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

I am using Spring Framework. I was facing the same issue on a project.
To solve it i used the class BeanUtils and the above method,

public static void copyProperties(Object source, Object target)

This is an example,

public class Model1 {
    private String propertyA;
    private String propertyB;

    public Model1() {
        this.propertyA = "";
        this.propertyB = "";
    }

    public String getPropertyA() {
        return this.propertyA;
    }

    public void setPropertyA(String propertyA) {
        this.propertyA = propertyA;
    }

    public String getPropertyB() {
        return this.propertyB;
    }

    public void setPropertyB(String propertyB) {
        this.propertyB = propertyB;
    }
}

public class Model2 {
    private String propertyA;

    public Model2() {
        this.propertyA = "";
    }

    public String getPropertyA() {
        return this.propertyA;
    }

    public void setPropertyA(String propertyA) {
        this.propertyA = propertyA;
    }
}

public class JustATest {

    public void makeATest() {
        // Initalize one model per class.
        Model1 model1 = new Model1();
        model1.setPropertyA("1a");
        model1.setPropertyB("1b");

        Model2 model2 = new Model2();
        model2.setPropertyA("2a");

        // Merge properties using BeanUtils class.
        BeanUtils.copyProperties(model2, model1);

        // The output.
        System.out.println("Model1.propertyA:" + model1.getPropertyA(); //=> 2a
        System.out.println("Model1.propertyB:" + model1.getPropertyB(); //=> 1b
    }
}