Class DebugHandler

All Implemented Interfaces:
EventListener, Connection.Listener, Handler, Handler.Container, Handler.Singleton, Request.Handler, Container, Destroyable, Dumpable, Dumpable.DumpableContainer, LifeCycle, Invocable

public class DebugHandler extends Handler.Wrapper implements Connection.Listener
Debug Handler.

A lightweight debug handler that can be used in production code. Details of the request and response are written to an output stream and the current thread name is updated with information that will link to the details in that output.

Note that due to async processing, the logging of request processing may appear out of order.

  • Constructor Details

    • DebugHandler

      public DebugHandler()
    • DebugHandler

      public DebugHandler(Handler handler)
  • Method Details

    • isShowHeaders

      public boolean isShowHeaders()
    • setShowHeaders

      public void setShowHeaders(boolean showHeaders)
    • 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:
    • log

      protected void log(String format, Object... arg)
    • findRequestName

      protected String findRequestName(Request request)
    • 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:
      AbstractLifeCycle.StopException - If thrown, the lifecycle will immediately be stopped.
      Exception - If there was a problem starting. Will cause a transition to FAILED state
    • doStop

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

      public OutputStream getOutputStream()
      Get the out.
      Returns:
      the out
    • setOutputStream

      public void setOutputStream(OutputStream out)
      Set the out to set.
      Parameters:
      out - the out to set
    • onOpened

      public void onOpened(Connection connection)
      Specified by:
      onOpened in interface Connection.Listener
    • onClosed

      public void onClosed(Connection connection)
      Specified by:
      onClosed in interface Connection.Listener