OpenTelemetry Java 1.49.0 · io.opentelemetry.api.internal.PercentEscaper

Note: This class is based on code from guava. It is comprised of code from three classes:

Escapes some set of Java characters using a UTF-8 based percent encoding scheme. The set of safe characters (those which remain unescaped) can be specified on construction.

This class is primarily used for creating URI escapers in UrlEscapers but can be used directly if required. While URI escapers impose specific semantics on which characters are considered 'safe', this class has a minimal set of restrictions.

When escaping a String, the following rules apply:

All specified safe characters remain unchanged.
If plusForSpace was specified, the space character " " is converted into a plus sign "+".
All other characters are converted into one or more bytes using UTF-8 encoding and each byte is then represented by the 3-character string "%XX", where "XX" is the two-digit, uppercase, hexadecimal representation of the byte value.

For performance reasons the only currently supported character encoding of this class is UTF-8.

Note

This escaper produces uppercase hexadecimal sequences.

This class is internal and is hence not for public use. Its APIs are unstable and can change at any time.

Field Summary

Modifier and Type	Field and Description
private static final int	DEST_PAD The amount of padding (chars) to use when growing the escape buffer.
private static final String	SAFE_CHARS
private static final boolean[]	safeOctets An array of flags where for any `char c` if `safeOctets[c]` is true then `c` should remain unmodified in the output.
private static final char[]	UPPER_HEX_DIGITS

Constructor Summary

Access	Constructor and Description
public	PercentEscaper()

Method Summary

Modifier and Type	Method and Description
private static int	Returns: the Unicode code point for the given index or the negated value of the trailing high surrogate character at the end of the sequence codePointAt(CharSequence the sequence of characters from which to decode the code point seq, int the index of the first character to decode index, int the index beyond the last valid character to decode end) Returns the Unicode code point of the character at the given index.
public static PercentEscaper	create() The default `PercentEscaper` which will not replace spaces with plus signs.
private static boolean[]	createSafeOctets(String safeChars) Creates a boolean array with entries corresponding to the character values specified in safeChars set to true.
public String	escape(String s) Escape the provided String, using percent-style URL Encoding.
private static char[]	escape(int cp) Escapes the given Unicode code point in UTF-8.
private static String	Returns: the escaped form of `string` escapeSlow(String the literal string to be escaped s, int the index to start escaping from index) Returns the escaped form of a given literal string, starting at the given index.
private static char[]	growBuffer(char[] dest, int index, int size) Helper method to grow the character buffer as needed, this only happens once in a while so it's ok if it's in a method call.
private static int	nextEscapeIndex(CharSequence csq, int index, int end)

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

DEST_PAD	back to summary
private static final int DEST_PAD The amount of padding (chars) to use when growing the escape buffer.

SAFE_CHARS	back to summary
private static final String SAFE_CHARS

safeOctets	back to summary
private static final boolean[] safeOctets An array of flags where for any `char c` if `safeOctets[c]` is true then `c` should remain unmodified in the output. If `c >= safeOctets.length` then it should be escaped.

UPPER_HEX_DIGITS	back to summary
private static final char[] UPPER_HEX_DIGITS

Constructor Detail

PercentEscaper	back to summary
public PercentEscaper()

Method Detail

codePointAt back to summary

codePointAt	back to summary
private static int codePointAt(CharSequence seq, int index, int end) Returns the Unicode code point of the character at the given index. Unlike `Character#codePointAt(CharSequence, int)` or `String#codePointAt(int)` this method will never fail silently when encountering an invalid surrogate pair. The behaviour of this method is as follows: If `index >= end`, `IndexOutOfBoundsException` is thrown. If the character at the specified index is not a surrogate, it is returned. If the first character was a high surrogate value, then an attempt is made to read the next character. If the end of the sequence was reached, the negated value of the trailing high surrogate is returned. If the next character was a valid low surrogate, the code point value of the high/low surrogate pair is returned. If the next character was not a low surrogate value, then `IllegalArgumentException` is thrown. If the first character was a low surrogate value, `IllegalArgumentException` is thrown. Parameters seq:CharSequence the sequence of characters from which to decode the code point index:int the index of the first character to decode end:int the index beyond the last valid character to decode Returns:int the Unicode code point for the given index or the negated value of the trailing high surrogate character at the end of the sequence

private static int codePointAt(CharSequence seq, int index, int end)

Returns the Unicode code point of the character at the given index.

Unlike Character#codePointAt(CharSequence, int) or String#codePointAt(int) this method will never fail silently when encountering an invalid surrogate pair.

The behaviour of this method is as follows:

If index >= end, IndexOutOfBoundsException is thrown.
If the character at the specified index is not a surrogate, it is returned.
If the first character was a high surrogate value, then an attempt is made to read the next character.
1. If the end of the sequence was reached, the negated value of the trailing high surrogate is returned.
2. If the next character was a valid low surrogate, the code point value of the high/low surrogate pair is returned.
3. If the next character was not a low surrogate value, then IllegalArgumentException is thrown.
If the first character was a low surrogate value, IllegalArgumentException is thrown.

Parameters

seq:CharSequence: the sequence of characters from which to decode the code point
index:int: the index of the first character to decode
end:int: the index beyond the last valid character to decode

Returns:int

the Unicode code point for the given index or the negated value of the trailing high surrogate character at the end of the sequence

create	back to summary
public static PercentEscaper create() The default `PercentEscaper` which will not replace spaces with plus signs.

createSafeOctets	back to summary
private static boolean[] createSafeOctets(String safeChars) Creates a boolean array with entries corresponding to the character values specified in safeChars set to true. The array is as small as is required to hold the given character information.

escape	back to summary
public String escape(String s) Escape the provided String, using percent-style URL Encoding.

escape	back to summary
private static char[] escape(int cp) Escapes the given Unicode code point in UTF-8. Annotations @CheckForNull @SuppressWarnings:UngroupedOverloads

escape

back to summary

private static char[] escape(int cp)

Escapes the given Unicode code point in UTF-8.

Annotations

@CheckForNull
@SuppressWarnings:UngroupedOverloads

escapeSlow back to summary

escapeSlow	back to summary
private static String escapeSlow(String s, int index) Returns the escaped form of a given literal string, starting at the given index. This method is called by the `escape(String)` method when it discovers that escaping is required. It is protected to allow subclasses to override the fastpath escaping function to inline their escaping test. This method is not reentrant and may only be invoked by the top level `escape(String)` method. Parameters s:String the literal string to be escaped index:int the index to start escaping from Returns:String the escaped form of `string` Exceptions NullPointerException: if `string` is null IllegalArgumentException: if invalid surrogate characters are encountered

private static String escapeSlow(String s, int index)

Returns the escaped form of a given literal string, starting at the given index. This method is called by the escape(String) method when it discovers that escaping is required. It is protected to allow subclasses to override the fastpath escaping function to inline their escaping test.

This method is not reentrant and may only be invoked by the top level escape(String) method.

Parameters

s:String: the literal string to be escaped
index:int: the index to start escaping from

Returns:String

the escaped form of string

Exceptions

NullPointerException:: if string is null
IllegalArgumentException:: if invalid surrogate characters are encountered

growBuffer	back to summary
private static char[] growBuffer(char[] dest, int index, int size) Helper method to grow the character buffer as needed, this only happens once in a while so it's ok if it's in a method call. If the index passed in is 0 then no copying will be done.

nextEscapeIndex	back to summary
private static int nextEscapeIndex(CharSequence csq, int index, int end)

public final Class PercentEscaper

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail