Adds the jars in the given directory to classpath - Android Hardware

Android examples for Hardware:Directory

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Description

Adds the jars in the given directory to classpath

Demo Code


import java.io.File;
import java.io.IOException;
import java.lang.reflect.Method;
import java.net.URI;
import java.net.URL;
import java.net.URLClassLoader;
import org.apache.log4j.Logger;

public class Main{
    private static Logger LOGGER = Logger.getLogger(ClasspathUtils.class
            .getName());/*from   w w w. j a v  a 2s.c om*/
    @SuppressWarnings("rawtypes")
    private static final Class[] parameters = new Class[] { URL.class };
    /**
     * Adds the jars in the given directory to classpath
     * 
     * @param directory
     * @throws IOException
     */
    public static void addDirToClasspath(File directory) throws IOException {
        if (directory.exists()) {
            ClasspathUtils.LOGGER.info("adding directory to classpath: "
                    + directory.getAbsolutePath());
            File[] files = directory.listFiles();
            for (int i = 0; i < files.length; i++) {
                File file = files[i];
                URI uri = file.toURI();
                String path = uri.getPath();
                if (path.endsWith(".jar")) {
                    ClasspathUtils.addURL(file.toURI().toURL());
                }
            }
        } else {
            ClasspathUtils.LOGGER.warn("The directory \"" + directory
                    + "\" does not exist!");
        }
    }
    /**
     * Add URL to CLASSPATH
     * 
     * @param u
     *            URL
     * @throws IOException
     *             IOException
     */
    public static void addURL(URL u) throws IOException {
        ClasspathUtils.LOGGER.info("adding to classpath");
        URLClassLoader sysLoader = (URLClassLoader) ClassLoader
                .getSystemClassLoader();
        URL urls[] = sysLoader.getURLs();

        ClasspathUtils.LOGGER.info(urls.length);
        if (ClasspathUtils.isURLInClassPath(urls, u)) {
            ClasspathUtils.LOGGER.info("already in classpath: " + u);
            return;
        }

        Class<URLClassLoader> sysclass = URLClassLoader.class;
        try {
            Method method = sysclass.getDeclaredMethod("addURL",
                    ClasspathUtils.parameters);
            method.setAccessible(true);
            method.invoke(sysLoader, new Object[] { u });
        } catch (Throwable t) {
            t.printStackTrace();
            throw new IOException(
                    "Error, could not add URL to system classloader");
        }
    }
    public static boolean isURLInClassPath(URL[] urls, URL u) {
        for (int i = 0; i < urls.length; i++) {
            if (urls[i].toString().equalsIgnoreCase(u.toString())) {
                ClasspathUtils.LOGGER.info("URL " + u
                        + " is already in the CLASSPATH");
                return true;
            }
        }
        return false;
    }
}

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