Class GracefulHandler

java.lang.Object
org.eclipse.jetty.util.component.AbstractLifeCycle
org.eclipse.jetty.util.component.ContainerLifeCycle
org.eclipse.jetty.server.Handler.Abstract
org.eclipse.jetty.server.Handler.AbstractContainer
org.eclipse.jetty.server.Handler.Wrapper
org.eclipse.jetty.server.handler.GracefulHandler
All Implemented Interfaces:
Handler, Handler.Container, Handler.Singleton, Request.Handler, Container, Destroyable, Dumpable, Dumpable.DumpableContainer, Graceful, LifeCycle, Invocable
public class GracefulHandler extends Handler.Wrapper implements Graceful
Handler to track active requests and allow them to gracefully complete.

  • Constructor Details

    • GracefulHandler

      public GracefulHandler()

    • GracefulHandler

      public GracefulHandler(Handler handler)

  • Method Details

    • getCurrentRequestCount

      @ManagedAttribute("number of requests being currently handled") public long getCurrentRequestCount()

    • getCurrentStreamWrapperCount

      @ManagedAttribute("number of stream wrappers currently pending") public long getCurrentStreamWrapperCount()

    • isShutdown

      public boolean isShutdown()
      Flag indicating that Graceful shutdown has been initiated.
      Specified by:
      isShutdown in interface Graceful
      Returns:
      whether the graceful shutdown has been initiated
      See Also:

    • handle

      public boolean handle(Request request, Response response, Callback callback) throws Exception
      Description copied from interface: Request.Handler

      Invoked to handle the passed HTTP request and response.

      The request is accepted by returning true, then handling must be concluded by completing the passed callback. The handling may be asynchronous, i.e. this method may return true and complete the given callback later, possibly from a different thread. If this method returns false, then the callback must not be invoked and any mutation on the response reversed.

      Exceptions thrown by this method may be subsequently handled by an error Request.Handler, if present, otherwise a default HTTP 500 error is generated and the callback completed while writing the error response.

      The simplest implementation is:

      public boolean handle(Request request, Response response, Callback callback)
{
    callback.succeeded();
    return true;
}

      A HelloWorld implementation is:

      public boolean handle(Request request, Response response, Callback callback)
{
    response.write(true, ByteBuffer.wrap("Hello World\n".getBytes(StandardCharsets.UTF_8)), callback);
    return true;
}
      Specified by:
      handle in interface Request.Handler
      Overrides:
      handle in class Handler.Wrapper
      Parameters:
      request - the HTTP request to handle
      response - the HTTP response to handle
      callback - the callback to complete when the handling is complete
      Returns:
      True if and only if the request will be handled, a response generated and the callback eventually called. This may occur within the scope of the call to this method, or asynchronously some time later. If false is returned, then this method must not generate a response, nor complete the callback.
      Throws:
      Exception - if there is a failure during the handling. Catchers cannot assume that the callback will be called and thus should attempt to complete the request as if a false had been returned.
      See Also:

    • doStart

      protected void doStart() throws Exception
      Description copied from class: ContainerLifeCycle
      Starts the managed lifecycle beans in the order they were added.
      Overrides:
      doStart in class Handler.Abstract
      Throws:
      Exception - If there was a problem starting. Will cause a transition to FAILED state

    • shutdown

      public CompletableFuture<Void> shutdown()
      Description copied from interface: Graceful
      Shutdown the component. When this method returns, the component should not accept any new load.
      Specified by:
      shutdown in interface Graceful
      Returns:
      A future that is completed once all load on the component is completed