Class InMemoryCachingHttpClientBuilder

java.lang.Object
net.shibboleth.utilities.java.support.httpclient.HttpClientBuilder
net.shibboleth.utilities.java.support.httpclient.InMemoryCachingHttpClientBuilder

public class InMemoryCachingHttpClientBuilder
extends HttpClientBuilder
An HttpClient builder that supports RFC 2616 caching.

This client will cache information retrieved from the remote server in memory. The backing store does not perform any resource management (e.g., removing content that has nominally expired) so, special care must be taken to tune the maxCacheEntries and maxCacheEntrySize appropriately so that the system's memory is not fully consumed.

When using the single-arg constructor variant to wrap an existing instance of CachingHttpClientBuilder, there are several caveats of which to be aware:

  • Several important non-caching-specific caveats are enumerated in this class's superclass HttpClientBuilder.
  • Instances of the following which are set as the default instance on the Apache builder will be unconditionally overwritten by this builder when HttpClientBuilder.buildClient() is called:
    • CacheConfig

    This is due to the unfortunate fact that the Apache builder does not currently provide accessor methods to obtain the default instances currently set on the builder. Therefore, if you need to set any default cache config parameters which are not exposed by this builder, then you must use the Apache builder directly and may not use this builder.

  • Field Details

    • maxCacheEntries

      private int maxCacheEntries
      The maximum number of cached responses. Default: 50
    • maxCacheEntrySize

      private long maxCacheEntrySize
      The maximum response body size, in bytes, that will be eligible for caching. Default: 1048576 (1 megabyte)
  • Constructor Details

    • InMemoryCachingHttpClientBuilder

      public InMemoryCachingHttpClientBuilder()
      Constructor.
    • InMemoryCachingHttpClientBuilder

      public InMemoryCachingHttpClientBuilder​(@Nonnull org.apache.http.impl.client.cache.CachingHttpClientBuilder builder)
      Constructor.
      Parameters:
      builder - builder of clients used to fetch data from remote servers
  • Method Details

    • getMaxCacheEntries

      public int getMaxCacheEntries()
      Gets the maximum number of cached responses.
      Returns:
      maximum number of cached responses
    • setMaxCacheEntries

      public void setMaxCacheEntries​(int maxEntries)
      Sets the maximum number of cached responses.
      Parameters:
      maxEntries - maximum number of cached responses, must be greater than zero
    • getMaxCacheEntrySize

      public long getMaxCacheEntrySize()
      Gets the maximum response body size, in bytes, that will be eligible for caching.
      Returns:
      maximum response body size that will be eligible for caching
    • setMaxCacheEntrySize

      public void setMaxCacheEntrySize​(long size)
      Sets the maximum response body size, in bytes, that will be eligible for caching.
      Parameters:
      size - maximum response body size that will be eligible for caching, must be greater than zero
    • decorateApacheBuilder

      protected void decorateApacheBuilder() throws Exception
      Decorate the Apache builder as determined by this builder's parameters. Subclasses will likely add additional decoration.
      Overrides:
      decorateApacheBuilder in class HttpClientBuilder
      Throws:
      Exception - if there is a problem decorating the Apache builder