com.github.robtimus.obfuscation.support

Class ObfuscatorUtils

java.lang.Object

com.github.robtimus.obfuscation.support.ObfuscatorUtils

public final class ObfuscatorUtils
extends Object

Utility methods that can be used for implementing Obfuscators.

Author:

Rob Spoor

Method Summary

Modifier and Type	Method and Description
static void	append(char[] array, Appendable destination) Appends an array of characters to an Appendable.
static void	append(char[] array, int start, int end, Appendable destination) Appends a portion of an array of characters to an Appendable.
static void	append(char c, int count, Appendable destination) Appends a single character a number of times to an Appendable.
static void	append(int c, Appendable destination) Appends a single character to an Appendable.
static void	append(String str, Appendable destination) Appends a string to an Appendable.
static void	append(String str, int start, int end, Appendable destination) Appends a portion of a string to an Appendable.
static LimitAppendable	appendAtMost(Appendable appendable, long limit) Returns an Appendable that will discard text after a specific amount of text has been appended.
static void	checkIndex(char[] array, int index) Checks whether or not an index is valid for a character array.
static void	checkIndex(CharSequence s, int index) Checks whether or not an index is valid for a CharSequence.
static void	checkOffsetAndLength(char[] array, int offset, int length) Checks whether or not an offset and length are valid for a character array.
static void	checkOffsetAndLength(CharSequence sequence, int offset, int length) Checks whether or not an offset and length are valid for a CharSequence.
static void	checkStartAndEnd(char[] array, int start, int end) Checks whether or not a start and end index are valid for a character array.
static void	checkStartAndEnd(CharSequence sequence, int start, int end) Checks whether or not a start and end index are valid for a CharSequence.
static CharSequence	concat(CharSequence first, CharSequence second) Concatenates two CharSequences into one.
static void	copyAll(Reader input, Appendable destination) Copies the contents of a Reader to an Appendable.
static Reader	copyTo(Reader input, Appendable appendable) Returns a Reader that transparently appends all text read from another Reader to an Appendable.
static CountingReader	counting(Reader input) Returns a Reader that counts all text read from another Reader.
static long	discardAll(Reader input) Discards the contents of a Reader.
static void	getChars(CharSequence src, int srcBegin, int srcEnd, char[] dst, int dstBegin) Copies characters from a CharSequence into a destination character array.
static int	indexOf(CharSequence s, int ch, int fromIndex, int toIndex) Returns the index within a CharSequence range of the first occurrence of a specific character.
static int	lastIndexOf(CharSequence s, int ch, int fromIndex, int toIndex) Returns the index within a CharSequence of the last occurrence of a specific character.
static void	maskAll(Reader input, char maskChar, Appendable destination) Copies the contents of a Reader to an Appendable, masking each character.
static CharSequence	readAll(Reader input) Reads the contents of a Reader.
static Reader	readAtMost(Reader input, int limit) Returns a Reader that is able to read only a portion of text from another Reader.
static Reader	reader(CharSequence s) Returns a Reader for a CharSequence.
static Reader	reader(CharSequence s, int start, int end) Returns a Reader for a portion of a CharSequence.
static CharSequence	repeatChar(char c, int count) Creates an immutable CharSequence that repeats a single character.
static int	skipLeadingWhitespace(CharSequence s, int fromIndex, int toIndex) Skips leading whitespace in a range of a CharSequence.
static int	skipTrailingWhitespace(CharSequence s, int fromIndex, int toIndex) Skips trailing whitespace in a range of a CharSequence.
static CharSequence	wrapArray(char[] array) Creates a CharSequence that wraps a character array.
static Writer	writer(Appendable appendable) Returns an Appendable as a Writer.

Methods inherited from class java.lang.Object

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

Method Detail

indexOf

public static int indexOf(CharSequence s,
                          int ch,
                          int fromIndex,
                          int toIndex)

Returns the index within a CharSequence range of the first occurrence of a specific character. This method is like String.indexOf(int, int), but it works on any CharSequence, and it has an upper bound as well.

Parameters:

s - The CharSequence to search.

ch - The character to search for.

fromIndex - The start of the CharSequence range, inclusive.

toIndex - The end of the CharSequence range, exclusive.

Returns:

The index of the given character in the given CharSequence, or -1 if the character does not occur in the given CharSequence in the specified range.

Throws:

NullPointerException - If the given CharSequence is null.

lastIndexOf

public static int lastIndexOf(CharSequence s,
                              int ch,
                              int fromIndex,
                              int toIndex)

Returns the index within a CharSequence of the last occurrence of a specific character. This method is like String.lastIndexOf(int, int) using toIndex - 1 as second argument, but it works on any CharSequence, and it has a lower bound as well.

Parameters:

s - The CharSequence to search.

ch - The character to search for.

fromIndex - The start of the CharSequence range, inclusive.

toIndex - The end of the CharSequence range, exclusive.

Returns:

The index of the given character in the given CharSequence, or -1 if the character does not occur in the given CharSequence in the specified range.

Throws:

NullPointerException - If the given CharSequence is null.

Since:

1.5

skipLeadingWhitespace

public static int skipLeadingWhitespace(CharSequence s,
                                        int fromIndex,
                                        int toIndex)

Skips leading whitespace in a range of a CharSequence.

Parameters:

s - The CharSequence to skip leading whitespace in.

fromIndex - The start of the range to start skipping whitespace in, inclusive.

toIndex - The end of the range to start skipping whitespace in, exclusive.

Returns:

The index in the given CharSequence of the first non-whitespace character, or toIndex if the CharSequence contains only whitespace.

Throws:

NullPointerException - If the given CharSequence is null.

IndexOutOfBoundsException - If the given indexes are invalid for the given CharSequence.

skipTrailingWhitespace

public static int skipTrailingWhitespace(CharSequence s,
                                         int fromIndex,
                                         int toIndex)

Skips trailing whitespace in a range of a CharSequence.

Parameters:

s - The CharSequence to skip trailing whitespace in.

fromIndex - The start of the range to start skipping whitespace in, inclusive.

toIndex - The end of the range to start skipping whitespace in, exclusive.

Returns:

The index in the given CharSequence of the first non-whitespace character, or fromIndex if the CharSequence contains only whitespace.

Throws:

IndexOutOfBoundsException - If the given indexes are invalid for the given CharSequence.

getChars

public static void getChars(CharSequence src,
                            int srcBegin,
                            int srcEnd,
                            char[] dst,
                            int dstBegin)

Copies characters from a CharSequence into a destination character array. This method is a more generic version of String.getChars(int, int, char[], int), StringBuilder.getChars(int, int, char[], int) and StringBuffer.getChars(int, int, char[], int).

Parameters:

src - The CharSequence to copy characters from.

srcBegin - The index of the first character in the CharSequence to copy.

srcEnd - The index after the last character in the CharSequence to copy.

dst - The destination array.

dstBegin - The start offset in the destination array.

Throws:

NullPointerException - If the given CharSequence or character array is null.

IndexOutOfBoundsException - If any of the indexes is invalid.

checkIndex

public static void checkIndex(char[] array,
                              int index)

Checks whether or not an index is valid for a character array.

Parameters:

array - The array to check for.

index - The index to check.

Throws:

NullPointerException - If the given array is null.

IndexOutOfBoundsException - If the given index is negative or exceeds the given array's length.

checkOffsetAndLength

public static void checkOffsetAndLength(char[] array,
                                        int offset,
                                        int length)

Checks whether or not an offset and length are valid for a character array.

Parameters:

array - The array to check for.

offset - The offset to check, inclusive.

length - The length to check.

Throws:

NullPointerException - If the given array is null.

IndexOutOfBoundsException - If the given offset is negative, the given length is negative, or the given offset and length exceed the given array's length.

checkStartAndEnd

public static void checkStartAndEnd(char[] array,
                                    int start,
                                    int end)

Checks whether or not a start and end index are valid for a character array.

Parameters:

array - The array to check for.

start - The start index to check, inclusive.

end - The end index to check, exclusive.

Throws:

NullPointerException - If the given array is null.

IndexOutOfBoundsException - If the given start index is negative, the given end index is larger than the given array's length, or the given start index is larger than the given end index.

checkIndex

public static void checkIndex(CharSequence s,
                              int index)

Checks whether or not an index is valid for a CharSequence.

Parameters:

s - The CharSequence to check for.

index - The index to check.

Throws:

NullPointerException - If the given CharSequence is null.

IndexOutOfBoundsException - If the given index is negative or exceeds the given CharSequence's length.

checkOffsetAndLength

public static void checkOffsetAndLength(CharSequence sequence,
                                        int offset,
                                        int length)

Checks whether or not an offset and length are valid for a CharSequence.

Parameters:

sequence - The CharSequence to check for.

offset - The offset to check, inclusive.

length - The length to check.

Throws:

NullPointerException - If the given CharSequence is null.

IndexOutOfBoundsException - If the given offset is negative, the given length is negative, or the given offset and length exceed the given CharSequence's length.

checkStartAndEnd

public static void checkStartAndEnd(CharSequence sequence,
                                    int start,
                                    int end)

Checks whether or not a start and end index are valid for a CharSequence.

Parameters:

sequence - The CharSequence to check for.

start - The start index to check, inclusive.

end - The end index to check, exclusive.

Throws:

NullPointerException - If the given CharSequence is null.

IndexOutOfBoundsException - If the given start index is negative, the given end index is larger than the given CharSequence's length, or the given start index is larger than the given end index.

wrapArray

public static CharSequence wrapArray(char[] array)

Creates a CharSequence that wraps a character array.

Parameters:

array - The array to wrap.

Returns:

a CharSequence wrapper around the given array.

Throws:

NullPointerException - If the given array is null.

repeatChar

public static CharSequence repeatChar(char c,
                                      int count)

Creates an immutable CharSequence that repeats a single character.

Parameters:

c - The character to repeat.

count - The number of times to repeat the character.

Returns:

A CharSequence that repeats the given character the given number of times.

Throws:

IllegalArgumentException - If the given number of times is negative.

concat

public static CharSequence concat(CharSequence first,
                                  CharSequence second)

Concatenates two CharSequences into one.

Parameters:

first - The first CharSequence.

second - The second CharSequence.

Returns:

The concatenated CharSequence.

Throws:

NullPointerException - If either CharSequence is null.

Since:

1.2

reader

public static Reader reader(CharSequence s)

Returns a Reader for a CharSequence.

Parameters:

s - The CharSequence to return a Reader for.

Returns:

A Reader for the given CharSequence.

reader

public static Reader reader(CharSequence s,
                            int start,
                            int end)

Returns a Reader for a portion of a CharSequence.

Parameters:

s - The CharSequence to return a Reader for.

start - The start index of the portion, inclusive.

end - The end index of the portion, inclusive.

Returns:

A Reader for the given portion of the given CharSequence.

Throws:

IndexOutOfBoundsException - If the given start index is negative, the given end index is larger than the given CharSequence's length, or the given start index is larger than the given end index.

writer

public static Writer writer(Appendable appendable)

Returns an Appendable as a Writer. If the given Appendable is a Writer, it is returned unmodified. Otherwise, a wrapper is returned that will delegate all calls to the wrapped Appendable. This includes flush() if the wrapped Appendable implements Flushable, and close() if the wrapped Appendable implements Closeable or AutoCloseable.

Note that the behaviour of closing a Writer wrapper depends on the wrapped Appendable. If it does not support closing, or if it still allows text to be appended after closing, then the closed AppendableWriter allows text to be appended after closing. If it does not allow text to be appended after closing, then neither will the closed Writer wrapper.

Parameters:

appendable - The Appendable to return a Writer for.

Returns:

The given Appendable itself if it's already a Writer, otherwise a wrapper around the given Appendable.

Throws:

NullPointerException - If the given Appendable is null.

counting

public static CountingReader counting(Reader input)

Returns a Reader that counts all text read from another Reader.

Parameters:

input - The Reader to read from.

Returns:

A Reader that counts all text read from the given Reader.

Throws:

NullPointerException - If the given Reader is null.

Since:

1.4

copyTo

public static Reader copyTo(Reader input,
                            Appendable appendable)

Returns a Reader that transparently appends all text read from another Reader to an Appendable. If the returned Reader is closed, the given Reader will be closed as well. The Appendable will not be closed though.

Parameters:

input - The Reader to read from.

appendable - The Appendable to write to.

Returns:

A Reader that transparently appends all text read from the given Reader to the given Appendable.

Throws:

NullPointerException - If the given Reader or Appendable is null.

readAtMost

public static Reader readAtMost(Reader input,
                                int limit)

Returns a Reader that is able to read only a portion of text from another Reader.

Parameters:

input - The Reader to read from.

limit - The maximum number of characters to read from the given Reader.

Returns:

A Reader that is able to read at most limit characters from the given Reader.

Throws:

NullPointerException - If the given Reader is null.

IllegalArgumentException - If the given limit is negative.

Since:

1.2

appendAtMost

public static LimitAppendable appendAtMost(Appendable appendable,
                                           long limit)

Returns an Appendable that will discard text after a specific amount of text has been appended.

Parameters:

appendable - The Appendable to append to.

limit - The maximum number of characters to append to the given Appendable.

Returns:

An Appendable that will discard text after a specific amount of text has been appended.

Throws:

NullPointerException - If the given Appendable is null.

IllegalArgumentException - If the given limit is negative.

Since:

1.4

readAll

public static CharSequence readAll(Reader input)
                            throws IOException

Reads the contents of a Reader.

Parameters:

input - The Reader to read the contents of.

Returns:

A CharSequence with the contents of the given Reader.

Throws:

NullPointerException - If the given Reader is null.

IOException - If an I/O error occurs.

discardAll

public static long discardAll(Reader input)
                       throws IOException

Discards the contents of a Reader.

Parameters:

input - The Reader to discard the contents of.

Returns:

The number of discarded characters.

Throws:

NullPointerException - If the given Reader is null.

IOException - If an I/O error occurs.

copyAll

public static void copyAll(Reader input,
                           Appendable destination)
                    throws IOException

Copies the contents of a Reader to an Appendable.

Parameters:

input - The Reader to copy the contents of.

destination - The Appendable to copy the contents to.

Throws:

NullPointerException - If the given Reader or Appendable is null.

IOException - If an I/O error occurs.

maskAll

public static void maskAll(Reader input,
                           char maskChar,
                           Appendable destination)
                    throws IOException

Copies the contents of a Reader to an Appendable, masking each character.

Parameters:

input - The Reader to copy the contents of.

maskChar - The character to replace with.

destination - The Appendable to copy the contents to.

Throws:

NullPointerException - If the given Reader or Appendable is null.

IOException - If an I/O error occurs.

append

public static void append(int c,
                          Appendable destination)
                   throws IOException

Appends a single character to an Appendable. The character to be written is contained in the 16 low-order bits of the given integer value; the 16 high-order bits are ignored.

Parameters:

c - The character to append.

destination - The Appendable to append to.

Throws:

NullPointerException - If the given Appendable is null.

IOException - If an I/O error occurs.

append

public static void append(char c,
                          int count,
                          Appendable destination)
                   throws IOException

Appends a single character a number of times to an Appendable.

Parameters:

c - The character to append.

count - The number of times to append the character.

destination - The Appendable to append to.

Throws:

IllegalArgumentException - If the given number of times is negative.

NullPointerException - If the given Appendable is null.

IOException - If an I/O error occurs.

append

public static void append(char[] array,
                          Appendable destination)
                   throws IOException

Appends an array of characters to an Appendable.

Parameters:

array - The array to append.

destination - The Appendable to append to.

Throws:

NullPointerException - If the given array or Appendable is null.

IOException - If an I/O error occurs.

append

public static void append(char[] array,
                          int start,
                          int end,
                          Appendable destination)
                   throws IOException

Appends a portion of an array of characters to an Appendable.

Parameters:

array - The array to append a portion of.

destination - The Appendable to append to.

start - The start index of the portion to append, inclusive.

end - The end index of the portion to append, exclusive.

Throws:

NullPointerException - If the given array or Appendable is null.

IndexOutOfBoundsException - If the given start index is negative, the given end index is larger than the given array's length, or the given start index is larger than the given end index.

IOException - If an I/O error occurs.

append

public static void append(String str,
                          Appendable destination)
                   throws IOException

Appends a string to an Appendable.

Parameters:

str - The string to append.

destination - The Appendable to append to.

Throws:

NullPointerException - If the given string or Appendable is null.

IOException - If an I/O error occurs.

append

public static void append(String str,
                          int start,
                          int end,
                          Appendable destination)
                   throws IOException

Appends a portion of a string to an Appendable.

Parameters:

str - The string to append a portion of.

destination - The Appendable to append to.

start - The start index of the portion to append, inclusive.

end - The end index of the portion to append, exclusive.

Throws:

NullPointerException - If the given string or Appendable is null.

IndexOutOfBoundsException - If the given start index is negative, the given end index is larger than the given string's length, or the given start index is larger than the given end index.

IOException - If an I/O error occurs.