Why serialVersionUID Is Required??
       serialVersionUID is used to identify the class during deserialization process.if you don't mention serialVersionUID in your class then  by default JVM will generate it .     JVM generated  serialVersionUID will be a 64 bit hash value of class name ,method and fields.But there is a problem in not declaring serialVersionUID manually.   Let me explain it with the example ,               This is my class which i want to serialize     public class Employee implements Serializable {           /**      *      */     public int getEmpId() {          return empId;     }     public void setEmpId(int empId) {         this.empId = empId;     }     public String getEmpName() {         return empName;     }   ...