Added in API level 1

URLEncoder

open class URLEncoder
kotlin.Any
   ↳ 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
open static String!

Translates a string into x-www-form-urlencoded format.
open static String!
encode(s: String!, enc: String!)

Translates a string into application/x-www-form-urlencoded format using a specific encoding scheme.
open static String!
encode(s: String!, charset: Charset!)

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

Public methods

encode

Added in API level 1
Deprecated in API level 15
open static fun encode(s: String!): String!

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!: String to be translated.
Return
String! the translated String.

encode

Added in API level 1
open static fun encode(
    s: String!, 
    enc: String!
): String!

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.
Return
String! the translated String.
Exceptions
java.io.UnsupportedEncodingException If the named encoding is not supported

encode

Added in API level 33
open static fun encode(
    s: String!, 
    charset: Charset!
): String!

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
Return
String! the translated String.
Exceptions
java.lang.NullPointerException if s or charset is null.