学习EJB的很好范例

				package com.wiley.compBooks.roman.entity.account;
				
				import java.io.Serializable;
				
				/**
				 * Primary Key class for Account.
				 */
				public class AccountPK implements java.io.Serializable {
				  public String accountID;
				
				  public AccountPK(String id) {
					this.accountID = id;
				  }
				
				  public AccountPK() {
				  }
				
				  public String toString() {
					return accountID;
				  }
				}