Java Class Find getClassesAsList(String pckgname, Class type)

License

Declaration

@SuppressWarnings({ "unchecked", "rawtypes" })
    public static <A> List<Class<A>> getClassesAsList(String pckgname,
            Class<A> type) throws ClassNotFoundException 

Method Source Code

//package com.java2s;
/******************************************************************************
 * Copyright (C) 2009-2015  BIMserver.org
 * /*ww  w. j a va  2s . co m*/
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 * 
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *****************************************************************************/

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

public class Main {
    @SuppressWarnings({ "unchecked", "rawtypes" })
    public static <A> List<Class<A>> getClassesAsList(String pckgname,
            Class<A> type) throws ClassNotFoundException {
        ArrayList<Class<A>> classes = new ArrayList<Class<A>>();
        File directory = null;
        try {
            ClassLoader cld = Thread.currentThread()
                    .getContextClassLoader();
            if (cld == null) {
                throw new ClassNotFoundException("Can't get class loader.");
            }
            String path = pckgname.replace('.', '/');
            URL resource = cld.getResource(path);
            if (resource == null) {
                throw new ClassNotFoundException("No resource for " + path);
            }
            directory = new File(resource.getFile());
        } catch (NullPointerException x) {
            throw new ClassNotFoundException(pckgname + " (" + directory
                    + ") does not appear to be a valid package");
        }
        if (directory.exists()) {
            String[] files = directory.list();
            for (int i = 0; i < files.length; i++) {
                if (files[i].endsWith(".class")) {
                    Class forName = Class.forName(pckgname + '.'
                            + files[i].substring(0, files[i].length() - 6));
                    if (type.isAssignableFrom(forName) && type != forName) {
                        classes.add(forName);
                    }
                }
            }
        } else {
            throw new ClassNotFoundException(pckgname
                    + " does not appear to be a valid package");
        }
        return classes;
    }
}

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