hibernate基于注解的联合主键映射

逃离我推掉我的手 2024-02-17 22:18 17阅读 0赞

#### 联合主键映射 ####

以飞机的航线和起始地、目的地为例。在此以起始地和目的地作为联合主键。  
**联合主键实体类**

//注意，作为联合主键的实体类必须实现Serializable接口
    public class AirPort implements Serializable{
        
        private static final long serialVersionUID = 1L;
        private String startPort;
        private String endPort;
        public AirPort() {
            super();
            // TODO Auto-generated constructor stub
        }
        @Column(length=10)
        public String getStartPort() {
            return startPort;
        }
        public void setStartPort(String startPort) {
            this.startPort = startPort;
        }
        @Column(length=10)
        public String getEndPort() {
            return endPort;
        }
        public void setEndPort(String endPort) {
            this.endPort = endPort;
        }
    }

**航线实体类**

public class AirLine {
        
    
        private AirPort airPort;
        private double length;
        private Date day;
        public AirLine() {
            super();
            // TODO Auto-generated constructor stub
        }
        @EmbeddedId//声明联合主键只需这个注解即可，联合主键具体的属性可以在AirPort类中说明
        public AirPort getAirPort() {
            return airPort;
        }
        public void setAirPort(AirPort airPort) {
            this.airPort = airPort;
        }
        @Column(scale=6,precision=2)
        public double getLength() {
            return length;
        }
        public void setLength(double length) {
            this.length = length;
        }
        @Temporal(TemporalType.DATE)
        public Date getDay() {
            return day;
        }
        public void setDay(Date day) {
            this.day = day;
        }
    }