CODEWITHSUNDEEP
java
Konstantin Weitz
Konstantin Weitz

Reputation: 6422

Why does Java limit the size of a method to 65535 byte?

I just compiled the following code

public class A {
    public static void main(String... args) {
        int i = 3;
        ++i; 
        ++i;
        ++i;
        ++i;
        ++i;
        ++i;
        ++i;
        ++i;
        // repeat writing the expression ++i for 20,000 times

        System.out.println(i);
    }
}

And got the following error message

The code of method main(String...) is exceeding the 65535 bytes limit

Why does Java implement this limit? I don't see the rational since Java does include a goto_w instruction.

Upvotes: 19

Views: 19824

Answers (1)

WhiteFang34
WhiteFang34

Reputation: 72039

See the Java Virtual Machine Specification section 4.10:

4.10 Limitations of the Java Virtual Machine

  • The amount of code per non-native, non-abstract method is limited to 65536 bytes by the sizes of the indices in the exception_table of the Code attribute (§4.7.3), in the LineNumberTable attribute (§4.7.8), and in the LocalVariableTable attribute (§4.7.9).

There's few good reasons to have a method that long in an object-oriented programming language.

Upvotes: 26

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