FileInputStream in = new FileInputStream(file);
try {
    java.nio.channels.FileLock lock = in.getChannel().lock();
    try {
        Reader reader = new InputStreamReader(in, charset);
        ...
    } finally {
        lock.release();
    }
} finally {
    in.close();
}

FileInputStream in = new FileInputStream(file);
try {
    // Correct way to obtain shared lock?
    java.nio.channels.FileLock sharedLock = in.getChannel().lock(0L, Long.MAX_VALUE, true);
    try {
        Reader reader = new InputStreamReader(in, charset);
        ...
    } finally {
        sharedLock.release();
    }
} finally {
    in.close();
}