Class HTTPMetadataResolver

All Implemented Interfaces:
Iterable<EntityDescriptor>, Component, DestructableComponent, IdentifiableComponent, IdentifiedComponent, InitializableComponent, Resolver<EntityDescriptor,​CriteriaSet>, IterableMetadataSource, BatchMetadataResolver, MetadataResolver, RefreshableMetadataResolver
Direct Known Subclasses:
FileBackedHTTPMetadataResolver

public class HTTPMetadataResolver
extends AbstractReloadingMetadataResolver
A metadata provider that pulls metadata using an HTTP GET. Metadata is cached until one of these criteria is met:
  • The smallest cacheDuration within the metadata is exceeded
  • The earliest validUntil time within the metadata is exceeded
  • The maximum cache duration is exceeded
Metadata is filtered prior to determining the cache expiration data. This allows a filter to remove XMLObjects that may effect the cache duration but for which the user of this provider does not care about. It is the responsibility of the caller to re-initialize, via AbstractInitializableComponent.initialize(), if any properties of this provider are changed.
  • Field Details

    • log

      @Nonnull private final org.slf4j.Logger log
      Class logger.
    • httpClient

      private org.apache.http.client.HttpClient httpClient
      HTTP Client used to pull the metadata.
    • metadataURI

      private URI metadataURI
      URL to the Metadata.
    • cachedMetadataETag

      private String cachedMetadataETag
      The ETag provided when the currently cached metadata was fetched.
    • cachedMetadataLastModified

      private String cachedMetadataLastModified
      The Last-Modified information provided when the currently cached metadata was fetched.
    • httpClientSecurityParameters

      @Nullable private HttpClientSecurityParameters httpClientSecurityParameters
      Optional HttpClient security parameters.
  • Constructor Details

    • HTTPMetadataResolver

      public HTTPMetadataResolver​(org.apache.http.client.HttpClient client, String metadataURL) throws ResolverException
      Constructor.
      Parameters:
      client - HTTP client used to pull in remote metadata
      metadataURL - URL to the remove remote metadata
      Throws:
      ResolverException - thrown if the HTTP client is null or the metadata URL provided is invalid
    • HTTPMetadataResolver

      public HTTPMetadataResolver​(Timer backgroundTaskTimer, org.apache.http.client.HttpClient client, String metadataURL) throws ResolverException
      Constructor.
      Parameters:
      backgroundTaskTimer - timer used to schedule background metadata refresh tasks
      client - HTTP client used to pull in remote metadata
      metadataURL - URL to the remove remote metadata
      Throws:
      ResolverException - thrown if the HTTP client is null or the metadata URL provided is invalid
  • Method Details

    • getMetadataURI

      public String getMetadataURI()
      Gets the URL to fetch the metadata.
      Returns:
      the URL to fetch the metadata
    • getHttpClientSecurityParameters

      @Nullable protected HttpClientSecurityParameters getHttpClientSecurityParameters()
      Get the instance of HttpClientSecurityParameters which provides various parameters to influence the security behavior of the HttpClient instance.
      Returns:
      the parameters instance, or null
    • setHttpClientSecurityParameters

      public void setHttpClientSecurityParameters​(@Nullable HttpClientSecurityParameters params)
      Set an instance of HttpClientSecurityParameters which provides various parameters to influence the security behavior of the HttpClient instance.

      For all TLS-related parameters, must be used in conjunction with an HttpClient instance which is configured with either a:

      For convenience methods for building a TLSSocketFactory, see HttpClientSupport.

      If the appropriate TLS socket factory is not configured and a trust engine is specified, then this will result in no TLS trust evaluation being performed and a ResolverException will ultimately be thrown.

      Parameters:
      params - the security parameters
    • doDestroy

      protected void doDestroy()
      Overrides:
      doDestroy in class AbstractReloadingMetadataResolver
    • getMetadataIdentifier

      protected String getMetadataIdentifier()
      Gets an identifier which may be used to distinguish this metadata in logging statements.
      Specified by:
      getMetadataIdentifier in class AbstractReloadingMetadataResolver
      Returns:
      identifier which may be used to distinguish this metadata in logging statements
    • fetchMetadata

      protected byte[] fetchMetadata() throws ResolverException
      Gets the metadata document from the remote server.
      Specified by:
      fetchMetadata in class AbstractReloadingMetadataResolver
      Returns:
      the metadata from remote server, or null if the metadata document has not changed since the last retrieval
      Throws:
      ResolverException - thrown if there is a problem retrieving the metadata from the remote server
    • buildHttpGet

      protected org.apache.http.client.methods.HttpGet buildHttpGet()
      Builds the HttpGet instance used to fetch the metadata. The returned method advertises support for GZIP and deflate compression, enables conditional GETs if the cached metadata came with either an ETag or Last-Modified information, and sets up basic authentication if such is configured.
      Returns:
      the constructed HttpGet instance
    • buildHttpClientContext

      protected org.apache.http.client.protocol.HttpClientContext buildHttpClientContext​(@Nonnull org.apache.http.client.methods.HttpUriRequest request)
      Build the HttpClientContext instance which will be used to invoke the HttpClient request.
      Parameters:
      request - the current HTTP request
      Returns:
      a new instance of HttpClientContext
    • processConditionalRetrievalHeaders

      protected void processConditionalRetrievalHeaders​(org.apache.http.HttpResponse response)
      Records the ETag and Last-Modified headers, from the response, if they are present.
      Parameters:
      response - GetMethod containing a valid HTTP response
    • getMetadataBytesFromResponse

      protected byte[] getMetadataBytesFromResponse​(org.apache.http.HttpResponse response) throws ResolverException
      Extracts the raw metadata bytes from the response taking in to account possible deflate and GZip compression.
      Parameters:
      response - GetMethod containing a valid HTTP response
      Returns:
      the raw metadata bytes
      Throws:
      ResolverException - thrown if there is a problem getting the raw metadata bytes from the response