保存之前先檢測entity狀態(tài)

• 檢測id和version
• 實現Persistable接口
• 實現EntityInformation接口

網上大部分例子都是第一種檢測方式，即檢測id和version，下面舉個實現Persistable接口的例子：

@Setter
@Getter
@MappedSuperclass
@EntityListeners(AuditingEntityListener.class)
public class BaseBean implements Persistable<String> {
    
    @Transient
    private boolean isNew = true;

    @Id
    @GeneratedValue(generator = "uuid")
    @GenericGenerator(name = "uuid", strategy = "com.test.MyIdentifierGenerator")
    @Column(name = "id")
    private String id;

    @Version
    @Column(name = "version")
    private Integer version;

    @CreatedBy
    @Column(name = "created_user")
    private String createdUser;

    @CreatedDate
    @Column(name = "created_date")
    private Date createdDate;

    @LastModifiedBy
    @Column(name = "modified_user")
    private String modifiedUser;

    @LastModifiedDate
    @Column(name = "modified_Date")
    private Date modifiedDate;

    @Override
    public boolean isNew() {
        return this.isNew;
    }
    
    @PostLoad
    public void markNotNew() {
        this.isNew = false;
    }
}

PS：
個人覺得還是不要總是檢測id和version，因為那里面要涉及檢測邏輯，不如直接標識isNew來的快。