Java

public void displayCustomerDetails(Address address) {
		System.out.println("Displaying customer details \n***************************");
		System.out.println("Customer Id : " + customerId); //can also use this.customerid
		System.out.println("Customer Name : " + customerName); //can also use this.customerName
		System.out.println("Contact Number :"+ contactNumber);
		System.out.println("Customer Address : " +this.getAddress());  //Here I want to print old address:confused: 
		
System.out.println();
	}
	
	
	public void updateDetails(Address address) {            //Association
		System.out.println("Updating customer address...");
		this.setAddress(address);
		System.out.println("New Customer Address :"+ " "+this.getAddress() ); //Here i want to print new address:confused:
	}

public class Customer {
	private String customerId;
	private String customerName;
	private long contactNumber;
	private Address address;        //Aggregation
	public Customer(String customerId, String customerName, long contactNumber, Address address) {   // Constructors and other methods
		this.customerId = customerId;
		this.customerName = customerName;
		this.contactNumber = contactNumber;                            
		this.address = address;
	}
	public String getCustomerId() {
		return customerId;
	}
	public String getCustonerId() {
		return customerId;
	}
	public String getCustomerName() {
		return customerName;
	}
	public void setCustomerName(String customerName) {
		this.customerName = customerName;
	}
	public long getContactNumber() {
		return contactNumber;
	}
	public void setContactNumber(long contactNumber) {
		this.contactNumber = contactNumber;
	}
	public Address getAddress() {
		return address;
	}
	public void setAddress(Address address) {
		this.address = address;
	}
	
	public void displayCustomerDetails(Address address) {
		System.out.println("Displaying customer details \n***************************");
		System.out.println("Customer Id : " + customerId); //can also use this.customerid
		System.out.println("Customer Name : " + customerName); //can also use this.customerName
		System.out.println("Contact Number :"+ contactNumber);
		System.out.println("Customer Address : " +this.getAddress());
		System.out.println();
	}
	
	public void updateDetails(long mobile) {
		System.out.println("Updating customer contact number...");
		this.setContactNumber(mobile);
		System.out.println("New Contact Number:"+ " "+this.getContactNumber());
	}
	public void updateDetails(Address address) {            //Association
		System.out.println("Updating customer address...");
		this.setAddress(address);
		System.out.println("New Customer Address :"+ " "+this.getAddress() );
	}
}

public class Address {
public String homeNo;
private String street;
private  String city;
private int pin;

public Address(String homeNo, String street, String city, int pin) {

	this.homeNo = homeNo;
	this.street = street;
	this.city = city;
	this.pin = pin;
}



public String getHomeNo() {
	return homeNo;
}



public String getStreet() {
	return street;
}


public String getCity() {
	return city;
}


public int getPin() {
	return pin;
}

}

public class Tester {
	public static void main(String[] args) {
		Address custAddress = new Address("D109", "Castle Street", "London", 65436);
		
		Customer customer = new Customer("C1016", "Stephen Abram", 7856341287L,custAddress);
		
		customer.displayCustomerDetails(custAddress );
		Address newAddress = new Address("D119"," St. Louis Street", "Springfield", 62729);	
		
		
		Long newContact = 7890098656L;
		
		
		
		customer.updateDetails(newContact); //calls the updateDetails(long mobile) - based on the parameter
        customer.updateDetails(newAddress); //calls the updateDetails(Address address) - based on the parameter	
       
}
}

Displaying customer details 
***************************
Customer Id : C1016
Customer Name : Stephen Abram
Contact Number :7856341287
Customer Address : Demo1.Address@123a439b    // see here it is not printing actual old address:confused:

Updating customer contact number...
New Contact Number: 7890098656
Updating customer address...
New Customer Address : Demo1.Address@7de26db8   // see it is not printing new address :confused: