What is an method in Java? Can it be overridden?

Question

<init> method can be found in stacktrace, for example. As I understood it represents initialization done in constructor.

If you try to execute

Object.class.getDeclaredMethod("<init>");

You'll get java.lang.NoSuchMethodException.

What is this method? When was it added to class? (in compilation - execution terms) Is it virtual, can one anyhow override it?

related: http://stackoverflow.com/q/8517121/1725096 – Jens Piegsa Dec 05 '13 at 17:55 — Jens Piegsa, Dec 05 '13 at 17:55

Kai Sternad · Accepted Answer · 2013-12-05T19:15:15.637

Have a look at the Java Virtual Machine Specification, chapter 2.9. It say on the <init> name:

At the level of the Java Virtual Machine, every constructor written in the Java programming language (JLS §8.8) appears as an instance initialization method that has the special name <init>. This name is supplied by a compiler. Because the name is not a valid identifier, it cannot be used directly in a program written in the Java programming language.

That's why <init> can be found on the stack trace, but is not accessible with code.

Stephen C · Answer 2 · 2013-12-05T17:58:51.677

7

What is an <init> method in Java?

It is a constructor. That's why you get a NoSuchMethodException when you try to call it as a method.

Can it be overriden?

No.

And if you see a <clinit> method, that is the classes static initialization "method".

edited Dec 05 '13 at 17:58

answered Dec 05 '13 at 17:47

Stephen C

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+1, but `` can also refer to initialization of instance fields - not just constructors. – Fabian Barney Dec 05 '13 at 17:51
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@FabianBarney it is partially true because initialization of instance fields happens at start of every constructor. – Pshemo Dec 05 '13 at 17:52
@Pshemo Ehrm, you're right! :-) – Fabian Barney Dec 05 '13 at 18:17

What is an method in Java? Can it be overridden?

2 Answers2