# Class BasicAuthenticator

java.lang.Object
com.sun.net.httpserver.Authenticator
com.sun.net.httpserver.BasicAuthenticator

public abstract class BasicAuthenticator extends Authenticator
BasicAuthenticator provides an implementation of HTTP Basic authentication. It is an abstract class and must be extended to provide an implementation of `checkCredentials(String,String)` which is called to verify each incoming request.

Since:
  1.6

- ## Nested Class Summary

  ### Nested classes/interfaces declared in class com.sun.net.httpserver.Authenticator

  `Authenticator.Failure, Authenticator.Result, Authenticator.Retry, Authenticator.Success`

- ## Field Summary

  Fields
  Modifier and Type
  Field
  Description
  `protected final String`
  `realm`
  The HTTP Basic authentication realm.

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `BasicAuthenticator(String realm)`
  Creates a `BasicAuthenticator` for the given HTTP realm.
  `BasicAuthenticator(String realm, Charset charset)`
  Creates a `BasicAuthenticator` for the given HTTP realm and using the given `Charset` to decode the Basic authentication credentials (username and password).

- ## Method Summary

  Modifier and Type
  Method
  Description
  `Authenticator.Result`
  `authenticate(HttpExchange t)`
  Called to authenticate each incoming request.
  `abstract boolean`
  `checkCredentials(String username, String password)`
  Called for each incoming request to verify the given name and password in the context of this authenticator's realm.
  `String`
  `getRealm()`
  Returns the realm this `BasicAuthenticator` was created with.

  ### Methods declared in class java.lang.Object

  `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- ## Field Details

  - ### realm

    protected final String realm
    The HTTP Basic authentication realm.

- ## Constructor Details

  - ### BasicAuthenticator

    public BasicAuthenticator(String realm)
    Creates a `BasicAuthenticator` for the given HTTP realm. The Basic authentication credentials (username and password) are decoded using the platform's `default character set`.
    API Note:
      The value of the `realm` parameter will be embedded in a quoted string.
    Parameters:
      `realm` - the HTTP Basic authentication realm
    Throws:
      `NullPointerException` - if realm is `null`
      `IllegalArgumentException` - if realm is an empty string or is not correctly quoted, as specified in RFC 7230 section-3.2. Note, any `\` character used for quoting must itself be quoted in source code.

  - ### BasicAuthenticator

    public BasicAuthenticator(String realm, Charset charset)
    Creates a `BasicAuthenticator` for the given HTTP realm and using the given `Charset` to decode the Basic authentication credentials (username and password).
    API Note:
      `UTF-8` is the recommended charset because its usage is communicated to the client, and therefore more likely to be used also by the client.

      The value of the `realm` parameter will be embedded in a quoted string.

    Parameters:
      `realm` - the HTTP Basic authentication realm
      `charset` - the `Charset` to decode incoming credentials from the client
    Throws:
      `NullPointerException` - if realm or charset are `null`
      `IllegalArgumentException` - if realm is an empty string or is not correctly quoted, as specified in RFC 7230 section-3.2. Note, any `\` character used for quoting must itself be quoted in source code.
    Since:
      14

- ## Method Details

  - ### getRealm

    public String getRealm()
    Returns the realm this `BasicAuthenticator` was created with.
    Returns:
      the authenticator's realm string

  - ### authenticate

    public Authenticator.Result authenticate(HttpExchange t)
    Description copied from class: `Authenticator`
    Called to authenticate each incoming request. The implementation must return a `Authenticator.Failure`, `Authenticator.Success` or `Authenticator.Retry` object as appropriate:
    - `Failure` means the authentication has completed, but has failed due to invalid credentials.
    - `Success` means that the authentication has succeeded, and a `Principal` object representing the user can be retrieved by calling `Authenticator.Success.getPrincipal()`.
    - `Retry` means that another HTTP exchange is required. Any response headers needing to be sent back to the client are set in the given `HttpExchange`. The response code to be returned must be provided in the `Retry` object. `Retry` may occur multiple times.
    Specified by:
      `authenticate` in class `Authenticator`
    Parameters:
      `t` - the `HttpExchange` upon which authenticate is called
    Returns:
      the result

  - ### checkCredentials

    public abstract boolean checkCredentials(String username, String password)
    Called for each incoming request to verify the given name and password in the context of this authenticator's realm. Any caching of credentials must be done by the implementation of this method.
    Parameters:
      `username` - the username from the request
      `password` - the password from the request
    Returns:
      `true` if the credentials are valid, `false` otherwise