What types of links are used in Java?

In Java, there are several types of references that manage the lifetime of objects and their garbage collection:

• Strong Reference — a normal reference to an object. As long as strong references exist, the object will not be garbage collected.

• Soft Reference — used for caching. An object with a soft reference will only be removed when the memory is low.

• Weak Reference — an object with such a reference can be garbage collected in the next garbage collection cycle, even if the reference still exists.

• Phantom Reference — used to track when an object is ready to be collected but has not yet been removed.

Example of using a weak reference:

WeakReference<MyObject> weakRef = new WeakReference<>(new MyObject());
MyObject obj = weakRef.get();
if (obj != null) {
    // object is still accessible
} else {
    // object has been garbage collected
}