Class Credentials (1.30.0) 

public abstract class Credentials implements Serializable

Represents an abstract authorized identity instance.

Inheritance

java.lang.Object > Credentials

Implements

Serializable

Static Fields

GOOGLE_DEFAULT_UNIVERSE

public static final String GOOGLE_DEFAULT_UNIVERSE
Field Value
Type Description
String

Constructors

Credentials()

public Credentials()

Methods

blockingGetToCallback(URI uri, RequestMetadataCallback callback)

protected final void blockingGetToCallback(URI uri, RequestMetadataCallback callback)

Call #getRequestMetadata(URI) and pass the result or error to the callback.

Parameters
Name Description
uri URI

URI of the entry point for the request.
callback RequestMetadataCallback

Callback handler to execute when the metadata completes.

getAuthenticationType()

public abstract String getAuthenticationType()

A constant string name describing the authentication technology.

E.g. “OAuth2”, “SSL”. For use by the transport layer to determine whether it supports the type of authentication in the case where Credentials#hasRequestMetadataOnly is false. Also serves as a debugging helper.

Returns
Type Description
String

The type of authentication used.

getMetricsCredentialType()

public CredentialTypeForMetrics getMetricsCredentialType()

Gets the credential type used for internal metrics header.

The default is CredentialTypeForMetrics.DO_NOT_SEND. For a credential that is established to track for metrics, this default should be overridden.

Returns
Type Description
CredentialTypeForMetrics

a enum value for credential type

getRequestMetadata()

public Map<String,List<String>> getRequestMetadata()

Get the current request metadata, refreshing tokens if required.

This should be called by the transport layer on each request, and the data should be populated in headers or other context. The operation can block and fail to complete and may do things such as refreshing access tokens.

The convention for handling binary data is for the key in the returned map to end with "-bin" and for the corresponding values to be base64 encoded.

Returns
Type Description
Map<String,List<String>>

The request metadata used for populating headers or other context.
Exceptions
Type Description
IOException

if there was an error getting up-to-date access.

getRequestMetadata(URI uri)

public abstract Map<String,List<String>> getRequestMetadata(URI uri)

Get the current request metadata in a blocking manner, refreshing tokens if required.

This should be called by the transport layer on each request, and the data should be populated in headers or other context. The operation can block and fail to complete and may do things such as refreshing access tokens.

The convention for handling binary data is for the key in the returned map to end with "-bin" and for the corresponding values to be base64 encoded.

Parameter
Name Description
uri URI

URI of the entry point for the request.
Returns
Type Description
Map<String,List<String>>

The request metadata used for populating headers or other context.
Exceptions
Type Description
IOException

if there was an error getting up-to-date access. The exception should implement Retryable and isRetryable() will return true if the operation may be retried.

getRequestMetadata(URI uri, Executor executor, RequestMetadataCallback callback)

public void getRequestMetadata(URI uri, Executor executor, RequestMetadataCallback callback)

Get the current request metadata without blocking.

This should be called by the transport layer on each request, and the data should be populated in headers or other context. The implementation can either call the callback inline or asynchronously. Either way it should never block in this method. The executor is provided for tasks that may block.

The default implementation will just call #getRequestMetadata(URI) then the callback from the given executor.

The convention for handling binary data is for the key in the returned map to end with "-bin" and for the corresponding values to be base64 encoded.

Parameters
Name Description
uri URI

URI of the entry point for the request.
executor Executor

Executor to perform the request.
callback RequestMetadataCallback

Callback to execute when the request is finished.

getUniverseDomain()

public String getUniverseDomain()

Gets the universe domain for the credential in a blocking manner, refreshing tokens if required.

Returns
Type Description
String

a universe domain value in the format some-domain.xyz. By default, returns the Google universe domain googleapis.com.
Exceptions
Type Description
IOException

extending classes might have to do remote calls to determine the universe domain. The exception must implement Retryable and isRetryable() will return true if the operation may be retried.

hasRequestMetadata()

public abstract boolean hasRequestMetadata()

Whether the credentials have metadata entries that should be added to each request.

This should be called by the transport layer to see if Credentials#getRequestMetadata should be used for each request.

Returns
Type Description
boolean

Whether or not the transport layer should call Credentials#getRequestMetadata

hasRequestMetadataOnly()

public abstract boolean hasRequestMetadataOnly()

Indicates whether or not the Auth mechanism works purely by including request metadata.

This is meant for the transport layer. If this is true a transport does not need to take actions other than including the request metadata. If this is false, a transport must specifically know about the authentication technology to support it, and should fail to accept the credentials otherwise.

Returns
Type Description
boolean

Whether or not the Auth mechanism works purely by including request metadata.

refresh()

public abstract void refresh()

Refresh the authorization data, discarding any cached state.

For use by the transport to allow retry after getting an error indicating there may be invalid tokens or other cached state.

Exceptions
Type Description
IOException

if there was an error getting up-to-date access.