Cannot retrieve logs

[chamilad]

I'm trying to retrieve the logs of a container which starts, executes a program which outputs to stdout, and stops. Following is the code snippet I'm using. However, I'm getting a null as the result of logHandler.getOutput(), and a NPE at line 17. However, when queried through the Docker API manually, I can get all the logs of the executed container. Appreciate any help as I'm not sure how I'd retrieve the logs from the container after calling display(), when looking at the sample code.

        ContainerCreateResponse container = client.container().createNew()
                .withName(containerName)
                .withImage(imageName)
                .done();

        try (
                OutputHandle logHandle = client.container().
                        withName(container.getId())
                        .logs()
                        .writingOutput(System.out)
                        .writingError(System.err)
                        .display()
        ) {

            if (client.container().withName(container.getId()).start()) {
                Thread.sleep(5000);
                 // Using Apache Commons IO to get the String.
                String output = IOUtils.toString(logHandle.getOutput(), "UTF-8");
                client.container().withName(container.getId()).remove();
                return output;
            }
        }