Java Class Find getClasses(Class clazz)

Description

get Classes

License

Open Source License

Declaration

@SuppressWarnings({ "rawtypes" })
    public static Class[] getClasses(Class clazz) 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.lang.reflect.Modifier;
import java.net.URL;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;

public class Main {
    @SuppressWarnings({ "rawtypes" })
    public static Class[] getClasses(Class clazz) throws ClassNotFoundException, IOException {
        if (clazz == null) {
            return new Class[0];
        }// w ww .  j  a  v  a  2 s.  c o m
        return getClasses(getPackageName(clazz));
    }

    /**
     * Source : http://www.dzone.com/snippets/get-all-classes-within-package
     * 
     * Scans all classes accessible from the context class loader which belong
     * to the given package and sub-packages.
     *
     * @param packageName
     *            The base package
     * @return The classes
     * @throws ClassNotFoundException
     * @throws IOException
     */
    @SuppressWarnings({ "rawtypes" })
    public static Class[] getClasses(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();
            System.out.println(resource.getFile());
            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()]);
    }

    /**
     * <p>
     * Gets the package name of a <code>Class</code>.
     * </p>
     *
     * @param clazz
     *            the class to get the package name for, may be
     *            <code>null</code>.
     * @return the package name or an empty string
     */
    @SuppressWarnings("rawtypes")
    public static String getPackageName(Class clazz) {
        if (clazz == null) {
            return "";
        }
        return getPackageName(clazz.getName());
    }

    /**
     * <p>
     * Gets the package name from a <code>String</code>.
     * </p>
     *
     * <p>
     * The string passed in is assumed to be a class name - it is not checked.
     * </p>
     * <p>
     * If the class is unpackaged, return an empty string.
     * </p>
     *
     * @param className
     *            the className to get the package name for, may be
     *            <code>null</code>
     * @return the package name or an empty string
     */
    public static String getPackageName(String className) {
        if (className == null || className.length() == 0) {
            return "";
        }

        // Strip array encoding
        while (className.charAt(0) == '[') {
            className = className.substring(1);
        }
        // Strip Object type encoding
        if (className.charAt(0) == 'L' && className.charAt(className.length() - 1) == ';') {
            className = className.substring(1);
        }

        int i = className.lastIndexOf(".");
        if (i == -1) {
            return "";
        }
        return className.substring(0, i);
    }

    /**
     * Source : http://www.dzone.com/snippets/get-all-classes-within-package
     * 
     * Recursive method used to find all classes in a given directory and
     * sub-directories.
     *
     * @param directory
     *            The base directory
     * @param packageName
     *            The package name for classes found inside the base directory
     * @return The classes
     * @throws ClassNotFoundException
     */
    @SuppressWarnings("rawtypes")
    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")) {
                Class clazz = Class
                        .forName(packageName + '.' + file.getName().substring(0, file.getName().length() - 6));
                System.out.println(clazz.isLocalClass() + " | " + clazz.isMemberClass());
                if (!clazz.isInterface() && !clazz.isMemberClass() && !Modifier.isAbstract(clazz.getModifiers())) {
                    classes.add(clazz);
                }
            }
        }
        return classes;
    }
}

Related

1. getAllClasses(ClassLoader cl, String packageName)
2. getAllClasses(String packageName)
3. getAllClassesFromPackage(final String packageName)
4. getAllClassesIn(String... packageNames)
5. getAllClassesInPackage(String packageName)
6. getClasses(Class cls)
7. getClasses(ClassLoader cl, String pack)
8. getClasses(final String packageName)
9. getClasses(final String packageName, final Class annotation)