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Student.java

public class Student
{

    private String name;
    private int age;
    private Address address;

    public Student(String name, int age, Address address)
    {
        this.name = name;
        this.age = age;
        this.address = address;
    }

    public String getName()
    {
        return name;
    }

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

    public int getAge()
    {
        return age;
    }

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

    public Address getAddress()
    {
        return address;
    }

    public void setAddress(Address address)
    {
        this.address = address;
    }

}

public class Address
{

    private String country;
    private String city;

    public Address(String country, String city)
    {
        this.country = country;
        this.city = city;
    }

    public String getCountry()
    {
        return country;
    }

    public void setCountry(String country)
    {
        this.country = country;
    }

    public String getCity()
    {
        return city;
    }

    public void setCity(String city)
    {
        this.city = city;
    }

    public Student getStudentWithAddress(String name, int age)
    {
        /*
         * The this keyword can be passed as argument in the constructor call.
         * 
         * It is useful if we have to use one object in multiple classes.
         */
        Student student = new Student(name, age, this);
        return student;
    }
}

public class StudentTest
{

    public static void main(String[] args)
    {

        Address addressObject = new Address("India","Bangalore");
        Student student = addressObject.getStudentWithAddress("Peter", 27);
        System.out.println("Name : "+student.getName());
        System.out.println("Age  : "+student.getAge());

        System.out.println("Country : "+student.getAddress().getCountry());
        System.out.println("City    : "+student.getAddress().getCity());
    }

}