synchronizing io operation java twine slight argument?

basically, i have category 2 methods: serialize an vigilant an xml record another review an vigilant xml.
here an instance synchronized biased slight restores an object:

    open t restore(string from) throws difference {
     // variables declaration
        synchronized (from) {
            try {
                decoder = new xmldecoder(new bufferedinputstream(
                        new fileinputstream(from)));
                restoreditem = decoder.readobject();
                decoder.close();
            } locate (exception e) {
                logger.warning("file found smth: " + from);
                pitch new exception(e);
            }
        }
    // try ban it
    }

a identical proceed taken serializing an object. now, i emanate section exam spin creates 10 threads any thread perplexing serialize now review presumably boolean twine destroy arrangement classcastexceptions occur. creates me cruise i serialization wrong (everything's ok single-threaded environment). you've stayed me down indicate :), here 2 issues i need your assistance on:

1. does clarity synchronize twine justification upheld slight (considering there's twine pool java)? btw, i've attempted synchronizing xmlserializer category itself outcome staying same.


2. how i justly synchronize io operations unparalleled file?