This class is responsible for finding all of the classes within a package path. This does not work for remote packages. This code was based on the work found here: http://svn.apache.org/repos/asf/incubator/chukwa/trunk/src/main/java/org/apache/hadoop/chukwa/util/ClassUtils.java http://tapestry.1045711.n5.nabble.com/T5-Auto-Binding-of-DAOs-td5715…

gistfile1.txt

import com.google.common.base.Preconditions;

import java.io.File;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.JarURLConnection;
import java.net.URL;
import java.net.URLDecoder;
import java.util.*;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;

public class ClassFinder {

    public static String[] findClasses(String packageName)
            throws ClassNotFoundException {
        Preconditions.checkNotNull(packageName);
        Preconditions.checkArgument(!packageName.isEmpty());

        Set<String> classes = new HashSet<>();
        ArrayList<File> directories = new ArrayList<>();

        // Get a File object for the package
        try {
            ClassLoader cld = Thread.currentThread().getContextClassLoader();
            if (cld == null) {
                throw new ClassNotFoundException("Can't get class loader.");
            }
            String path = packageName.replace('.', '/');

            // Ask for all resources for the path
            Enumeration<URL> resources = cld.getResources(path);
            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())) {
                        String curName = e.getName();
                        if (curName.startsWith(packageName.replace('.', '/'))
                                && curName.endsWith(".class") && !curName.contains("$")) {
                            String className =
                                    e.getName().replace("/", ".").substring(0, curName.length() - 6);
                            //       System.out.println(className);
                            classes.add(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 (File directory : directories) {
            if (directory.exists()) {
                // Get the list of the files contained in the package
                String[] files = directory.list();
                for (String cName : files) {
                    if (cName.toLowerCase().endsWith(".class")) {
                        cName = packageName + "."+ cName.substring(0, cName.length() - 6);
                        cName = cName.replaceAll("\\.\\.", "\\.");
                        classes.add(cName);
                    }

                }
            } else {
                throw new ClassNotFoundException(packageName + " does not appear to be a valid package");
            }
        }

        return classes.toArray(new String[classes.size()]);

    }
}