Java threads locking on a specific object

Question

I have a web application and I am using Oracle database and I have a method basically like this:

public static void saveSomethingImportantToDataBase(Object t         


        

Answer 1

To answer your question about locking the Integer, the short answer is NO - it won't prevent threads with another Integer instance with the same value from entering. The long answer: depends on how you obtain the Integer - by constructor, by reusing some instances or by valueOf (that uses some caching). Anyway, I wouldn't rely on it.

A working solution that will work is to make the method synchronized:

public static synchronized void saveSomethingImportantToDataBase(Object theObjectIwantToSave) {
    if (!methodThatChecksThatObjectAlreadyExists) {
        storemyObject() //pseudo code
    }
    // Have to do a lot other saving stuff, because it either saves everything or nothing
    commit() // pseudo code to actually commit all my changes to the database.
}

This is probably not the best solution performance-wise, but it is guaranteed to work (note, if you are not in a clustered environment) until you find a better solution.