Jetty 9.x Embedded Example: loading a WebApp from a context.xml

b.xml

<?xml version="1.0" encoding="ISO-8859-1"?> 
<!DOCTYPE Configure PUBLIC "-//Jetty//Configure//EN" "http://www.eclipse.org/jetty/configure_9_0.dtd">
<Configure class="org.eclipse.jetty.webapp.WebAppContext">
  <Set name="contextPath">/r</Set>
  <Set name="war"><Property name="wars.base" default="test-wars"/>/webapp-b.war</Set>
</Configure>

WebAppFromXML.java

package jetty;

import java.io.File;
import java.io.InputStream;
import java.util.HashMap;
import java.util.Map;

import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.server.handler.DefaultHandler;
import org.eclipse.jetty.server.handler.HandlerList;
import org.eclipse.jetty.util.resource.Resource;
import org.eclipse.jetty.webapp.WebAppContext;
import org.eclipse.jetty.xml.XmlConfiguration;

public class WebAppFromXML
{
    public static void main(String[] args)
    {
        Server server = new Server(7080);
        HandlerList handlers = new HandlerList();
        server.setHandler(handlers);

        // Define some common environmental properties for XMLConfiguration to use
        File warsBase = new File("src/test/wars");
        Map<String, String> props = new HashMap<>();
        props.put("wars.base",warsBase.getAbsolutePath());

        try
        {
            // Load specific webapps
            handlers.addHandler(loadWebAppContext(new File(warsBase,"b.xml"),props));
            
            // lastly, add DefaultHandler for error handling
            handlers.addHandler(new DefaultHandler());

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

    private static WebAppContext loadWebAppContext(File contextXmlFile, Map<String, String> props) throws Exception
    {
        try
        {
            Resource contextXml = Resource.newResource(contextXmlFile.toURI());
            try (InputStream in = contextXml.getInputStream())
            {
                XmlConfiguration configuration = new XmlConfiguration(in);
                configuration.getProperties().putAll(props);
                return (WebAppContext)configuration.configure();
            }
        }
        catch (Exception e)
        {
            System.err.printf("Unable to load WebAppContext from: %s%n",contextXmlFile);
            throw e;
        }
    }
}