Added in API level 1

URLEncoder

public class URLEncoder
extends Object

java.lang.Object
   ↳ java.net.URLEncoder


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).

Summary

Public methods

static String encode(String s, String enc)

Translates a string into application/x-www-form-urlencoded format using a specific encoding scheme.

static String encode(String s)

This method was deprecated in API level 15. 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, Charset charset)

Translates a string into application/x-www-form-urlencoded format using a specific Charset.

Inherited methods

Public methods

encode

Added in API level 1
public static String encode (String s, 
                String enc)

Translates a string into application/x-www-form-urlencoded format using a specific encoding scheme.

This method behaves the same as encode(String s, Charset charset) except that it will look up the charset using the given encoding name.

Parameters
s String: String to be translated.

enc String: The name of a supported character encoding.

Returns
String the translated String.

Throws
UnsupportedEncodingException If the named encoding is not supported

encode

Added in API level 1
Deprecated in API level 15
public static String encode (String s)

This method was deprecated in API level 15.
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: String to be translated.

Returns
String the translated String.

encode

Added in API level 33
public static String encode (String s, 
                Charset charset)

Translates a string into application/x-www-form-urlencoded format using a specific Charset. This method uses the supplied charset 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 incompatibilities.

Parameters
s String: String to be translated.

charset Charset: the given charset

Returns
String the translated String.

Throws
NullPointerException if s or charset is null.