What code does the compiler generate for autoboxing?

Question

When the Java compiler autoboxes a primitive to the wrapper class, what code does it generate behind the scenes? I imagine it calls:

• The valueOf() method on t

Answer 1

I came up with a unit test that proves that Integer.valueOf() is called instead of the wrapper's constructor.

import static org.junit.Assert.assertNotSame;
import static org.junit.Assert.assertSame;

import org.junit.Test;

public class Boxing {
    @Test
    public void boxing() {
        assertSame(5, 5);
        assertNotSame(1000, 1000);
    }
}