Is it possile to cast two different class but having the same attributes?

Question

I have two classes. ClassA and CLassB, they don't have any relation but they both have the same attributes. Is it possible to cast them or I have to set the attributes one by one?

Answer 1

The only way to "cast" them universally is using the reflection like this:

public static void copyObject(Object src, Object dest)
        throws IllegalArgumentException, IllegalAccessException,
        NoSuchFieldException, SecurityException {
    for (Field field : src.getClass().getFields()) {
        dest.getClass().getField(field.getName()).set(dest, field.get(src));
    }
}

Example:

static class ClassA {
    public int a;
    public String b;
    public double c;
}

static class ClassB {
    public int a;
    public String b;
    public double c;
}

public static void main(String[] args) throws Exception {
    ClassA a = new ClassA();
    a.a = 1;
    a.b = "test";
    a.c = 3.14;

    ClassB b = new ClassB();
    copyObject(a, b);
    System.out.println(b.a+", "+b.b+", "+b.c); // prints "1, test, 3.14"
}

However, as you may guess, that's not very good way to do things in Java.

Answer 2

You can create an Interface that gets implemented by both classes to set the attributes.

That way instead of casting you reference them by the interface

Example

public interface PersonalInfo {

    public void setName(String name);
    public void setAge(int age);

}

Then your implementations

public class ClassA implements PersonalInfo {


String name;
int age;

//other things and methods
@Override
public void setName(String name) {
    this.name = name;
}

@Override
public void setAge(int age) {
    this.age = age;
}

}

And for ClassB

public class ClassB implements PersonalInfo {

String name;
int age;

//other things and methods

@Override
public void setName(String name) {
    this.name = name;
}

@Override
public void setAge(int age) {
    this.age = age;
}

}