Java Class Find getAllClassesFromPackage(final String packageName)

Description

Load all classes from a package.

License

Open Source License

Parameter

Parameter	Description
packageName	a parameter

Exception

Parameter	Description
ClassNotFoundException	an exception
IOException	an exception

Declaration

public static Class[] getAllClassesFromPackage(final String packageName)
        throws ClassNotFoundException, IOException 

Method Source Code

//package com.java2s;
//License from project: Open Source License 

import java.io.File;
import java.io.IOException;
import java.net.URL;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;

public class Main {
    /**//from  www .  ja  v a 2s  . co  m
     * Load all classes from a package.
     * 
     * @param packageName
     * @return
     * @throws ClassNotFoundException
     * @throws IOException
     */
    public static Class[] getAllClassesFromPackage(final String packageName)
            throws ClassNotFoundException, IOException {
        ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
        assert classLoader != null;
        String path = packageName.replace('.', '/');
        Enumeration<URL> resources = classLoader.getResources(path);
        List<File> dirs = new ArrayList<File>();
        while (resources.hasMoreElements()) {
            URL resource = resources.nextElement();
            dirs.add(new File(resource.getFile()));
        }
        ArrayList<Class> classes = new ArrayList<Class>();
        for (File directory : dirs) {
            classes.addAll(findClasses(directory, packageName));
        }
        return classes.toArray(new Class[classes.size()]);
    }

    /**
     * Find file in package.
     * 
     * @param directory
     * @param packageName
     * @return
     * @throws ClassNotFoundException
     */
    public static List<Class<?>> findClasses(File directory, String packageName) throws ClassNotFoundException {
        List<Class<?>> classes = new ArrayList<Class<?>>();
        if (!directory.exists()) {
            return classes;
        }
        File[] files = directory.listFiles();
        for (File file : files) {
            if (file.isDirectory()) {
                assert !file.getName().contains(".");
                classes.addAll(findClasses(file, packageName + "." + file.getName()));
            } else if (file.getName().endsWith(".class")) {
                classes.add(Class
                        .forName(packageName + '.' + file.getName().substring(0, file.getName().length() - 6)));
            }
        }
        return classes;
    }
}

Related

1. findClassLocation(Class context)
2. findClassOriginFile(Class cls)
3. getAllAssignedClass(Class cls)
4. getAllClasses(ClassLoader cl, String packageName)
5. getAllClasses(String packageName)
6. getAllClassesIn(String... packageNames)
7. getAllClassesInPackage(String packageName)
8. getClasses(Class clazz)
9. getClasses(Class cls)