source: src/main/java/genius/domains/DomainInstaller.java@ 126

package genius.domains;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URISyntaxException;
import java.net.URL;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.security.CodeSource;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;

/**
 * Installs domain xml files either from jar file or from file system (if you
 * run from eclipse). Nothing happens if /etc is already there.
 *
 */
public class DomainInstaller {

        /**
         * Installs the domain files for use in Genius. Specifically, copies
         * "resources/genius/repositories/domains/domainrepository.xml" in "."
         * (current dir) and the entire directory "resources/genius/template" to
         * "./etc/". Files that are already exist are not touched. This means that
         * eg "./etc" already exists, nothing happens.
         * 
         * @throws IOException
         *             if failes to copy the files
         */
        public static void run() throws IOException {
                copyRecursively("genius/templates/", "etc/templates/");
                copyRecursively("genius/repositories/domains/domainrepository.xml", "domainrepository.xml");
        }

        /**
         * 
         * @param dir
         *            the head part of all files needed, eg "genius/templates/".
         * @param target
         *            the head part to be used for the target files. We replace
         *            "dir" with "target" in all matching files. Remember to add
         *            trailing "/" if you have trailing "/" in dir as well
         * @throws IOException
         * @throws URISyntaxException
         */
        protected static void copyRecursively(String dir, String target) throws IOException {
                // are we running from a jar?
                CodeSource src = DomainInstaller.class.getProtectionDomain().getCodeSource();
                if (src == null)
                        throw new FileNotFoundException("code base not found");
                URL uri = src.getLocation();
                // file://... but the file may be a jar after all..
                if (uri.toString().endsWith("jar")) {
                        copyJarSystem(dir, target, uri);
                } else {
                        // assume it's a normal file
                        copyFileSystem("/" + dir, target);
                }

        }

        /**
         * Copy a resource inside a JAR recursively
         * 
         * @param dir
         *            resource name, class path string like "/genius/repositories"
         * @param target
         *            target directory eg "test" (writes in current directory
         *            "./test"). Do not end the target with "/". If you copy just a
         *            file, give the exact target filename here.
         * @throws IOException
         *             if problem with reading or writing the file
         * @throws URISyntaxException
         *             if string can not be converted to valid file path
         */
        private static void copyFileSystem(String dir, String target) throws IOException {

                final Path destpath = Paths.get(target);
                if (destpath.toFile().exists()) {
                        return;
                }
                final URL url = DomainInstaller.class.getResource(dir);
                if (url == null) {
                        throw new FileNotFoundException("Could not find resource " + dir);
                }
                try {
                        final File file = new File(url.toURI());
                        if (file.isDirectory()) {
                                destpath.toFile().getParentFile().mkdirs();
                                Files.copy(Paths.get(url.toURI()), destpath);
                                for (File sub : file.listFiles()) {
                                        copyFileSystem(dir + "/" + sub.getName(), target + "/" + sub.getName());
                                }
                        } else {
                                Files.copy(Paths.get(url.toURI()), Paths.get(target));
                        }
                } catch (URISyntaxException e) {
                        throw new IOException("Encountered wrong filename while copying resources", e);
                }

        }

        /**
         * Copy all files recursively where the source is inside a jar.
         * 
         * @param dir
         * @param target
         * @param uri
         * @throws IOException
         */
        private static void copyJarSystem(String dir, String target, URL uri) throws IOException {
                final Path destpath = Paths.get(target);
                if (destpath.toFile().exists()) {
                        return;
                }
                ZipInputStream zip = new ZipInputStream(uri.openStream());
                while (true) {
                        ZipEntry e = zip.getNextEntry();
                        if (e == null)
                                break;
                        String name = e.getName();
                        if (name.startsWith(dir)) {
                                copyResource("/" + name, name.replace(dir, target));
                        }
                }
        }

        /**
         * Copy 1 resource inside a jar. If given name actually ends with "/" it is
         * assumed a directory and the directory is created if it does not yet
         * exist.
         * 
         * @param name
         *            the file/directory name.Name should end with "/" iff it is a
         *            directory.
         * @param target
         *            the target name/directory.
         * @throws IOException
         */
        private static void copyResource(String name, String target) throws IOException {
                /*
                 * make the directory that should hold this file. Notice: sometimes the
                 * zip file contains the directories in "nice" order so that dir names
                 * are before files inside these dirs. And at other times, they are
                 * not...
                 */
                createDir(new File(target));
                if (name.endsWith("/")) {
                        return;
                }

                InputStream stream = null;
                OutputStream resStreamOut = null;
                try {
                        stream = DomainInstaller.class.getResourceAsStream(name);
                        if (stream == null) {
                                throw new FileNotFoundException("file not found " + name);
                        }
                        int readBytes;
                        byte[] buffer = new byte[4096];
                        resStreamOut = new FileOutputStream(target);
                        while ((readBytes = stream.read(buffer)) > 0) {
                                resStreamOut.write(buffer, 0, readBytes);
                        }
                } finally {
                        if (stream != null) {
                                stream.close();
                        }
                        if (resStreamOut != null) {
                                resStreamOut.close();
                        }
                }
        }

        private static void createDir(File dir) {
                if (dir == null)
                        return;
                if (!dir.isDirectory()) {
                        dir = dir.getParentFile();
                        if (dir == null)
                                return;
                }
                dir.mkdirs();
        }

}