實體基類：是否啟用

@MappedSuperclass
public abstract class AbstractBasis extends AbstractEntity
{
	private static final long serialVersionUID = 7952571906802309278L;
	
	/**
	 * 禁用狀態，false：禁用  true：可用
	 */
	private Boolean isEnable = true;
	
	@Column(nullable = false)
	public Boolean getIsEnable()
	{
		return isEnable;
	}
	public void setIsEnable(Boolean isEnable)
	{
		this.isEnable = isEnable;
	}
}
 

@MappedSuperclass 作用：封閉類中的通用屬性（如：id）,此類不能再新增@Entity或@Table註解，即不會對映到資料庫表,產生資料庫表，但該類的屬性將對映到其子類中，資料庫中表也將生成對應的欄位。

實體類（標籤）

@Entity
@Table(name = "edu_tag")
public class EduTag extends AbstractBasis {
	
	private static final long serialVersionUID = -5409801373006627913L;
	
	private String code;
	private Long appId;
	private Long corpCode;/**教育號編碼 */
	private String name;
	private School school;
	
	@Id
	@Column(name="edu_tag_code",nullable = false, length = 20)
	public String getCode() {
		return code;
	}
	public void setCode(String code) {
		this.code = code;
	}
	@Column(name="edu_tag_name",nullable = false,length = 20)
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	@Column(name="edu_tag_appId" ,nullable = false,length = 20)
	public Long getAppId() {
		return appId;
	}
	public void setAppId(Long appId) {
		this.appId = appId;
	}
	@Column(name="edu_tag_corpCode", nullable = false,length = 20)
	public Long getCorpCode() {
		return corpCode;
	}
	public void setCorpCode(Long corpCode) {
		this.corpCode = corpCode;
	}
 

	     @OneToOne(cascade = CascadeType.REFRESH , fetch = FetchType.EAGER)
	@JoinColumn(name = "edu_corp_shcool")
	public School getShcool() {
		return shcool;
	}
	public void setShcool(School shcool) {
		this.shcool = shcool;
	}
}

@Entity ： 實體類
@Table（name  = "xxx"）： 定義資料庫表名xxx

@Id ： 定義主鍵

@Column： 定時資料庫表字段 （name:欄位名，nullable:是否允許為null，length:欄位長度）

@OneToOne： 定時外來鍵（CascadeType.REFRESH：保持資料完整，查檢關聯表中的資料，FetchType.EAGER：急載入 ）

@JoinColumn： 功能與@Column類似。


org.springframework.http.converter.HttpMessageNotWritableException: Could not write content: could not initialize proxy - no Session (through reference chain: com.nenglong.zsedu.ucenter.api.po.educorp.EduCorp["organization"]->

com.nenglong.zsedu.ucenter.api.po.basic.Organization_$$_jvst2c4_12["name"]); nested exception is com.fasterxml.jackson.databind.JsonMappingException:

 could not initialize proxy - no Session (through reference chain: com.nenglong.zsedu.ucenter.api.po.educorp.EduCorp["organization"]->com.nenglong.zsedu.ucenter.api.po.basic.Organization_$$_jvst2c4_12["name"])

該報錯的解決方法： 將FetchType.EAGER.LZAY改為 FetchType.EAGER。