Java Class Loader getClassLoader(File[] directories)

Description

get Class Loader

License

Apache License

Declaration

public static ClassLoader getClassLoader(File[] directories)
            throws Exception 

Method Source Code

//package com.java2s;
/*******************************************************************************
 * Copyright 2010 Sudhir Movva/*w ww  .  java  2 s.  c  o  m*/
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 ******************************************************************************/

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

public class Main {
    public static ClassLoader getClassLoader(File[] directories)
            throws Exception {

        ClassLoader cl = null;
        if (directories == null || directories.length == 0) {
            System.out.println("Directory is null or 0 length");
            return cl;
        }

        ArrayList urlList = new ArrayList();

        for (int i = 0; i < directories.length; i++) {
            File directory = directories[i];
            if (directory == null || !directory.exists()
                    || !directory.isDirectory() || !directory.canRead()) {
                System.out.println("Is not a directory");
                continue;
            }
            String filesList[] = directory.list();
            if ((filesList != null) && (filesList.length > 0)) {
                for (int j = 0; j < filesList.length; j++) {
                    String fileName = filesList[j].toLowerCase();
                    if (fileName.endsWith(".jar")) {
                        System.out.println("fileName is " + fileName);
                        if (!"dbutil.jar".toLowerCase().equals(fileName)) {
                            File file = new File(directory, filesList[j]);
                            URL url = new URL("file", null,
                                    file.getCanonicalPath());
                            System.out.println("url added is "
                                    + url.toExternalForm());
                            urlList.add(url);
                        }
                    }

                }
            }

        }
        URL arrayUrlList[] = (URL[]) urlList
                .toArray(new URL[urlList.size()]);
        System.out
                .println("The final array of url size is " + arrayUrlList);
        cl = new URLClassLoader(arrayUrlList);
        return cl;
    }
}

Related

1. createFallbackClassLoader(Collection files)
2. dumpClassLoader(ClassLoader cl, PrintWriter out)
3. getClass(Object classLoaderMakedObject, File file, String targetClass)
4. getClassInputStream(String className, ClassLoader cl)
5. getClassLoader()
6. getClassLoader(String path)
7. getClassLoaderForClass(final Class clazz)
8. getClassLoaderForDirectory(final File baseFolder)
9. getClassloaderRootDir(Class forClass)