Comments on: Java: Instantiate an innerclass from the main constructor does not works.

By: Michael

Michael — Wed, 04 Mar 2009 11:28:30 +0000

Hey,

Dit is een pure gok he, dus schiet me nie dood, geen programmas meer om het te testen :

public class Main
{
public static void main(String[] args)
{
Test t = this.new Test();

System.out.println(t.getInt());
}

private class Test
{
public Test()
{
}

public int getInt()
{
return 5;
}
}
}

By: Jan

Jan — Tue, 03 Mar 2009 23:58:32 +0000

Well the solution is to make it a static inner class so like this

public class Main {
public static class Test {
}
}

but then Test cannot access Main’s variables anymore.

By: Kristof

Kristof — Tue, 03 Mar 2009 23:55:10 +0000

@Jan no that does not work, (I tried it), and it actually makes sense, there is no ‘this’ variable in a static context.

So we’re still looking for a solution over here

By: Jan

Jan — Tue, 03 Mar 2009 22:04:53 +0000

The problem is that Java and C# handle their inner classes differently. Java inner classes have access to the members of the enclosing class. Thus you cannot construct the Main.Test class without having an instance of Main, and as you are in a static function you have no such reference, and this is what the error: “non-static variable this cannot be referenced from a static context” is telling you.

Test t = new Test() can be rewritten as Test t = this.new Test()

I hope this makes things clear.