org.yaml.snakeyaml.external.com.google.gdata.util.common.base

Class PercentEscaper

java.lang.Object

org.yaml.snakeyaml.external.com.google.gdata.util.common.base.UnicodeEscaper

org.yaml.snakeyaml.external.com.google.gdata.util.common.base.PercentEscaper

All Implemented Interfaces:

Escaper

public class PercentEscaper
extends UnicodeEscaper

A UnicodeEscaper that escapes some set of Java characters using the URI percent encoding scheme. The set of safe characters (those which remain unescaped) can be specified on construction.

For details on escaping URIs for use in web pages, see section 2.4 of RFC 3986.

In most cases this class should not need to be used directly. If you have no special requirements for escaping your URIs, you should use either

When encoding a String, the following rules apply:

• The alphanumeric characters "a" through "z", "A" through "Z" and "0" through "9" remain the same.
• Any additionally specified safe characters remain the same.
• 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 "%XY", where "XY" is the two-digit, uppercase, hexadecimal representation of the byte value.

RFC 2396 specifies the set of unreserved characters as "-", "_", ".", "!", "~", "*", "'", "(" and ")". It goes on to state:

Unreserved characters can be escaped without changing the semantics of the URI, but this should not be done unless the URI is being used in a context that does not allow the unescaped character to appear.

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

Note: This escaper produces uppercase hexidecimal sequences. From RFC 3986:
"URI producers and normalizers should use uppercase hexadecimal digits for all percent-encodings."

Field Summary

Fields

Modifier and Type	Field and Description
static String	SAFECHARS_URLENCODER
static String	SAFEPATHCHARS_URLENCODER A string of characters that do not need to be encoded when used in URI path segments, as specified in RFC 3986.
static String	SAFEQUERYSTRINGCHARS_URLENCODER A string of characters that do not need to be encoded when used in URI query strings, as specified in RFC 3986.

Constructor Summary

Constructors

Constructor and Description
PercentEscaper(String safeChars, boolean plusForSpace) Constructs a URI escaper with the specified safe characters and optional handling of the space character.

Method Summary

Modifier and Type	Method and Description
protected char[]	escape(int cp) Escapes the given Unicode code point in UTF-8.
String	escape(String s) Returns the escaped form of a given literal string.
protected int	nextEscapeIndex(CharSequence csq, int index, int end)

Methods inherited from class org.yaml.snakeyaml.external.com.google.gdata.util.common.base.UnicodeEscaper

codePointAt, escape, escapeSlow

Methods inherited from class java.lang.Object

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

Field Detail

SAFECHARS_URLENCODER

public static final String SAFECHARS_URLENCODER

See Also:

Constant Field Values

SAFEPATHCHARS_URLENCODER

public static final String SAFEPATHCHARS_URLENCODER

A string of characters that do not need to be encoded when used in URI path segments, as specified in RFC 3986. Note that some of these characters do need to be escaped when used in other parts of the URI.

See Also:

Constant Field Values

SAFEQUERYSTRINGCHARS_URLENCODER

public static final String SAFEQUERYSTRINGCHARS_URLENCODER

A string of characters that do not need to be encoded when used in URI query strings, as specified in RFC 3986. Note that some of these characters do need to be escaped when used in other parts of the URI.

See Also:

Constant Field Values

Constructor Detail

PercentEscaper

public PercentEscaper(String safeChars,
                      boolean plusForSpace)

Constructs a URI escaper with the specified safe characters and optional handling of the space character.

Parameters:

safeChars - a non null string specifying additional safe characters for this escaper (the ranges 0..9, a..z and A..Z are always safe and should not be specified here)

plusForSpace - true if ASCII space should be escaped to + rather than %20

Throws:

IllegalArgumentException - if any of the parameters were invalid

Method Detail

nextEscapeIndex

protected int nextEscapeIndex(CharSequence csq,
                              int index,
                              int end)

Overrides:

nextEscapeIndex in class UnicodeEscaper

escape

public String escape(String s)

Description copied from interface: Escaper

Returns the escaped form of a given literal string.

Note that this method may treat input characters differently depending on the specific escaper implementation.

Specified by:

escape in interface Escaper

Overrides:

escape in class UnicodeEscaper

Parameters:

s - the literal string to be escaped

Returns:

the escaped form of string

escape

protected char[] escape(int cp)

Escapes the given Unicode code point in UTF-8.

Specified by:

escape in class UnicodeEscaper

Parameters:

cp - the Unicode code point to escape if necessary

Returns:

the replacement characters, or null if no escaping was needed