Is It Possible/How to Embed and Access HTML Files in a Jar

Is it possible/how to embed and access HTML Files in a JAR?

File manual = new File(getClass().getResource("/manual/help.html").toURI());

That is where it goes wrong. Java cannot create a File object from an embedded-resource

Keep it as an URL and use that for setPage(..).

As to the more general problem.

HTML from a Jar file that links resources (e.g. CSS or images) by relative references will work just fine.

E.G.

This example loads HTML (that has a relative reference to an image) from a Jar.

import javax.swing.*;
import java.net.URL;

class ShowHtml {

    public static void main(String[] args) {
        final String address =
            "jar:http://pscode.org/jh/hs/object.jar!/popup_contents.html";
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                try {
                    URL url = new URL(address);
                    JEditorPane jep = new JEditorPane(url);
                    JFrame f = new JFrame("Show HTML in Jar");
                    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                    f.add(new JScrollPane(jep));
                    f.pack();
                    f.setSize(400,300);
                    f.setLocationByPlatform(true);
                    f.setVisible(true);
                } catch(Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }
}

Screenshot

JEditorPane displaying Jar'd HTML

HTML

The HTML that is being loaded.

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN">
<!--       
 *        Copyright (C) 1997  Sun Microsystems, Inc
 *                    All rights reserved.
 *          Notice of copyright on this source code 
 *          product does not indicate publication. 
 * 
 * RESTRICTED RIGHTS LEGEND: Use, duplication, or disclosure by 
 * the U.S. Government is subject to restrictions as set forth 
 * in subparagraph (c)(1)(ii) of the Rights in Technical Data
 * and Computer Software Clause at DFARS 252.227-7013 (Oct. 1988) 
 * and FAR 52.227-19 (c) (June 1987).
 *
 *    Sun Microsystems, Inc., 2550 Garcia Avenue,
 *    Mountain View, California 94043.
 *
-->
<HTML>
<HEAD>
<TITLE>
Editing Project Attributes
</TITLE>
</HEAD>
<BODY BGCOLOR="#ffffff">
<IMG SRC="images/popup_icon.gif" width="24" height="24"> <b>Popup Window</b>
<p>
Popup windows appear near the location from which they are
activated.  They are not contained in frames and thus
cannot be resized or moved by the user.  Popups are
dismissed by clicking anywhere in the help viewer.
<p>
Popup windows can be activated by clicking on a text object, 
graphic object, or JComponent button.  All three examples are
included in this demo.
<p>
<A HREF="popup_contents2.html">More...</A>
</body>
</html>

E.G. 2

For dynamically created HTML, the JRE will probably use the class file's location as the presumed location of the HTML. But to remove all doubt, we can specify the base element in the head.

import javax.swing.*;

class HtmlUsingBase {

    public static void main(String[] args) {
        final String htmlContent =
            "<html>" +
            "<head>" +
            "<base href='http://www.gravatar.com/'>" +
            "</head>" +
            "<body>" +
            "<h1>Image path from BASE</h1>" +
            "<img src='avatar/a1ab0af4997654345d7a9" +
            "49877f8037e?s=128&d=identicon&r=PG'" +
            " width='128' height='128'>" +
            "</body>" +
            "</html>";
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                JLabel label = new JLabel(htmlContent);
                JOptionPane.showMessageDialog(null, label);
            }
        });
    }
}

Screenshot

Sample Image

Embed HTML in JAR with Eclipse

I was using the Package required libraries into generated JAR, but I had to use Extract required libraries into generated JAR. I don't know why yet.

When I used the Packagemethod, java used to look for style.css in the root of the JAR file, no matter where the HTML file was located.

Export menu

How to get embedded Jetty serving html files from a Jar, not a War

You need to set the Resource Base for the Context to the URL/URI to where your static content can be accessed from.

Note: you set this at the ServletContext level, not the DefaultServlet level, that way all servlets in your context have access to the same information and the various methods in ServletContext related to real file paths and resources are sane.

public static void main(String[] args) throws Exception
{
    Server server = new Server(8080);

    // Figure out what path to serve content from
    ClassLoader cl = MyEmbeddedJettyMain.class.getClassLoader();
    // We look for a file, as ClassLoader.getResource() is not
    // designed to look for directories (we resolve the directory later)
    URL f = cl.getResource("static-root/hello.html");
    if (f == null)
    {
        throw new RuntimeException("Unable to find resource directory");
    }

    // Resolve file to directory
    URI webRootUri = f.toURI().resolve("./").normalize();
    System.err.println("WebRoot is " + webRootUri);

    ServletContextHandler context = new ServletContextHandler(ServletContextHandler.SESSIONS);
    context.setContextPath("/");
    context.setBaseResource(Resource.newResource(webRootUri));
    context.setWelcomeFiles(new String[]{"welcome.html"});

    ServletHolder holderPwd = new ServletHolder("default", DefaultServlet.class);
    holderPwd.setInitParameter("dirAllowed","true");
    context.addServlet(holderPwd,"/");

    server.setHandler(context);

    server.start();
    server.join();
}

Open an HTML File Inside a .JAR File

You'll have to devompress the file first.

Something like:

public static void main(String[] args) throws IOException, URISyntaxException {
    URL url = Snake.class.getResource("/WebContent/snake.html");

    File temp = File.createTempfile();
    temp.deleteOnExit();

    // Copy content 

    Desktop.getDesktop().browse(temp.getAbsolutePath());
}

How can I add policy file to the jar applet which is embedded in html file

If your HTML could insert a policy file like that to my machine, it would be an huge security bug. Fortunately, to the best of my knowledge, it is not possible.

If an applet needs trust, digitally sign it.

Is It Possible/How to Embed and Access HTML Files in a Jar