Merging two objects in Java

Question

I have two objects of same type.

Class A {
  String a;
  List b;
  int c;
}

A obj1 = new A();
A obj2 = new A();

obj1 => {a = \"hello\"; b = null; c = 10         


        

Answer 1

Maybe something like

class A {
    String a;
    List<..> b;
    int c;

    public void merge(A other) {
        this.a = other.a == null ? this.a : other.a;
        this.b.addAll(other.b);
        this.c = other.c == 0 ? this.c : other.c;
    }
}

A a1 = new A();
A a2 = new A();

a1.a = "a prop";
a2.c = 34;

a1.merge(a2);

A.merge might return a new A object instead of modifing current.