Embedded Jetty not serving empty files

Question

Setup: I have set up embedded jetty (v9.1) to serve static files with the setDirectoriesListed(true) and the code I am using is below:

    // Create a basic Jetty server object that will listen on port 8080.  Note that if you set this to port 0
    // then a randomly available port will be assigned that you can either look in the logs for the port,
    // or programmatically obtain it for use in test cases.
    Server server = new Server(9090);

    // Create the ResourceHandler. It is the object that will actually handle the request for a given file. It is
    // a Jetty Handler object so it is suitable for chaining with other handlers as you will see in other examples.
    ResourceHandler resource_handler = new ResourceHandler();
    // Configure the ResourceHandler. Setting the resource base indicates where the files should be served out of.
    // In this example it is the current directory but it can be configured to anything that the jvm has access to.
    resource_handler.setDirectoriesListed(true);
    resource_handler.setWelcomeFiles(new String[]{ "index.html" });
    resource_handler.setResourceBase(".");

    // Add the ResourceHandler to the server.
    HandlerList handlers = new HandlerList();
    handlers.setHandlers(new Handler[] { resource_handler, new DefaultHandler() });
    server.setHandler(handlers);

    // Start things up! By using the server.join() the server thread will join with the current thread.
    // See "http://docs.oracle.com/javase/1.5.0/docs/api/java/lang/Thread.html#join()" for more details.
    server.start();
    server.join();

This code is originally from here.

When I navigate to the address http://localhost:9090/, I see the files listed in the directory and I am able to click and open individual text files.

Problem: For some inexplicable reason, only when I click on a file of 0 bytes (aka it's an empty file, but still shown in the browser), the connection tries to load but eventually times out (30 seconds) and I get a response in safari saying the "server unexpectedly dropped the connection." In addition, when I make a HttpURLConnection to the 0 byte file, I get a content length returned of -1; This of course is only for empty files.

Expected Behavior as seen in standalone Jetty: When I use standalone jetty and serve the same files, I am able to "open" the empty file which just returns a blank page in a web browser. When using the HttpURLConnection, I get a content length of 0.

While this seems like a "pointless" task, one server is programmatically syncing with the embedded jetty server (so I want those empty files to sync). I imagine it has something to do with the resource handler seeing 0 bytes as it serves the static content, but I'm not too sure how to get the same behavior of the standalone jetty server as right now, it errors when trying to pull the empty files.

Thanks!

Joakim Erdfelt Joakim Erdfelt · Accepted Answer · 2015-01-20T18:59:42

Your code works, as-is, at least on Jetty 9.2.7.v20140116

Full example I used:

package jetty;

import java.io.File;

import org.eclipse.jetty.server.Handler;
import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.server.handler.DefaultHandler;
import org.eclipse.jetty.server.handler.HandlerList;
import org.eclipse.jetty.server.handler.ResourceHandler;

public class SimpleResources
{
    public static void main(String[] args)
    {
        Server server = new Server(9090);

        String resourceBase = System.getProperty("resourceBase", ".");

        System.err.printf("Resource Base is: %s%n", new File(resourceBase).getAbsolutePath());

        ResourceHandler resource_handler = new ResourceHandler();
        resource_handler.setDirectoriesListed(true);
        resource_handler.setWelcomeFiles(new String[] { "index.html" });
        resource_handler.setResourceBase(resourceBase);

        HandlerList handlers = new HandlerList();
        handlers.setHandlers(new Handler[] { resource_handler, new DefaultHandler() });
        server.setHandler(handlers);

        try
        {
            server.start();
            server.join();
        }
        catch (Throwable t)
        {
            t.printStackTrace(System.err);
        }
    }
}

I ran it pointing the -DresourceBase system property to a directory that has the following ...

$ ls -la
total 8
drwxrwxr-x. 2 joakim joakim 4096 Jan 20 11:53 .
drwxrwxr-x. 3 joakim joakim 4096 Jan 20 11:53 ..
-rw-rw-r--. 1 joakim joakim    0 Jan 20 11:53 foo.txt

And once running the console shows ...

2015-01-20 11:55:07.788:INFO::main: Logging initialized @68ms
Resource Base is: /home/joakim/code/Jetty/empties
2015-01-20 11:55:07.837:INFO:oejs.Server:main: jetty-9.2.7.v20150116
2015-01-20 11:55:07.860:INFO:oejs.ServerConnector:main: Started ServerConnector@5461eda{HTTP/1.1}{0.0.0.0:9090}
2015-01-20 11:55:07.861:INFO:oejs.Server:main: Started @144ms

With a test request like such ...

$ curl --dump-header - http://localhost:9090/foo.txt
HTTP/1.1 200 OK
Date: Tue, 20 Jan 2015 18:55:39 GMT
Content-Type: text/plain
Content-Length: 0
Server: Jetty(9.2.7.v20150116)

Update:

Works as-is with no modifications on the following versions of jetty as well (didn't do an exhaustive test of versions, just a few older ones as well)

9.2.6.v20141205 - Identical Results
9.2.4.v20141103 - Identical Results
9.2.1.v20140609 - Identical Results
9.1.5.v20140505 - No Date in response headers, rest is the same (yes, it also sends Content-Length: 0)

Embedded Jetty not serving empty files

1 Answers