FileUtils.java

package org.libresonic.player.util;

import org.apache.commons.lang.StringUtils;

import java.io.*;
import java.net.JarURLConnection;
import java.net.URL;
import java.net.URLConnection;
import java.util.Enumeration;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;

public class FileUtils {
    public static boolean copyFile(final File toCopy, final File destFile) {
        try {
            return FileUtils.copyStream(new FileInputStream(toCopy), new FileOutputStream(destFile));
        } catch (final FileNotFoundException e) {
            e.printStackTrace();
        }
        return false;
    }

    private static boolean copyFilesRecusively(
            final File toCopy, final File destDir
    ) {
        assert destDir.isDirectory();

        if (!toCopy.isDirectory()) {
            return FileUtils.copyFile(toCopy, new File(destDir, toCopy.getName()));
        } else {
            final File newDestDir = new File(destDir, toCopy.getName());
            if (!newDestDir.exists() && !newDestDir.mkdir()) {
                return false;
            }
            for (final File child : toCopy.listFiles()) {
                if (!FileUtils.copyFilesRecusively(child, newDestDir)) {
                    return false;
                }
            }
        }
        return true;
    }

    public static boolean copyJarResourcesRecursively(
            final File destDir, final JarURLConnection jarConnection
    ) throws IOException {

        final JarFile jarFile = jarConnection.getJarFile();

        for (final Enumeration<JarEntry> e = jarFile.entries(); e.hasMoreElements(); ) {
            final JarEntry entry = e.nextElement();
            if (entry.getName().startsWith(jarConnection.getEntryName())) {
                final String filename = StringUtils.removeStart(
                        entry.getName(), //
                        jarConnection.getEntryName());

                final File f = new File(destDir, filename);
                if (!entry.isDirectory()) {
                    final InputStream entryInputStream = jarFile.getInputStream(entry);
                    if (!FileUtils.copyStream(entryInputStream, f)) {
                        return false;
                    }
                    entryInputStream.close();
                } else {
                    if (!FileUtils.ensureDirectoryExists(f)) {
                        throw new IOException("Could not create directory: " + f.getAbsolutePath());
                    }
                }
            }
        }
        return true;
    }

    public static boolean copyResourcesRecursively(final URL originUrl, final File destination) {
        try {
            final URLConnection urlConnection = originUrl.openConnection();
            if (urlConnection instanceof JarURLConnection) {
                return FileUtils.copyJarResourcesRecursively(destination, (JarURLConnection) urlConnection);
            } else {
                return FileUtils.copyFilesRecusively(new File(originUrl.getPath()), destination);
            }
        } catch (final IOException e) {
            e.printStackTrace();
        }
        return false;
    }

    private static boolean copyStream(final InputStream is, final File f) {
        try {
            return FileUtils.copyStream(is, new FileOutputStream(f));
        } catch (final FileNotFoundException e) {
            e.printStackTrace();
        }
        return false;
    }

    private static boolean copyStream(final InputStream is, final OutputStream os) {
        try {
            final byte[] buf = new byte[1024];

            int len = 0;
            while ((len = is.read(buf)) > 0) {
                os.write(buf, 0, len);
            }
            is.close();
            os.close();
            return true;
        } catch (final IOException e) {
            e.printStackTrace();
        }
        return false;
    }

    private static boolean ensureDirectoryExists(final File f) {
        return f.exists() || f.mkdir();
    }
}