SymlinkResolver.java

package org.panbox.desktop.common.vfs;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;

import org.panbox.OS;
import org.panbox.PanboxConstants;


public final class SymlinkResolver {

    public static File resolveSymlinks(File file) {
        file = file.getAbsoluteFile();
        if (!OS.getOperatingSystem().isWindows()) {
            try {
                return file.getCanonicalFile();
            } catch (final IOException e) {
                return file;
            }
        }
        Process resolveSymlinks = null;
        try {
            resolveSymlinks = new ProcessBuilder(Files.resolveSymlinksWindows.toString()).start();
        } catch (final IOException e) {
            return file;
        }
        final String fileString = file.toString();
        try {
            final OutputStream stdin = resolveSymlinks.getOutputStream();
            stdin.write(fileString.getBytes(PanboxConstants.STANDARD_CHARSET));
            stdin.write('\n');
            stdin.flush();
        } catch (final Exception e) {
            return file;
        }
        final InputStream stdout = resolveSymlinks.getInputStream();
        final int length = fileString.length();
        final ByteArrayOutputStream buffer = new ByteArrayOutputStream(length);
        final byte[] buf = new byte[length];
        int read;
        while (true) {
            try {
                read = stdout.read(buf);
                if (read == -1) {
                    break;
                }
                buffer.write(buf, 0, read);
            } catch (final IOException e) {
                break;
            }
        }
        final byte[] finalFileBytes = buffer.toByteArray();
        try {
            return new File(new String(finalFileBytes, PanboxConstants.STANDARD_CHARSET));
        } catch (final UnsupportedEncodingException e) {
            return file;
        }
    }
}