编写实体如下

package demo.entity;

import java.util.UUID;

public class Product 
{
	private String id="";
	private String name="";
	private float price=0;
	private String madeIn="";
	
	public String getId() 
	{
		if ((id==null)||("".equals(id))||("null".equalsIgnoreCase(id))) {
			id=UUID.randomUUID().toString();
		}
		return id;
	}
	
        // 其他getter/setter
}

建表sql如下

create table PRODUCT(
id varchar(50) primary key not null,
name varchar(120) ,
price float,
madeIn varchar(120) 
);