That's very nifty, Norman. This is a simultaneously inspiring and
depressing reminder that despite having used Tapestry since version 3, I
still feel like a total noob. :-) I'd love to see a blog series on
"Services you never knew about and fun things to do with them!"
Michael
On 15 August 2012 18:33, Norman Franke <nor...@myasd.com> wrote:
> Something similar was asked in another thread, but I figured others may
> find this helpful.
>
> I wanted to automatically bind my interfaces and implementations of my
> numerous DAOs in my AppModule. It's pretty easy, so here is what I idd.
> This is called from the bind static method. Obviously you'd need to change
> the package names. My naming convention is to put the implementation
> packages in a sub ".impl" package, e.g. com.myasd.db.dao.impl in my case.
> Classes then are suffixed with "Impl" to make Eclipse's package
> auto-complete suggestions work better. I've been using this for a few
> years, at lest.
>
> @SuppressWarnings({ "unchecked", "rawtypes" })
> static void bindDAOs(ServiceBinder binder) {
> try {
> ClassLoader contextClassLoader =
> Thread.currentThread().getContextClassLoader();
> List<Class<?>> daos =
> PackageEnumerator.getClassesForPackage("com.myasd.db.dao");
> for (Class<?> dao : daos) {
> String pkg = dao.getPackage().getName();
> String cls = dao.getSimpleName();
> try {
> Class impl =
> contextClassLoader.loadClass(pkg+".impl."+cls+"Impl");
> binder.bind(dao, impl).scope(ScopeConstants.PERTHREAD);
> } catch (ClassNotFoundException e) {
> // Ignore, we just won't bind that class.
> }
> }
> } catch (ClassNotFoundException e) {
> e.printStackTrace();
> }
> }
>
>
> Helper method borrowed from who-knows-where:
>
> public static List<Class<?>> getClassesForPackage(String packageName)
> throws ClassNotFoundException {
> // This will hold a list of directories matching the pckgname.
> // There may be more than one if a package is split over multiple
> // jars/paths
> List<Class<?>> classes = new ArrayList<Class<?>>();
> ArrayList<File> directories = new ArrayList<File>();
> try {
> ClassLoader cld =
> Thread.currentThread().getContextClassLoader();
> if (cld == null) {
> throw new ClassNotFoundException("Can't get class
> loader.");
> }
> // Ask for all resources for the path
> Enumeration<URL> resources =
> cld.getResources(packageName.replace('.', '/'));
> while (resources.hasMoreElements()) {
> URL res = resources.nextElement();
> if (res.getProtocol().equalsIgnoreCase("jar")) {
> JarURLConnection conn = (JarURLConnection)
> res.openConnection();
> JarFile jar = conn.getJarFile();
> for (JarEntry e : Collections.list(jar.entries())) {
>
> if
> (e.getName().startsWith(packageName.replace('.', '/')) &&
> e.getName().endsWith(".class")
> && !e.getName().contains("$")) {
> String className = e.getName().replace("/",
> ".").substring(0, e.getName().length() - 6);
> System.out.println(className);
> classes.add(Class.forName(className));
> }
> }
> } else
> directories.add(new
> File(URLDecoder.decode(res.getPath(), "UTF-8")));
> }
> } catch (NullPointerException x) {
> throw new ClassNotFoundException(packageName + " does not
> appear to be "
> + "a valid package (Null pointer exception)");
> } catch (UnsupportedEncodingException encex) {
> throw new ClassNotFoundException(packageName + " does not
> appear to be "
> + "a valid package (Unsupported encoding)");
> } catch (IOException ioex) {
> throw new ClassNotFoundException("IOException was thrown when
> trying " + "to get all resources for "
> + packageName);
> }
>
> // For every directory identified capture all the .class files
> for (File directory : directories) {
> if (directory.exists()) {
> // Get the list of the files contained in the package
> String[] files = directory.list();
> for (String file : files) {
> // we are only interested in .class files
> if (file.endsWith(".class")) {
> // removes the .class extension
> classes.add(Class.forName(packageName + '.' +
> file.substring(0, file.length() - 6)));
> }
> }
> } else {
> throw new ClassNotFoundException(packageName + " (" +
> directory.getPath()
> + ") does not appear to be a valid package");
> }
> }
> return classes;
> }
>
> Norman Franke
> Answering Service for Directors, Inc.
> www.myasd.com
>
>
>
>
