Class OAuth2Credentials

    • Field Detail

      • DEFAULT_EXPIRATION_MARGIN

        static final java.time.Duration DEFAULT_EXPIRATION_MARGIN
      • DEFAULT_REFRESH_MARGIN

        static final java.time.Duration DEFAULT_REFRESH_MARGIN
      • EMPTY_EXTRA_HEADERS

        private static final com.google.common.collect.ImmutableMap<java.lang.String,​java.util.List<java.lang.String>> EMPTY_EXTRA_HEADERS
      • expirationMargin

        private final java.time.Duration expirationMargin
      • refreshMargin

        private final java.time.Duration refreshMargin
      • lock

        final java.lang.Object lock
      • clock

        transient com.google.api.client.util.Clock clock
    • Constructor Detail

      • OAuth2Credentials

        protected OAuth2Credentials()
        Default constructor.
      • OAuth2Credentials

        protected OAuth2Credentials​(AccessToken accessToken)
        Constructor with explicit access token.
        Parameters:
        accessToken - initial or temporary access token
      • OAuth2Credentials

        protected OAuth2Credentials​(AccessToken accessToken,
                                    java.time.Duration refreshMargin,
                                    java.time.Duration expirationMargin)
    • Method Detail

      • create

        public static OAuth2Credentials create​(AccessToken accessToken)
        Returns the credentials instance from the given access token.
        Parameters:
        accessToken - the access token
        Returns:
        the credentials instance
      • getAuthenticationType

        public java.lang.String getAuthenticationType()
        Description copied from class: Credentials
        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.

        Specified by:
        getAuthenticationType in class Credentials
        Returns:
        The type of authentication used.
      • hasRequestMetadataOnly

        public boolean hasRequestMetadataOnly()
        Description copied from class: Credentials
        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.

        Specified by:
        hasRequestMetadataOnly in class Credentials
        Returns:
        Whether or not the Auth mechanism works purely by including request metadata.
      • getAccessToken

        public final AccessToken getAccessToken()
        Returns the cached access token.

        If not set, you should call refresh() to fetch and cache an access token.

        Returns:
        The cached access token.
      • getRefreshMargin

        java.time.Duration getRefreshMargin()
        Returns the credentials' refresh margin.
      • getExpirationMargin

        java.time.Duration getExpirationMargin()
        Returns the credentials' expiration margin.
      • getRequestMetadata

        public void getRequestMetadata​(java.net.URI uri,
                                       java.util.concurrent.Executor executor,
                                       RequestMetadataCallback callback)
        Description copied from class: Credentials
        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 Credentials.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.

        Overrides:
        getRequestMetadata in class Credentials
        Parameters:
        uri - URI of the entry point for the request.
        executor - Executor to perform the request.
        callback - Callback to execute when the request is finished.
      • getRequestMetadata

        public java.util.Map<java.lang.String,​java.util.List<java.lang.String>> getRequestMetadata​(java.net.URI uri)
                                                                                                  throws java.io.IOException
        Provide the request metadata by ensuring there is a current access token and providing it as an authorization bearer token.
        Specified by:
        getRequestMetadata in class Credentials
        Parameters:
        uri - URI of the entry point for the request.
        Returns:
        The request metadata used for populating headers or other context.
        Throws:
        java.io.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.
      • refresh

        public void refresh()
                     throws java.io.IOException
        Request a new token regardless of the current token state. If the current token is not expired, it will still be returned during the refresh.
        Specified by:
        refresh in class Credentials
        Throws:
        java.io.IOException - if there was an error getting up-to-date access.
      • refreshIfExpired

        public void refreshIfExpired()
                              throws java.io.IOException
        Refresh these credentials only if they have expired or are expiring imminently.
        Throws:
        java.io.IOException - during token refresh.
      • asyncFetch

        private com.google.common.util.concurrent.ListenableFuture<OAuth2Credentials.OAuthValue> asyncFetch​(java.util.concurrent.Executor executor)
        Attempts to get a fresh token.

        If a fresh token is already available, it will be immediately returned. Otherwise a refresh will be scheduled using the passed in executor. While a token is being freshed, a stale value will be returned.

      • getOrCreateRefreshTask

        private OAuth2Credentials.AsyncRefreshResult getOrCreateRefreshTask()
        Atomically creates a single flight refresh token task.

        Only a single refresh task can be scheduled at a time. If there is an existing task, it will be returned for subsequent invocations. However if a new task is created, it is the responsibility of the caller to execute it. The task will clear the single flight slow upon completion.

      • finishRefreshAsync

        private void finishRefreshAsync​(com.google.common.util.concurrent.ListenableFuture<OAuth2Credentials.OAuthValue> finishedTask)
        Async callback for committing the result from a token refresh.

        The result will be stored, listeners are invoked and the single flight slot is cleared.

      • unwrapDirectFuture

        private static <T> T unwrapDirectFuture​(com.google.common.util.concurrent.ListenableFuture<T> future)
                                         throws java.io.IOException
        Unwraps the value from the future.

        Under most circumstances, the underlying future will already be resolved by the DirectExecutor. In those cases, the error stacktraces will be rooted in the caller's call tree. However, in some cases when async and sync usage is mixed, it's possible that a blocking call will await an async future. In those cases, the stacktrace will be orphaned and be rooted in a thread of whatever executor the async call used. This doesn't affect correctness and is extremely unlikely.

        Throws:
        java.io.IOException
      • refreshAccessToken

        public AccessToken refreshAccessToken()
                                       throws java.io.IOException
        Method to refresh the access token according to the specific type of credentials.

        Throws IllegalStateException if not overridden since direct use of OAuth2Credentials is only for temporary or non-refreshing access tokens.

        Returns:
        never
        Throws:
        java.lang.IllegalStateException - always. OAuth2Credentials does not support refreshing the access token. An instance with a new access token or a derived type that supports refreshing should be used instead.
        java.io.IOException
      • getAdditionalHeaders

        protected java.util.Map<java.lang.String,​java.util.List<java.lang.String>> getAdditionalHeaders()
        Provide additional headers to return as request metadata.
        Returns:
        additional headers
      • addChangeListener

        public final void addChangeListener​(OAuth2Credentials.CredentialsChangedListener listener)
        Adds a listener that is notified when the Credentials data changes.

        This is called when token content changes, such as when the access token is refreshed. This is typically used by code caching the access token.

        Parameters:
        listener - the listener to be added
      • hashCode

        public int hashCode()
        Overrides:
        hashCode in class java.lang.Object
      • getRequestMetadataInternal

        @Nullable
        protected java.util.Map<java.lang.String,​java.util.List<java.lang.String>> getRequestMetadataInternal()
      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object
      • equals

        public boolean equals​(java.lang.Object obj)
        Overrides:
        equals in class java.lang.Object
      • readObject

        private void readObject​(java.io.ObjectInputStream input)
                         throws java.io.IOException,
                                java.lang.ClassNotFoundException
        Throws:
        java.io.IOException
        java.lang.ClassNotFoundException
      • newInstance

        protected static <T> T newInstance​(java.lang.String className)
                                    throws java.io.IOException,
                                           java.lang.ClassNotFoundException
        Throws:
        java.io.IOException
        java.lang.ClassNotFoundException
      • getFromServiceLoader

        protected static <T> T getFromServiceLoader​(java.lang.Class<? extends T> clazz,
                                                    T defaultInstance)