{"id":12039,"date":"2018-03-29T05:12:34","date_gmt":"2018-03-29T05:12:34","guid":{"rendered":"https:\/\/data-flair.training\/blogs\/?p=12039"},"modified":"2026-05-28T18:09:33","modified_gmt":"2026-05-28T12:39:33","slug":"island-of-isolation-in-java","status":"publish","type":"post","link":"https:\/\/data-flair.training\/blogs\/island-of-isolation-in-java\/","title":{"rendered":"Island of Isolation in Java with Example"},"content":{"rendered":"

In our last tutorial, we discussed\u00a0Java Generics<\/a><\/strong>. Now, in this Java Island of Isolation tutorial, we are going to learn about what an island of isolation is in Java, which is a subpart of Java garbage collection. Moreover, we will discuss how to make an object eligible for Garbage collection.<\/p>\n

So, let us start the Island of Isolation in Java.<\/p>\n

\"Island<\/a>

The Island of Isolation in Java with Example<\/p><\/div>\n

The Island of Isolation in Java<\/h3>\n

In Java, object destruction is taken care of by the Garbage Collector module,<\/em> and the objects that don’t have any references to them are qualified for garbage collection. Java garbage collector is a specialist, proficient in distinguishing this sort of object.<\/p>\n

It refers to the object that is not reachable by any thread. Thus, placed in isolation without interaction with any process of an application. Then, the garbage collector notices those objects, and they pass the criteria for removal of those objects. If the objects contain references to each other, then only they are eligible for the garbage collector.<\/p>\n

When Object 1 references Object 2 and Object 2 references Object 1, but neither Object 1 nor Object 2 is referenced by any other object than that is an island of confinement.<\/p>\n

Essentially, an island of isolation in Java is a gathering of items that reference each other; however, they are not referenced by any dynamic object in the application. Entirely, even a solitary unreferenced object is an island of isolation as well.<\/p>\n

Do you know What is Java Garbage Collection?\u00a0<\/strong><\/a><\/p>\n

Example –<\/strong><\/p>\n

public class Test\r\n{\r\n\u00a0\u00a0\u00a0 Test i;\r\n\u00a0\u00a0\u00a0 public staticvoid main(String[] args)\u00a0\r\n\u00a0\u00a0\u00a0 {\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Test t1 = new Test();\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Test t2 = new Test();\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 t1.i = t2;\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 t2.i = t1;\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 t1 = null;\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 t2 = null;\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 System.gc();\r\n\u00a0\u00a0\u00a0 }\r\n\u00a0\u00a0\u00a0 @Override\r\n\u00a0\u00a0\u00a0 protected void finalize() throws Throwable\r\n\u00a0\u00a0\u00a0 {\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 System.out.println(\"Finalize method called\");\r\n\u00a0\u00a0\u00a0 }\r\n}<\/pre>\n
Explanation \u2013<\/strong><\/p>\n
Before destroying an object, the Garbage Collector calls the finalize method for maximum one number of times.<\/p>\n
Let’s revise the GC Algorithm in Java<\/strong><\/a><\/p>\n
The reason the finalize method is called twice in the above case is that two items are qualified for garbage collection. This is because we don’t have any outside references to t1 and t2 questions in the wake of executing t2=null.<\/p>\n
The total of what we have is just internal references (which are in instance variable I of class Test) to them of each other. It is extremely unlikely we can call the occurrence variable<\/a><\/strong> of the two articles. In this way, none of the items can be called once more.<\/p>\n