configure jetty 9.3.0 embedded (programmatically) with caching

Question

I can't seem to get my jetty to work with caching. I have a jetty server that will display html only. I have JavaScripts in there and a lot of images which I don't want to load every time. For example my application needs to switch in 10 seconds between 3 pages. Loading jQuery three times is time consuming and loading the logo picture and all that takes even longer. That's why I want to enable Caching.

This is what I got:

server = new Server(); //new Jetty Server
//setting up a ssl connection
try
{
    SslContextFactory cf = new SslContextFactory();
    cf.setKeyStorePath(keystore);
    cf.setKeyStorePassword("password");
    
    HttpConfiguration config = new HttpConfiguration();
    config.addCustomizer(new SecureRequestCustomizer());
    config.setSecureScheme("https");
    config.setSecurePort(8443);
    
    HttpConfiguration sslConfiguration = new HttpConfiguration(config);
    sslConfiguration.addCustomizer(new SecureRequestCustomizer());
    
    httpConnector = new ServerConnector(server);
    httpConnector.addConnectionFactory(new HttpConnectionFactory(config));
    httpConnector.setPort(suggestHttpPort());
    httpConnector.setName("unsecured");
    sslConnector = new ServerConnector(server, 
            new SslConnectionFactory(cf, HttpVersion.HTTP_1_1.toString()), 
            new HttpConnectionFactory(sslConfiguration));
    sslConnector.setPort(suggestHttpSSLPort());
    sslConnector.setName("secured");
    
    server.setConnectors(new Connector[] { httpConnector, sslConnector });  
}
catch (Exception e)
{
    log.error("setting up Jetty failed", e);
}
// This is where i want to enable caching, at least that is what i have figuged out so far but its not working
DefaultServlet defaultServlet = new DefaultServlet();
ServletHolder holder = new ServletHolder(defaultServlet);
holder.setInitParameter("cacheControl", "max-age=120, public");
ServletContextHandler bb = new ServletContextHandler();
bb.addServlet(holder, "/");
server.setHandler(bb);
server.start();

What am I doing wrong? I want to enable caching for everything...

Answer 1

Don't use ServletHolder directly like that against a started Servlet, let the ServletHolder create and init the class reference instead.

You'll want a ServletContextHandler and a defined Base Resource that the DefaultServlet can utilize as well (this should be a URI pointing to the root of your static file content)

Example:

ServletContextHandler context = new ServletContextHandler();
context.setContextPath("/");
context.setBaseResource(Resource.newResource(webRootUri));

ServletHolder holderPwd = new ServletHolder("default", DefaultServlet.class);
holderPwd.setInitParameter("dirAllowed", "true");
holderPwd.setInitParameter("cacheControl", "max-age=3600,public");
context.addServlet(holderPwd,"/");
server.setHandler(context);