Class URLDecoder
- java.lang.Object
-
- java.net.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.
- Since:
- 1.2
Constructor Summary
Constructor | Description |
---|---|
URLDecoder() |
Method Summary
Modifier and Type | Method | Description |
---|---|---|
static String | decode(String s) | Deprecated. The resulting string may vary depending on the platform's default encoding. |
static String | decode(String s,
String enc) | Decodes an |
static String | decode(String s,
Charset charset) | Decodes an |
Methods declared in class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Constructor Detail
URLDecoder
public URLDecoder()
Method Detail
decode
@Deprecated public static String decode(String s)
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
- theString
to decode - Returns:
- the newly decoded
String
decode
public static String decode(String s, String enc) throws UnsupportedEncodingException
Decodes an application/x-www-form-urlencoded
string using a specific encoding scheme.
This method behaves the same as decode(java.lang.String,java.nio.charset.Charset) except that it will look up the charset using the given encoding name.
- Implementation Note:
- This implementation will throw an
IllegalArgumentException
when illegal strings are encountered. - Parameters:
-
s
- theString
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 - Since:
- 1.4
- See Also:
URLEncoder.encode(java.lang.String, java.lang.String)
decode
public static String decode(String s, Charset charset)
Decodes an application/x-www-form-urlencoded
string using a specific Charset. The supplied charset 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.
- Implementation Note:
- This implementation will throw an
IllegalArgumentException
when illegal strings are encountered. - Parameters:
-
s
- theString
to decode -
charset
- the given charset - Returns:
- the newly decoded
String
- Throws:
-
NullPointerException
- ifs
orcharset
isnull
-
IllegalArgumentException
- if the implementation encounters illegal characters - Since:
- 10
- See Also:
URLEncoder.encode(java.lang.String, java.nio.charset.Charset)