JPA注解数据类型

 

import java.util.Date;



import javax.persistence.Basic;

import javax.persistence.Column;

import javax.persistence.Entity;

import javax.persistence.EnumType;

import javax.persistence.Enumerated;

import javax.persistence.FetchType;

import javax.persistence.GeneratedValue;

import javax.persistence.GenerationType;

import javax.persistence.Id;

import javax.persistence.Lob;

import javax.persistence.Table;

import javax.persistence.Temporal;

import javax.persistence.TemporalType;

import javax.persistence.Transient;



@Entity

@Table(name="person_jpa")

public class PersonJPA {

 private Integer id;     //主键，自增

 private String name;

 private Date birthday;  //日期类型

 private Gender gender = Gender.MAN; //枚举

 private byte[] image;   //存放很大的字节流

 private String info;    //存放很大的文件

 private String imgpath; //不想映射到数据库中的表字段

 

 public PersonJPA(){}

 public PersonJPA(String name){

  this.name=name;

 }

 

 //id为主键，策略为auto，它为默认值，也可以省略下面括号里面的内容

 @Id @GeneratedValue(strategy=GenerationType.AUTO)

 public Integer getId() {

  return id;

 }

 public void setId(Integer id) {

  this.id = id;

 }

 @Column(length=20,name="person_name",nullable=false)

 public String getName() {

  return name;

 }

 public void setName(String name) {

  this.name = name;

 }

 /**

  * 使用@Temporal注解，可以设置日期类型

  * @return

  */

 @Temporal(TemporalType.DATE) @Column(length=12)

 public Date getBirthday() {

  return birthday;

 }

 public void setBirthday(Date birthday) {

  this.birthday = birthday;

 }

 /**

  * @Enumerated表示枚举注解

  * @return

  */

 @Enumerated(EnumType.STRING) @Column(nullable=false,length=8)

 public Gender getGender() {

  return gender;

 }

 public void setGender(Gender gender) {

  this.gender = gender;

 }

 /**

  * 使用@Basic注解，表示当获取person对象时，并不会加载该属性的值。只有当需要获取它的值时且

  * EntityManager是打开的，那么只需要调用它的get方法就可以了。有点类似懒加载原理。

  * @return

  */

 @Lob @Basic(fetch=FetchType.LAZY)

 public byte[] getImage() {

  return image;

 }

 public void setImage(byte[] image) {

  this.image = image;

 }

 /**

  * 使用@Lob注解，表示设置大字符串，例如一片文章等

  * @return

  */

 @Lob

 public String getInfo() {

  return info;

 }

 public void setInfo(String info) {

  this.info = info;

 }

 /**

  * 使用@Transient注解，表示该字段并不会映射到数据库的表字段

  * @return

  */

 @Transient

 public String getImgpath() {

  return imgpath;

 }

 public void setImgpath(String imgpath) {

  this.imgpath = imgpath;

 }



}



public enum Gender {

 MAN,WOMAN



}