java.net
Class URLEncoder

java.lang.Object
  |
  +--java.net.URLEncoder
public class URLEncoder
extends Object

Utility class for HTML form encoding. This class contains static methods for converting a String to the application/x-www-form-urlencoded MIME format. For more information about HTML form encoding, consult the HTML specification.

When encoding a String, the following rules apply:

  • The alphanumeric characters "a" through "z", "A" through "Z" and "0" through "9" remain the same.
  • The special characters ".", "-", "*", and "_" remain the same.
  • The space character " " is converted into a plus sign "+".
  • All other characters are unsafe and are first converted into one or more bytes using some encoding scheme. Then each byte is represented by the 3-character string "%xy", where xy is the two-digit hexadecimal representation of the byte. The recommended encoding scheme to use is UTF-8. However, for compatibility reasons, if an encoding is not specified, then the default encoding of the platform is used.

For example using UTF-8 as the encoding scheme the string "The string ü@foo-bar" would get converted to "The+string+%C3%BC%40foo-bar" because in UTF-8 the character ü is encoded as two bytes C3 (hex) and BC (hex), and the character @ is encoded as one byte 40 (hex).

Since:
JDK1.0

 

Method Summary

static String encode(String s)
    Deprecated. The resulting string may vary depending on the platform's default encoding. Instead, use the encode(String,String) method to specify the encoding.
static String encode(String s, String enc)
    Translates a string into application/x-www-form-urlencoded format using a specific encoding scheme.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

 

Method Detail

 

encode

public static String encode(String s)
Deprecated. The resulting string may vary depending on the platform's default encoding. Instead, use the encode(String,String) method to specify the encoding.

Translates a string into x-www-form-urlencoded format. This method uses the platform's default encoding as the encoding scheme to obtain the bytes for unsafe characters.

Parameters:
s - String to be translated.
Returns:
the translated String.

 

encode

public static String encode(String s,
                            String enc)
                     throws UnsupportedEncodingException
Translates a string into application/x-www-form-urlencoded format using a specific encoding scheme. This method uses the supplied encoding scheme to obtain the bytes for unsafe characters.

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

Parameters:
s - String to be translated.
enc - The name of a supported encoding.
Returns:
the translated String.
Throws:
UnsupportedEncodingException - If the named encoding is not supported
Since:
1.4
See Also:
URLDecoder.decode(java.lang.String, java.lang.String)