Is it possible to restrict synchronization to only a specific part of an object when using synchronized?

The synchronized keyword in Java locks the monitor of the object on which it is called. If you use synchronized on an object, the entire monitor of that object is locked, not just a part of its state.

However, you can limit the scope of synchronization by synchronizing not on the whole object, but on a specific internal object or code block that is responsible for a particular part of the data. For example, if you have an object with several fields and need to synchronize access to only one of them, you can create a separate lock object specifically for synchronizing that part.

Example:

private final Object lockForPart = new Object();

public void updatePart() {
    synchronized(lockForPart) {
        // code synchronized only for this part of the object
    }
}

Thus, synchronization is limited only to the area protected by a specific monitor, not the entire object.