How to iterate through all properties of a Java bean

Below is my bean structure. Employee.java is the parent bean. I would like to iterate through all the properties till the Zip.java and manipulate the values.

Could someone let me know how to do this in java.

**Employee.java**

private String id;
private String name;
private int age;
private Address addr;
private Contact cont;

**Address.java**

private String addr1;
private String addr2;
private String city;
private Zip zip;

**Contact.java**

private String phone;
private String email;

**Zip.java**

private String zipCd;
private String zipExt;