com.google.appengine.api.appidentity

## Interface AppIdentityService

-     public interface AppIdentityService

  The `AppIdentityService` allows you to sign arbitrary byte array using per app private key maintained by App Egnine, and also you can retrieve a list of public certificates which can be used to verify the signature.

  App Engine is responsible for maintaining per application private key. AppEngine will keep rotating private keys periodically. App Engine never gives these private keys to outside.

  Since private keys are rotated periodically, `getPublicCertificatesForApp()` could return a list of public certificates, it's caller's responsibility to try these certificates one by one when doing signature verification.

- - ### Nested Class Summary

    Nested Classes
    Modifier and Type | Interface and Description
    --- | ---
    `static class` | `AppIdentityService.GetAccessTokenResult` `GetAccessTokenResult` is returned by getAccessToken.
    `static class` | `AppIdentityService.ParsedAppId` Class holding the results of parsing a full application id into its constituent parts.
    `static class` | `AppIdentityService.SigningResult` `SigningResult` is returned by signForApp, which contains signing key name and signature.

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `AppIdentityService.GetAccessTokenResult` | `getAccessToken(java.lang.Iterable<java.lang.String> scopes)` OAuth2 access token to act on behalf of the application.
    `AppIdentityService.GetAccessTokenResult` | `getAccessTokenUncached(java.lang.Iterable<java.lang.String> scopes)` OAuth2 access token to act on behalf of the application, uncached.
    `java.util.Collection<PublicCertificate>` | `getPublicCertificatesForApp()` Retrieves a list of public certificates.
    `java.lang.String` | `getServiceAccountName()` Gets service account name of the app.
    `AppIdentityService.ParsedAppId` | `parseFullAppId(java.lang.String fullAppId)` Parse a full app id into partition, domain name and display app_id.
    `AppIdentityService.SigningResult` | `signForApp(byte[] signBlob)` Requests to sign arbitrary byte array using per app private key.

- - ### Method Detail

    - #### signForApp

          AppIdentityService.SigningResult signForApp(byte[] signBlob)

      Requests to sign arbitrary byte array using per app private key.
      Parameters:
        `signBlob` - string blob.
      Returns:
        a SigningResult object which contains signing key name and signature.
      Throws:
        `AppIdentityServiceFailureException`

    - #### getPublicCertificatesForApp

          java.util.Collection<PublicCertificate> getPublicCertificatesForApp()

      Retrieves a list of public certificates.
      Returns:
        a list of public certificates.
      Throws:
        `AppIdentityServiceFailureException`

    - #### getServiceAccountName

          java.lang.String getServiceAccountName()

      Gets service account name of the app.
      Returns:
        service account name of the app.

    - #### getAccessTokenUncached

          AppIdentityService.GetAccessTokenResult getAccessTokenUncached(java.lang.Iterable<java.lang.String> scopes)

      OAuth2 access token to act on behalf of the application, uncached. Most developers should use getAccessToken instead.
      Parameters:
        `scopes` - iterable of scopes to request.
      Returns:
        a GetAccessTokenResult object with the access token and expiration time.
      Throws:
        `AppIdentityServiceFailureException`

    - #### getAccessToken

          AppIdentityService.GetAccessTokenResult getAccessToken(java.lang.Iterable<java.lang.String> scopes)

      OAuth2 access token to act on behalf of the application. Generates and caches an OAuth2 access token for the service account for the appengine application. Each application has an associated Google account. This function returns OAuth2 access token corresponding to the running app. Access tokens are safe to cache and reuse until their expiry time as returned. This method will do that using memcache.
      Parameters:
        `scopes` - iterable of scopes to request.
      Returns:
        a GetAccessTokenResult object with the access token and expiration time.
      Throws:
        `AppIdentityServiceFailureException`

    - #### parseFullAppId

          AppIdentityService.ParsedAppId parseFullAppId(java.lang.String fullAppId)

      Parse a full app id into partition, domain name and display app_id.
      Parameters:
        `fullAppId` - The full partitioned app id.
      Returns:
        An `AppIdentityService.ParsedAppId` instance with the parsing results.