Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Physics
Chemistry
Biology
Mathematics
English
Economics
Psychology
Social Studies
Fashion Studies
Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
What is the use of the Cleaner class in Java 9?
An Object that has been created during the program execution is automatically removed by Garbage Collector (GC). When an object not referenced by any thread and when JVM determines that this object can't be accessed, then it can be eligible for garbage collection.
The Object class has a finalize() method, which is automatically called by GC before it attempts to remove the object from the heap. In Java 9, the finalize() method has been deprecated and a new class java.lang.ref.Cleaner added to garbage collection management. An object of Cleaner class gets notified automatically when an object becomes eligible for garbage collection. An object that is being garbage collected needs to be registered with the cleaner object by using the register() method.
Example
import java.lang.ref.Cleaner;
public class CleanerTest {
public static void main(String args[]) {
System.out.println("TutorialsPoint");
Cleaner cleaner = Cleaner.create();
if(true) {
CleanerTest myObject = new CleanerTest();
cleaner.register(myObject, new State()); // register cleaner
}
for(int i = 1; i <= 10000; i++) {
String[] largeObject = new String[1000];
try {
Thread.sleep(1);
} catch(InterruptedException e) {
e.printStackTrace();
}
}
}
private static class State implements Runnable {
public void run() {
System.out.print("Cleaning action");
}
}
}Output
TutorialsPoint Cleaning action
638 Views
