为什么下面的Java代码会给出StackOverflow错误？

Question

I am getting StackOverflow error while executing the below:

public class StackOverflow7 {
    StackOverflow7 obj = new StackOverflow7();
    int finalCount = 0;
    public static void main(String[] args) {
        for(int i = 1 ; i <= 5 ; i++)
        System.out.println(i);

        StackOverflow7 localObj = new StackOverflow7();
        localObj.count(88);
        System.out.println("Final Count :: " + localObj.finalCount);
    }

    private void count(int num){
        finalCount = finalCount + num;
    }
}

Answer 1

This line:

StackOverflow7 obj = new StackOverflow7();

is always called when you create an object of StackOverflow7 , which you are doing in this line itself. Thus, this line recursively calls itself, until you get a StackOverflow error.

Answer 2

You get the stack overflow because of this line: StackOverflow7 obj = new StackOverflow7(); . Whenever you create a new instance, it is called and thus you create a new instance and create a new instance and so on. In your stack trace you should thus see a lot of <clinit> lines.

You start the whole thing by calling StackOverflow7 localObj = new StackOverflow7(); in your main method.

To fix this either make obj a static field or remove it altogether, since you're not using it anyways.

Answer 3

Because of this line:

StackOverflow7 obj = new StackOverflow7();

Every time you create a new object this line will executet and try to create an other object