Class Handler.Wrapper

All Implemented Interfaces:
Handler, Handler.Container, Handler.Singleton, Request.Handler, Container, Destroyable, Dumpable, Dumpable.DumpableContainer, LifeCycle, Invocable
Direct Known Subclasses:
ConditionalHandler, ConnectHandler, ContextHandler, CrossOriginHandler, DebugHandler, DelayedHandler, EagerFormHandler, EventsHandler, GracefulHandler, GzipHandler, IdleTimeoutHandler, ResourceHandler, RewriteHandler, SecuredRedirectHandler, SecurityHandler, Server, ServletHandler, ShutdownHandler, SizeLimitHandler, TryPathsHandler, WebSocketUpgradeHandler, WebSocketUpgradeHandler
Enclosing interface:
Handler

public static class Handler.Wrapper extends Handler.AbstractContainer implements Handler.Singleton

An implementation of Handler.Singleton, which is a Handler.Container that wraps one single other Handler.

A Handler.Wrapper may be dynamic, that is allow Handlers to be set after it has been started.

If this Handler.Wrapper is dynamic, then its invocation type is by default Invocable.InvocationType.BLOCKING.

  • Constructor Details

    • Wrapper

      public Wrapper()

      Creates a wrapper with no wrapped Handler.

    • Wrapper

      public Wrapper(boolean dynamic)

      Creates a wrapper with no wrapped Handler with the given dynamic parameter.

      Parameters:
      dynamic - whether this container is dynamic
    • Wrapper

      public Wrapper(Handler handler)

      Creates a non-dynamic wrapper of the given Handler.

      Parameters:
      handler - the Handler to wrap
    • Wrapper

      public Wrapper(boolean dynamic, Handler handler)

      Creates a wrapper with the given dynamic parameter wrapping the given Handler.

      Parameters:
      dynamic - whether this container is dynamic
      handler - the Handler to wrap
  • Method Details

    • getHandler

      public Handler getHandler()
      Specified by:
      getHandler in interface Handler.Singleton
      Returns:
      the child Handler
    • setHandler

      public void setHandler(Handler handler)
      Specified by:
      setHandler in interface Handler.Singleton
      Parameters:
      handler - The Handler to set as a child
    • 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
      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.
    • getInvocationType

      public Invocable.InvocationType getInvocationType()
      Specified by:
      getInvocationType in interface Invocable
      Specified by:
      getInvocationType in interface Request.Handler
      Overrides:
      getInvocationType in class Handler.AbstractContainer
      Returns:
      The InvocationType of this object