我有一个@Entity类,需要对各个字段应用注释.我已经在下面的代码中列出了他们可以去的三个地方.

我应该把它们应用到场地本身,吸气剂还是吸气器？这三个选项之间的语义差异(如果有的话)是甚么.

import javax.persistence.Entity;
import javax.persistence.Table;
import javax.persistence.Id;

@Entity
@Table(name = "song")
public class Song { 
    // Annotations should only be applied to one of the below

    @Id 
    @Column(name="id",unique=true,nullable=false)
    private int    id;

    @Id
    @Column(name="id",nullable=false)
    public int getId() {
        return id;
    }

    @Id
    @Column(name="id",nullable=false)
    public void setId(int id) {
        this.id = id;
    }
}