hibernate基于注解的组件映射

╰+攻爆jí腚メ 2024-02-17 22:17 25阅读 0赞

#### 基于注解的组件映射 ####

在此以person和name为例：  
**Name实体类**

public class Name {
        
        private String firstName;
        private String lastName;
        //...省略构造方法和getter，setter方法
    }

**Person实体类**

@Entity//声明该类要在表中映射
    public class Person {
        
        private int id;
        private Name name;
        private Date birthday;
        //无参构造
        @Id          // 声明该属性是主键字段
        @GeneratedValue        //声明主键生成策略是自增长
        public int getId() {
            return id;
        }
        public void setId(int id) {
            this.id = id;
        }
        /*
            @Embedded:声明该属性组件映射,如果不需要更改name属性在表中字段的默认值，只写该注解即可，如果需要修改name属性在表中字段的默认值，则还需以下配置；
            column = @Column(name = "first_name", length = 10):将组件相应的属性修改为什么值;
             name = "firstName":对组件的那个属性进行修改
        */
        @Embedded
        @AttributeOverrides(value = {
                @AttributeOverride(column = @Column(name = "first_name", length = 10), name = "firstName"),
                @AttributeOverride(column = @Column(name = "last_name", length = 10), name = "lastName") })
        public Name getName() {
            return name;
        }
        public void setName(Name name) {
            this.name = name;
        }
        @Temporal(TemporalType.DATE)
        public Date getBirthday() {
            return birthday;
        }
        public void setBirthday(Date birthday) {
            this.birthday = birthday;
        }
    }