3. What is the difference between final, finally, and finalize?

One, final immutable

Usually used to modify a class or a method or a variable

1. When modifying a class, it means that this class cannot be inherited.(Avoid overriding methods, change some functions)

2. When modifying a method, it means that this method cannot be overridden.(same as above)

3. When modifying a variable, it means that the reference to this variable cannot be changed.(Ensure that the value of the variable is correct and avoid being modified randomly)

Second, finally the last

It is usually used with try-catch block to ensure that the last one is processed after some business is processed, such as closing the database connection and waiting.Normally it will be implemented.

Note: It may not be executed. For example, an infinite loop while(true) is used in try or the program System.exit(1), System.exit(0) is exited in advance.

System.exit(0): exit normally

System.exit(1): Abnormal exit

Three, finalize completed

A method of java.lang.obejct, which is used to reclaim some specific resources before the object is reclaimed by the garbage processor.