Class ShutdownHandler

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

public class ShutdownHandler extends Handler.Wrapper

A Handler that initiates a Shutdown of the Jetty Server it belongs to.

Used to trigger shutdown of a Jetty Server instance

Server Setup Example:

 Server server = new Server(8080);
 String shutdownToken = "secret password";
 boolean exitJvm = false;
 ShutdownHandler shutdown = new ShutdownHandler(shutdownToken, exitJvm));
 shutdown.setHandler(someOtherHandler);
 server.setHandler(someOtherHandlers);
 server.start();
 
Client Triggering Example

 public static void attemptShutdown(int port, String shutdownToken) {
   try {
     String encodedToken = URLEncoder.encode(shutdownToken);
     URI uri = URI.create("http://localhost:%d/shutdown?token=%s".formatted(port, shutdownCookie));
     HttpClient httpClient = HttpClient.newBuilder().build();
     HttpRequest httpRequest = HttpRequest.newBuilder(shutdownURI)
         .POST(HttpRequest.BodyPublishers.noBody())
         .build();
     HttpResponse<String> httpResponse = httpClient.send(httpRequest,
         HttpResponse.BodyHandlers.ofString(StandardCharsets.UTF_8));
     Assertions.assertEquals(200, httpResponse.statusCode());
     System.out.println(httpResponse.body());
     logger.info("Shutting down " + uri + ": " + httpResponse.body());
   } catch (IOException | InterruptedException e) {
     logger.debug("Shutdown Handler not available");
     // Okay - the server is not running
     throw new RuntimeException(e);
   }
 }
 
  • Constructor Details

    • ShutdownHandler

      public ShutdownHandler(String shutdownToken)
      Creates a Handler that lets the server be shut down remotely (but only from localhost).
      Parameters:
      shutdownToken - a secret password to avoid unauthorized shutdown attempts
    • ShutdownHandler

      public ShutdownHandler(String shutdownToken, boolean exitJVM)
      Creates a Handler that lets the server be shut down remotely (but only from localhost).
      Parameters:
      shutdownToken - a secret password to avoid unauthorized shutdown attempts
      exitJVM - If true, when the shutdown is executed, the handler class System.exit()
    • ShutdownHandler

      public ShutdownHandler(Handler handler, String shutdownPath, String shutdownToken, boolean exitJVM)
      Creates a Handler that lets the server be shut down remotely (but only from localhost).
      Parameters:
      handler - the handler to wrap
      shutdownPath - the path to respond to shutdown requests against (default is "/shutdown")
      shutdownToken - a secret password to avoid unauthorized shutdown attempts
      exitJVM - If true, when the shutdown is executed, the handler class System.exit()
  • Method Details

    • 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.
    • setExitJvm

      public void setExitJvm(boolean exitJvm)
    • isExitJvm

      public boolean isExitJvm()