org.modeshape.common.util
Class StringUtil

java.lang.Object
  org.modeshape.common.util.StringUtil

@Immutable
public class StringUtil
extends Object

Utilities for string processing and manipulation.

Field Summary

static String[]

EMPTY_STRING_ARRAY

Method Summary

static String	combineLines(String[] lines) Combine the lines into a single string, using the new line character as the delimiter.
static String	combineLines(String[] lines, char separator) Combine the lines into a single string, using the supplied separator as the delimiter.
static String	createString(char charToRepeat, int numberOfRepeats) Create a new string containing the specified character repeated a specific number of times.
static String	createString(String pattern, Object... parameters) Create a string by substituting the parameters into all key occurrences in the supplied format.
static byte[]	fromHexString(String hexadecimal)
static String	getHexString(byte[] bytes) Get the hexadecimal string representation of the supplied byte array.
static String	getStackTrace(Throwable throwable) Get the stack trace of the supplied exception.
static boolean	isBlank(String str) Returns true if the given string is null or represents the empty string
static String	justifyCenter(String str, int width, char padWithChar) Center the contents of the string.
static String	justifyLeft(String str, int width, char padWithChar) Left justify the contents of the string, ensuring that the supplied string begins at the first character and that the resulting string is of the desired length.
protected static String	justifyLeft(String str, int width, char padWithChar, boolean trimWhitespace)
static String	justifyRight(String str, int width, char padWithChar) Right justify the contents of the string, ensuring that the string ends at the last character.
static String	normalize(String text) Removes leading and trailing whitespace from the supplied text, and reduces other consecutive whitespace characters to a single space.
static String	read(InputStream stream) Read and return the entire contents of the supplied InputStream.
static String	read(Reader reader) Read and return the entire contents of the supplied Reader.
static String	setLength(String original, int length, char padChar) Set the length of the string, padding with the supplied character if the supplied string is shorter than desired, or truncating the string if it is longer than desired.
static List<String>	splitLines(String content) Split the supplied content into lines, returning each line as an element in the returned list.
static String	truncate(Object obj, int maxLength) Truncate the supplied string to be no more than the specified length.
static String	truncate(Object obj, int maxLength, String suffix) Truncate the supplied string to be no more than the specified length.
static void	write(String content, OutputStream stream) Write the entire contents of the supplied string to the given stream.
static void	write(String content, Writer writer) Write the entire contents of the supplied string to the given writer.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

EMPTY_STRING_ARRAY

public static final String[] EMPTY_STRING_ARRAY

Method Detail

combineLines

public static String combineLines(String[] lines)

Combine the lines into a single string, using the new line character as the delimiter. This is compatible with splitLines(String).

Parameters:

lines - the lines to be combined

Returns:

the combined lines, or an empty string if there are no lines

combineLines

public static String combineLines(String[] lines,
                                  char separator)

Combine the lines into a single string, using the supplied separator as the delimiter.

Parameters:

lines - the lines to be combined

separator - the separator character

Returns:

the combined lines, or an empty string if there are no lines

splitLines

public static List<String> splitLines(String content)

Split the supplied content into lines, returning each line as an element in the returned list.

Parameters:

content - the string content that is to be split

Returns:

the list of lines; never null but may be an empty (unmodifiable) list if the supplied content is null or empty

createString

public static String createString(String pattern,
                                  Object... parameters)

Create a string by substituting the parameters into all key occurrences in the supplied format. The pattern consists of zero or more keys of the form {n}, where n is an integer starting at 1. Therefore, the first parameter replaces all occurrences of "{1}", the second parameter replaces all occurrences of "{2}", etc.

If any parameter is null, the corresponding key is replaced with the string "null". Therefore, consider using an empty string when keys are to be removed altogether.

If there are no parameters, this method does nothing and returns the supplied pattern as is.

Parameters:

pattern - the pattern

parameters - the parameters used to replace keys

Returns:

the string with all keys replaced (or removed)

createString

public static String createString(char charToRepeat,
                                  int numberOfRepeats)

Create a new string containing the specified character repeated a specific number of times.

Parameters:

charToRepeat - the character to repeat

numberOfRepeats - the number of times the character is to repeat in the result; must be greater than 0

Returns:

the resulting string

setLength

public static String setLength(String original,
                               int length,
                               char padChar)

Set the length of the string, padding with the supplied character if the supplied string is shorter than desired, or truncating the string if it is longer than desired. Unlike justifyLeft(String, int, char), this method does not remove leading and trailing whitespace.

Parameters:

original - the string for which the length is to be set; may not be null

length - the desired length; must be positive

padChar - the character to use for padding, if the supplied string is not long enough

Returns:

the string of the desired length

See Also:

justifyLeft(String, int, char)

justifyRight

public static String justifyRight(String str,
                                  int width,
                                  char padWithChar)

Right justify the contents of the string, ensuring that the string ends at the last character. If the supplied string is longer than the desired width, the leading characters are removed so that the last character in the supplied string at the last position. If the supplied string is shorter than the desired width, the padding character is inserted one or more times such that the last character in the supplied string appears as the last character in the resulting string and that the length matches that specified.

Parameters:

str - the string to be right justified; if null, an empty string is used

width - the desired width of the string; must be positive

padWithChar - the character to use for padding, if needed

Returns:

the right justified string

justifyLeft

public static String justifyLeft(String str,
                                 int width,
                                 char padWithChar)

Left justify the contents of the string, ensuring that the supplied string begins at the first character and that the resulting string is of the desired length. If the supplied string is longer than the desired width, it is truncated to the specified length. If the supplied string is shorter than the desired width, the padding character is added to the end of the string one or more times such that the length is that specified. All leading and trailing whitespace is removed.

Parameters:

str - the string to be left justified; if null, an empty string is used

width - the desired width of the string; must be positive

padWithChar - the character to use for padding, if needed

Returns:

the left justified string

See Also:

setLength(String, int, char)

justifyLeft

protected static String justifyLeft(String str,
                                    int width,
                                    char padWithChar,
                                    boolean trimWhitespace)

justifyCenter

public static String justifyCenter(String str,
                                   int width,
                                   char padWithChar)

Center the contents of the string. If the supplied string is longer than the desired width, it is truncated to the specified length. If the supplied string is shorter than the desired width, padding characters are added to the beginning and end of the string such that the length is that specified; one additional padding character is prepended if required. All leading and trailing whitespace is removed before centering.

Parameters:

str - the string to be left justified; if null, an empty string is used

width - the desired width of the string; must be positive

padWithChar - the character to use for padding, if needed

Returns:

the left justified string

See Also:

setLength(String, int, char)

truncate

public static String truncate(Object obj,
                              int maxLength)

Truncate the supplied string to be no more than the specified length. This method returns an empty string if the supplied object is null.

Parameters:

obj - the object from which the string is to be obtained using Object.toString().

maxLength - the maximum length of the string being returned

Returns:

the supplied string if no longer than the maximum length, or the supplied string truncated to be no longer than the maximum length (including the suffix)

Throws:

IllegalArgumentException - if the maximum length is negative

truncate

public static String truncate(Object obj,
                              int maxLength,
                              String suffix)

Truncate the supplied string to be no more than the specified length. This method returns an empty string if the supplied object is null.

Parameters:

obj - the object from which the string is to be obtained using Object.toString().

maxLength - the maximum length of the string being returned

suffix - the suffix that should be added to the content if the string must be truncated, or null if the default suffix of "..." should be used

Returns:

the supplied string if no longer than the maximum length, or the supplied string truncated to be no longer than the maximum length (including the suffix)

Throws:

IllegalArgumentException - if the maximum length is negative

read

public static String read(Reader reader)
                   throws IOException

Read and return the entire contents of the supplied Reader. This method always closes the reader when finished reading.

Parameters:

reader - the reader of the contents; may be null

Returns:

the contents, or an empty string if the supplied reader is null

Throws:

IOException - if there is an error reading the content

read

public static String read(InputStream stream)
                   throws IOException

Read and return the entire contents of the supplied InputStream. This method always closes the stream when finished reading.

Parameters:

stream - the streamed contents; may be null

Returns:

the contents, or an empty string if the supplied stream is null

Throws:

IOException - if there is an error reading the content

write

public static void write(String content,
                         OutputStream stream)
                  throws IOException

Write the entire contents of the supplied string to the given stream. This method always flushes and closes the stream when finished.

Parameters:

content - the content to write to the stream; may be null

stream - the stream to which the content is to be written

Throws:

IOException

IllegalArgumentException - if the stream is null

write

public static void write(String content,
                         Writer writer)
                  throws IOException

Write the entire contents of the supplied string to the given writer. This method always flushes and closes the writer when finished.

Parameters:

content - the content to write to the writer; may be null

writer - the writer to which the content is to be written

Throws:

IOException

IllegalArgumentException - if the writer is null

getStackTrace

public static String getStackTrace(Throwable throwable)

Get the stack trace of the supplied exception.

Parameters:

throwable - the exception for which the stack trace is to be returned

Returns:

the stack trace, or null if the supplied exception is null

normalize

public static String normalize(String text)

Removes leading and trailing whitespace from the supplied text, and reduces other consecutive whitespace characters to a single space. Whitespace includes line-feeds.

Parameters:

text - the text to be normalized

Returns:

the normalized text

getHexString

public static String getHexString(byte[] bytes)

Get the hexadecimal string representation of the supplied byte array.

Parameters:

bytes - the byte array

Returns:

the hex string representation of the byte array; never null

fromHexString

public static byte[] fromHexString(String hexadecimal)

isBlank

public static boolean isBlank(String str)

Returns true if the given string is null or represents the empty string

Parameters:

str - the string; may be null or empty

Returns:

true if the string is null or contains only whitespace