URLDecoder

public class URLDecoder extends Object

Utility class for HTML form decoding. This class contains static methods for decoding a String from the application/x-www-form-urlencoded MIME format.

The conversion process is the reverse of that used by the URLEncoder class. It is assumed that all characters in the encoded string are one of the following: "a" through "z", "A" through "Z", "0" through "9", and "-", "_", ".", and "*". The character "%" is allowed but is interpreted as the start of a special escaped sequence.

The following rules are applied in the conversion:

• The alphanumeric characters "a" through "z", "A" through "Z" and "0" through "9" remain the same.
• The special characters ".", "-", "*", and "_" remain the same.
• The plus sign "+" is converted into a space character "   " .
• A sequence of the form "%xy" will be treated as representing a byte where xy is the two-digit hexadecimal representation of the 8 bits. Then, all substrings that contain one or more of these byte sequences consecutively will be replaced by the character(s) whose encoding would result in those consecutive bytes. The encoding scheme used to decode these characters may be specified, or if unspecified, the default encoding of the platform will be used.

There are two possible ways in which this decoder could deal with illegal strings. It could either leave illegal characters alone or it could throw an IllegalArgumentException. Which approach the decoder takes is left to the implementation.

Public Constructor Summary

URLDecoder()

Public Method Summary

static String	decode(String s) This method is deprecated. The resulting string may vary depending on the platform's default encoding. Instead, use the decode(String,String) method to specify the encoding.
static String	decode(String s, String enc) Decodes a application/x-www-form-urlencoded string using a specific encoding scheme.

Inherited Method Summary

From class java.lang.Object

Object	clone() Creates and returns a copy of this Object.
boolean	equals(Object obj) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of Class that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait(long timeout, int nanos) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait(long timeout) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait() Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object.

Public Constructors

public URLDecoder ()

Public Methods

public static String decode (String s)

This method is deprecated.
The resulting string may vary depending on the platform's default encoding. Instead, use the decode(String,String) method to specify the encoding.

Decodes a x-www-form-urlencoded string. The platform's default encoding is used to determine what characters are represented by any consecutive sequences of the form "%xy".

Parameters

s	the String to decode

Returns

• the newly decoded String

public static String decode (String s, String enc)

Decodes a application/x-www-form-urlencoded string using a specific encoding scheme. The supplied encoding is used to determine what characters are represented by any consecutive sequences of the form "%xy".

Note: The World Wide Web Consortium Recommendation states that UTF-8 should be used. Not doing so may introduce incompatibilities.

Parameters

s	the String to decode
enc	The name of a supported character encoding.

Returns

• the newly decoded String

Throws

UnsupportedEncodingException	If character encoding needs to be consulted, but named character encoding is not supported

See Also

• URLEncoder.encode(java.lang.String, java.lang.String)