In Java, 'equals' and '==' test code

EqualTest.java

public class EqualTest{
     public static void main(String []args){
         new EqualTest().test();
     }
     private void test() {
        Dummy obj1 = new Dummy(1, 10.0);
        Dummy obj2 = new Dummy(2, 20.0);
        Dummy obj3 = new Dummy(1, 10.0);
        
        System.out.println("obj1 == obj2: " + (obj1 == obj2) + " / obj1.equals(obj2): " + obj1.equals(obj2) );
        System.out.println("obj1 == obj3: " + (obj1 == obj3) + " / obj1.equals(obj3): " + obj1.equals(obj3) );
     }
     
     class Dummy {
         private int data1;
         private double data2;
         
         public Dummy() {
             
         }
         
         public Dummy(int data1, double data2) {
             this.data1 = data1;
             this.data2 = data2;
         }
         
         public void setData1(int data1) {
             this.data1 = data1;
         }
         
         public void setData2(double data2) {
             this.data2 = data2;
         }
         
         public int getData1() {
             return data1;
         }
         
         public double getData2() {
             return data2;
         }
         
         public boolean equals(Dummy that) {
             return this.data1 == that.data1 && this.data2 == that.data2;
         }
     }
}