Package org.eclipse.jetty.server

Interface HttpInput.Interceptor

All Known Implementing Classes:

GzipHttpInputInterceptor

Enclosing class:

HttpInput

public static interface HttpInput.Interceptor

HttpInput.Content interceptor that can be registered using HttpInput.setInterceptor(Interceptor) or HttpInput.addInterceptor(Interceptor). When HttpInput.Content instances are generated, they are passed to the registered interceptor (if any) that is then responsible for providing the actual content that is consumed by HttpInput.read(byte[], int, int) and its sibling methods.

A minimal implementation could be as simple as:

 public HttpInput.Content readFrom(HttpInput.Content content)
 {
     LOGGER.debug("read content: {}", asString(content));
     return content;
 }
 

which would not do anything with the content besides logging it. A more involved implementation could look like the following:

 public HttpInput.Content readFrom(HttpInput.Content content)
 {
     if (content.hasContent())
         this.processedContent = processContent(content.getByteBuffer());
     if (content.isEof())
         disposeResources();
     return content.isSpecial() ? content : this.processedContent;
 }
 

Implementors of this interface must keep the following in mind:

• Calling HttpInput.Content.getByteBuffer() when HttpInput.Content.isSpecial() returns true throws IllegalStateException.
• A HttpInput.Content can both be non-special and have HttpInput.Content.isEof() return true.
• HttpInput.Content extends Callback to manage the lifecycle of the contained byte buffer. The code calling readFrom(Content) is responsible for managing the lifecycle of both the passed and the returned content instances, once Buffer.hasRemaining() returns false HttpInput will make sure Callback.succeeded() is called, or Callback.failed(Throwable) if an error occurs.
• After readFrom(Content) is called for the first time, subsequent readFrom(Content) calls will occur only after the contained byte buffer is empty (see above) or at any time if the returned content was special.
• Once readFrom(Content) returned a special content, subsequent calls to readFrom(Content) must always return the same special content.
• Implementations implementing both this interface and Destroyable will have their Destroyable.destroy() method called when HttpInput.recycle() is called.

See Also:

• GzipHttpInputInterceptor

Method Summary

Modifier and Type	Method	Description
HttpInput.Content	readFrom(HttpInput.Content content)

Method Details

readFrom

HttpInput.Content readFrom(HttpInput.Content content)

Parameters:

content - The content to be intercepted. The content will be modified with any data the interceptor consumes. There is no requirement that all the data is consumed by the interceptor but at least one byte must be consumed unless the returned content is the passed content instance.

Returns:

The intercepted content or null if interception is completed for that content.