how reachs an object with getter setter from different package in java?

Question

public class Class1 {
    List<Class3> allData = new ArrayList<Class3>();

    public void setAllData(List<Class3> allData) {
        this.allData = allData;
    }

    public List<Class3> getAllData() {
        return allData;
    }
}

I have a class which name is Class2 in different package but in the same project with Class1 . How I reach to "allData" from Class1 to use in Class2 ? With getter and setter ? Or any alternative way ?

Answer 1

How I reach to "allData" from Class2? With getter and setter? Or any alternative way?

yes, you should use public getter/setter. The only alternative way is to use reflection (or make allData public, which is not recommended too - brokes encapsulation ).

Your allData field is package-private , so you can't directly reach it from class Class2 which is placed in another package

Answer 2

You can reach private fields with public getter and setter methods.

You have to make a public getter method in Class2. Then you can call that method in the other classes.

Answer 3

From the other class you first have to instantiate an Class1 object.

Class1 c1 = new Class1()

Then you can access allData using the getters and setters.

List<Class3> allData = c1.getAllData();

List<Class3> newAllData = new ArrayList<Class3>();
c1.setAllData(newAllData);