Package Summary  Overview Summary

class:URLDecoder [NONE]


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:URLDecoder() [NONE]

  • URLDecoder

    @Deprecated(since="16", forRemoval=true) public URLDecoder()
    Deprecated, for removal: This API element is subject to removal in a future version.
    Do not call.

method:decode(java.lang.String) [NONE]

  • decode

    @Deprecatedpublic static  String decode​(String s)
    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
  • method:decode(java.lang.String,java.lang.String) [NONE]

    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 - 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
    Since:
    1.4
    See Also:
    URLEncoder.encode(java.lang.String, java.lang.String)

    method:decode(java.lang.String,java.nio.charset.Charset) [NONE]

    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 - the String to decode
    charset - the given charset
    Returns:
    the newly decoded String
    Throws:
    NullPointerException - if s or charset is null
    IllegalArgumentException - if the implementation encounters illegal characters
    Since:
    10
    See Also:
    URLEncoder.encode(java.lang.String, java.nio.charset.Charset)