Tapestry-5.3.1 and Jboss-7.0.2-Final

The Java web framework Tapestry 5 has a hot deployment/reload feature, that traverses the classpath, looking for new resources to load. Unfortunately, it is not capable to parse URLs of Jboss’ virtual file system and therefore does not find it’s own core libraries. This issue has been tracked in TAP5-576 and a solution for Jboss-5 and Jboss-6 can be found in the corresponding wiki articles. The same problem remains for Jboss-7. Accidentally the reflective calls to virtual file are restricted. But the solution for Jboss-6.1 does still work. Here is a little tutorial how to achieve this.

Add the following dependency to the maven pom of your tapestry web project:

<dependency>
	<groupId>org.jboss</groupId>
	<artifactId>jboss-vfs</artifactId>
	<version>3.0.1.GA</version>
	<scope>provided</scope>
</dependency>

Add a class responsible for converting vfs URLs to physical URLs:

/**
 * Supports the special vfs* URLs used by class loaders of JBoss 7.0.2.
 * 
 * @author Benjamin Bentmann
 * @author <a href="mailto:simon.dierl@cs.tu-dortmund.de">Simon Dierl</a>
 * @author <a
 *         href="http://wiki.apache.org/tapestry/HowToRunTapestry5OnJBoss6Dot1"
 *         >Tapestry Wiki</a>
 * @author Johannes Neubauer
 * @see <a href="https://issues.apache.org/jira/browse/TAP5-576">TAP5-576</a>
 */
public class JBoss7ClasspathURLConverterImpl implements ClasspathURLConverter {
	/**
	 * Logger for this class.
	 */
	private static final Logger LOGGER = Logger.getLogger(JBoss7ClasspathURLConverterImpl.class);
	@Override
	public URL convert(final URL url) {
		if ((url != null) && url.getProtocol().startsWith("vfs")) {
			try {
				final URL realURL;
				final String urlString = url.toString();
				// If the virtual URL involves a JAR file,
				// we have to figure out its physical URL ourselves because
				// in JBoss 7.0.2 the JAR files exploded into the VFS are empty
				// (see https://issues.jboss.org/browse/JBAS-8786).
				// Our workaround is that they are available, unexploded,
				// within the otherwise exploded WAR file.
				if (urlString.contains(".jar")) {
					// An example URL:
					// "vfs:/devel/jboss-6.1.0.Final/server/default/deploy/myapp.ear/myapp.war/WEB-INF/\
					// lib/tapestry-core-5.2.6.jar/org/apache/tapestry5/corelib/components/"
					// Break the URL into its WAR part, the JAR part,
					// and the Java package part.
					final int warPartEnd = urlString.indexOf(".war") + 4;
					final String warPart = urlString.substring(0, warPartEnd);
					final int jarPartEnd = urlString.indexOf(".jar") + 4;
					final String jarPart = urlString.substring(warPartEnd, jarPartEnd);
					final String packagePart = urlString.substring(jarPartEnd);
					// Ask the VFS where the exploded WAR is.
					final URL warURL = new URL(warPart);
					final URLConnection warConnection = warURL.openConnection();
					final VirtualFile jBossVirtualWarDir = (VirtualFile) warConnection.getContent();
					final File physicalWarDir = jBossVirtualWarDir.getPhysicalFile();
					final String physicalWarDirStr = physicalWarDir.toURI().toString();
					// Return a "jar:" URL constructed from the parts
					// eg.
					// "jar:file:/devel/jboss-6.1.0.Final/server/default/tmp/vfs/automount40a6ed1db5eabeab/\
					// myapp.war-43e2c3dfa858f4d2//WEB-INF/lib/tapestry-core-5.2.6.jar!/org/apache/tapestry5/corelib/components/".
					final String actualJarPath = "jar:" + physicalWarDirStr + jarPart + "!" + packagePart;
					return new URL(actualJarPath);
				}
				// Otherwise, ask the VFS what the physical URL is...
				else {
					final URLConnection connection = url.openConnection();
					final VirtualFile virtualFile = (VirtualFile) connection.getContent();
					realURL = VFSUtils.getPhysicalURL(virtualFile);
				}
				return realURL;
			}
			catch (final Exception e) {
				LOGGER.fatal("Unable to convert URL " + url, e);
			}
		}
		return url;
	}
}

Afterwards register the custom URL converter to Tapestry via the AppModule:

public static void contributeServiceOverride(MappedConfiguration<Class, Object> configuration) {
	configuration.add(ClasspathURLConverter.class, new JBoss7ClasspathURLConverterImpl());
}

This should do the job.

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