Stay organized with collections
Save and categorize content based on your preferences.
URLDecoder
open class URLDecoder
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 java.lang.IllegalArgumentException. Which approach the decoder takes is left to the implementation.
Summary
| Public methods |
| open static String! |
Decodes a x-www-form-urlencoded string.
|
| open static String! |
Decodes an application/x-www-form-urlencoded string using a specific encoding scheme.
|
| open static String! |
Decodes an application/x-www-form-urlencoded string using a specific Charset.
|
Public constructors
Public methods
decode
open static fun decode(s: String!): String!
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 |
String!: the String to decode |
| Return |
String! |
the newly decoded String |
decode
open static fun decode(
s: String!,
enc: String!
): String!
Decodes an application/x-www-form-urlencoded string using a specific encoding scheme.
This method behaves the same as decode(String s, Charset charset) except that it will look up the charset using the given encoding name.
| Return |
String! |
the newly decoded String |
| Exceptions |
java.io.UnsupportedEncodingException |
If character encoding needs to be consulted, but named character encoding is not supported |
decode
open static fun decode(
s: String!,
charset: Charset!
): String!
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.
| Parameters |
s |
String!: the String to decode |
charset |
Charset!: the given charset |
| Return |
String! |
the newly decoded String |
| Exceptions |
java.lang.NullPointerException |
if s or charset is null |
java.lang.IllegalArgumentException |
if the implementation encounters illegal characters |
Content and code samples on this page are subject to the licenses described in the Content License. Java and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.
Last updated 2025-02-10 UTC.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-02-10 UTC."],[],[],null,["# URLDecoder\n\nAdded in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)\n\nURLDecoder\n==========\n\n```\nopen class URLDecoder\n```\n\n|---|--------------------------|\n| [kotlin.Any](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-any/index.html) ||\n| ↳ | [java.net.URLDecoder](#) |\n\nUtility class for HTML form decoding. This class contains static methods for decoding a String from the `application/x-www-form-urlencoded` MIME format.\n\nThe 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.\n\nThe following rules are applied in the conversion:\n\n- The alphanumeric characters \"`a`\" through \"`z`\", \"`A`\" through \"`Z`\" and \"`0`\" through \"`9`\" remain the same.\n- The special characters \"`.`\", \"`-`\", \"`*`\", and \"`_`\" remain the same.\n- The plus sign \"`+`\" is converted into a space character \" \" .\n- 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.\n\nThere 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 [java.lang.IllegalArgumentException](../lang/IllegalArgumentException.html#). Which approach the decoder takes is left to the implementation.\n\nSummary\n-------\n\n| Public constructors ||\n|----------------------------------------|---|\n| [URLDecoder](#URLDecoder())`()` \u003cbr /\u003e |\n\n| Public methods ||\n|-----------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|\n| open static [String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html)! | [decode](#decode(kotlin.String))`(`s:` `[String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html)!`)` Decodes a `x-www-form-urlencoded` string. |\n| open static [String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html)! | [decode](#decode(kotlin.String,%20kotlin.String))`(`s:` `[String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html)!`, `enc:` `[String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html)!`)` Decodes an `application/x-www-form-urlencoded` string using a specific encoding scheme. |\n| open static [String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html)! | [decode](#decode(kotlin.String,%20java.nio.charset.Charset))`(`s:` `[String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html)!`, `charset:` `[Charset](../nio/charset/Charset.html#)!`)` Decodes an `application/x-www-form-urlencoded` string using a specific [Charset](../nio/charset/Charset.html#). |\n\nPublic constructors\n-------------------\n\n### URLDecoder\n\nAdded in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) \n\n```\nURLDecoder()\n```\n\nPublic methods\n--------------\n\n### decode\n\nAdded in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) \nDeprecated in [API level 15](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) \n\n```\nopen static fun decode(s: String!): String!\n```\n\n**Deprecated:** *The resulting string may vary depending on the platform's default encoding. Instead, use the decode(String,String) method to specify the encoding.*\n\nDecodes 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`*\".\n\n| Parameters ||\n|-----|-----------------------------------------------------------------------------------------------------------|\n| `s` | [String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html)!: the `String` to decode |\n\n| Return ||\n|-----------------------------------------------------------------------------------|----------------------------|\n| [String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html)! | the newly decoded `String` |\n\n### decode\n\nAdded in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) \n\n```\nopen static fun decode(\n s: String!, \n enc: String!\n): String!\n```\n\nDecodes an `application/x-www-form-urlencoded` string using a specific encoding scheme.\n\nThis method behaves the same as [decode(String s, Charset charset)](../lang/String.html#) except that it will [look up the charset](../nio/charset/Charset.html#forName(kotlin.String)) using the given encoding name.\n\n| Parameters ||\n|-------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------|\n| `s` | [String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html)!: the `String` to decode |\n| `enc` | [String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html)!: The name of a supported [character encoding](../lang/package-summary.html#charenc). |\n\n| Return ||\n|-----------------------------------------------------------------------------------|----------------------------|\n| [String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html)! | the newly decoded `String` |\n\n| Exceptions ||\n|----------------------------------------|--------------------------------------------------------------------------------------------|\n| `java.io.UnsupportedEncodingException` | If character encoding needs to be consulted, but named character encoding is not supported |\n\n**See Also**\n\n- [java.net.URLEncoder#encode(java.lang.String, java.lang.String)](/reference/kotlin/java/net/URLEncoder#encode(kotlin.String,%20kotlin.String)) \n\n### decode\n\nAdded in [API level 33](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) \n\n```\nopen static fun decode(\n s: String!, \n charset: Charset!\n): String!\n```\n\nDecodes an `application/x-www-form-urlencoded` string using a specific [Charset](../nio/charset/Charset.html#). The supplied charset is used to determine what characters are represented by any consecutive sequences of the form \"*`%xy`*\".\n\n***Note:** The [World Wide Web Consortium Recommendation](http://www.w3.org/TR/html40/appendix/notes.html#non-ascii-chars) states that UTF-8 should be used. Not doing so may introduce incompatibilities.*\n\n| Parameters ||\n|-----------|-----------------------------------------------------------------------------------------------------------|\n| `s` | [String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html)!: the `String` to decode |\n| `charset` | [Charset](../nio/charset/Charset.html#)!: the given charset |\n\n| Return ||\n|-----------------------------------------------------------------------------------|----------------------------|\n| [String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html)! | the newly decoded `String` |\n\n| Exceptions ||\n|--------------------------------------|-----------------------------------------------------|\n| `java.lang.NullPointerException` | if `s` or `charset` is `null` |\n| `java.lang.IllegalArgumentException` | if the implementation encounters illegal characters |\n\n**See Also**\n\n- [java.net.URLEncoder#encode(java.lang.String, java.nio.charset.Charset)](/reference/kotlin/java/net/URLEncoder#encode(kotlin.String,%20java.nio.charset.Charset))"]]
