实体类注解生成数据库表

实体基类：是否启用

@MappedSuperclass
public abstract class AbstractBasis extends AbstractEntity
{
	private static final long serialVersionUID = 7952571906802309278L;
	
	/**
	 * 禁用状态，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：封闭类中的通用属性（如：id）,此类不能再添加@Entity或@Table注解，即不会映射到数据库表,产生数据库表，但该类的属性将映射到其子类中，数据库中表也将生成对应的字段。

实体类（标签）

@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;/**教育号编码 */
	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 ： 实体类
@Table（name  = "xxx"）： 定义数据库表名xxx

@Id ： 定义主键

@Column： 定时数据库表字段 （name:字段名，nullable:是否允许为null，length:字段长度）

@OneToOne： 定时外键（CascadeType.REFRESH：保持数据完整，查检关联表中的数据，FetchType.EAGER：急加载 ）

@JoinColumn： 功能与@Column类似。


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"])

该报错的解决方法： 将FetchType.EAGER.LZAY改为 FetchType.EAGER。