallback)
```
    Returns either the correctly parsed int value or the supplied fallback value.
    
    Parameters:
    value - String to parse as an int
    fallback - The int to return if the supplied string is invalid
    
    Returns:
    the int value
  - zeroFill
```
public static String zeroFill(int value,
              int fieldWidth)
```
    Returns a zero-filled string. For example:
```
 StringUtils.zeroFill(45, 6);
 
```
    returns the string "000045".
    Parameters:
    value - the value
    fieldWidth - the field width
    
    Returns:
    the zero filled string
  - format
```
public static String format(String fmt,
            Object... o)
```
    A simple string formatter that replaces each occurrence of {} in the format string with the string representation of each of the subsequent, optional arguments. For example:
```
     StringUtils.format("{} => {}", "Foo", 123);
     // returns "Foo => 123"
 
```
    Parameters:
    fmt - the format string
    o - arguments to be inserted into the output string
    
    Returns:
    a formatted string
  - columnize
```
public static String columnize(String[] strings,
               int maxWidth,
               int colSpacing,
               int indent)
```
    Formats the supplied strings so that they are arranged in neat columns.
    
    Parameters:
    strings - the array of strings to format
    maxWidth - the maximum number of characters any single line can be
    colSpacing - the number of spaces between columns
    indent - number of spaces to indent the whole thing by
    
    Returns:
    a string (with embedded newlines) that is the columnized result
  - columnize
```
public static String columnize(String[] strings,
               int maxWidth,
               int colSpacing)
```
    Formats the supplied strings so that they are arranged in neat columns, but with no indent.
    
    Parameters:
    strings - the array of strings to format
    maxWidth - the maximum number of characters any single line can be
    colSpacing - the number of spaces between columns
    
    Returns:
    the columnized strings
  - columnize
```
public static String columnize(String[] strings,
               int maxWidth)
```
    Formats the supplied strings so that they are arranged in neat columns; space between columns is 2; no indent.
    
    Parameters:
    strings - the array of strings to format
    maxWidth - the maximum number of characters any single line can be
    
    Returns:
    the columnized strings
  - columnize
```
public static String columnize(String[] strings)
```
    Formats the supplied strings so that they are arranged in neat columns; maximum line width is 78; space between columns is 2; no indent.
    
    Parameters:
    strings - the array of strings to format
    
    Returns:
    the columnized strings
  - pad
```
public static String pad(String what,
         int width,
         char with,
         StringUtils.Align align,
         boolean noTruncate)
```
    Pads a field to the specified field width. If what is longer than width, it is truncated, unless the noTruncate flag is set true.
    
    Parameters:
    what - the string to be padded
    width - the width of the padded (truncated) field
    with - the character to pad with
    align - the alignment
    noTruncate - do not truncate the string if it is longer than width
    
    Returns:
    the padded string
  - pad
```
public static String pad(String what,
         int width,
         char with,
         StringUtils.Align align)
```
    Pads a field to the specified field width. If what is longer than width, it is truncated.
    
    Parameters:
    what - the string to be padded
    width - the width of the padded (truncated) field
    with - the character to pad with
    align - the alignment
    
    Returns:
    the padded string
  - pad
```
public static String pad(String what,
         int width,
         char with)
```
    Pads a field to the specified field width. If what is longer than width, it is truncated. The text is LEFT justified.
    
    Parameters:
    what - the string to be padded
    width - the width of the padded (truncated) field
    with - the character to pad with
    
    Returns:
    the padded string
  - pad
```
public static String pad(String what,
         int width,
         StringUtils.Align align)
```
    Pads a field to the specified field width. If what is longer than width, it is truncated. Space is used as the padding character.
    
    Parameters:
    what - the string to be padded
    width - the width of the padded (truncated) field
    align - one of LEFT, CENTER or RIGHT
    
    Returns:
    the padded string
  - pad
```
public static String pad(String what,
         int width)
```
    Pads a field to the specified field width. If what is longer than width, it is truncated. The text is LEFT justified. Space is used as the padding character.
    
    Parameters:
    what - the string to be padded
    width - the width of the padded (truncated) field
    
    Returns:
    the padded string
  - spaces
```
public static String spaces(int length)
```
    Returns a string of spaces of the specified length.
    
    Parameters:
    length - the length
    
    Returns:
    a string of spaces
  - commaSeparated
```
public static String commaSeparated(Collection<?> items)
```
    Returns a comma-separated string of the items in the collection. The individual tokens within the string are produced using Object#toString() on each item in the collection.
    
    Parameters:
    items - collection of items
    
    Returns:
    comma-separated string of items in the collection; empty string if the collection is empty; null if the collection is null
  - emptyIsNull
```
public static String emptyIsNull(String s)
```
    Convert the given string to null, if it is already null or is empty.
    
    Parameters:
    s - string to be verified
    
    Returns:
    null if the string is null or empty; otherwise the unmodified string
  - trimmedEmptyIsNull
```
public static String trimmedEmptyIsNull(String s)
```
    Convert the given string to null, if it is already null or is empty if trimmed.
    
    Parameters:
    s - string to be verified
    
    Returns:
    null if the string is null or empty; otherwise the unmodified string
  - nullIsEmpty
```
public static String nullIsEmpty(String s)
```
    Convert the given string to an empty string, if it is null.
    
    Parameters:
    s - string to be verified
    
    Returns:
    empty string if the string is null; otherwise the unmodified string
  - trimPunct
```
public static String trimPunct(String value)
```
    Removes any punctuation in the passed in string.
    
    Parameters:
    value - the original string value that may contain punctuation
    
    Returns:
    true new string with the punctuation removed
    
    Throws:
    
    NullPointerException - if value is null
  - trimPunctAndSpaceWith
```
public static String trimPunctAndSpaceWith(String value,
                           String replace)
```
    Removes any punctuation and whitespace in the passed in string.
    
    Parameters:
    value - the original string value that may contain punctuation
    replace - string to be replaced instead of punctuation and white space
    
    Returns:
    true new string with the punctuation removed
    
    Throws:
    
    NullPointerException - if value is null
  - join
```
public static String join(Collection<?> values)
```
    Joins a collection of objects' toString() values into a single string, using the default delimiter of ", " (comma-space).
    
    Parameters:
    values - the values
    
    Returns:
    the delimiter-separated string
  - join
```
public static String join(Object[] values)
```
    Joins an array of objects' toString() values into a single string, using the default delimiter of ", " (comma-space).
    
    Parameters:
    values - the values
    
    Returns:
    the delimiter-separated string
  - join
```
public static String join(Collection<?> values,
          String delim)
```
    Joins a collection of objects' toString() values into a single string, using the given delimiter. If the collection is null, null is returned.
    
    Parameters:
    values - the values
    delim - the delimiter
    
    Returns:
    the delimiter-separated string
  - join
```
public static String join(Object[] values,
          String delim)
```
    Joins an array of objects' toString() values into a single string, using the given delimiter. If the array is null, null is returned.
    
    Parameters:
    values - the values
    delim - the delimiter
    
    Returns:
    the delimiter-separated string
  - concat
```
public static String concat(Object... values)
```
    Concatenates an array of objects using a StringBuilder and its append() method. This convenience method reduces something like:
```
 String s = new StringBuilder().append(e1).append(e2).append(e3).toString();
 
```
    to
```
 String s = StringUtils.concat(e1, e2, e3);
 
```
    Parameters:
    values - the values to concatenate
    
    Returns:
    the concatentated string
  - normalizeEOL
```
public static String normalizeEOL(String string)
```
    Normalizes any compound line breaks (\r\n or \n\r) to only \n.
    
    Parameters:
    string - string to be normalized
    
    Returns:
    normalized string
  - stripCommentLines
```
public static String stripCommentLines(String s)
```
    Removes all lines that begin with the '#' character.
    
    Parameters:
    s - the multiline input
    
    Returns:
    multiline output with "comment" lines removed
  - getFileContents
```
public static String getFileContents(String path,
                     ClassLoader classLoader)
                              throws IOException
```
    Read in the contents of a text file from the given path. If the resource cannot be found, null is returned.
    
    Parameters:
    path - path of resource containing the data
    classLoader - class-loader to be used for locating resource
    
    Returns:
    the contents of the file as a string
    
    Throws:
    
    IOException - if there is a problem reading the file.

Class StringUtils

Nested Class Summary

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

EOL

TAB

EMPTY

UNDERSCORE

ZERO

COMMA

UTF8

DEFAULT_JOIN_DELIMITER

Method Detail

isEmpty

safeToString

isAlphaNumeric

isAlphaNumeric

quoted

toCamelCase

toCamelCase

toCamelCase

toCamelCase

fromCamelCase

isIntegerZeroTo255

isStandardIdentifier

validateStandardIdentifier

equals

parseHex

parseInt

zeroFill

format

columnize

columnize

columnize

columnize

pad

pad

pad

pad

pad

spaces

commaSeparated

emptyIsNull

trimmedEmptyIsNull

nullIsEmpty

trimPunct

trimPunctAndSpaceWith

join

join

join

join

concat

normalizeEOL

stripCommentLines

getFileContents