大数据字段映射与字段延迟加载
当持久化类的属性为大字段时，String类型映射到数据库中最大的长度为255，满足不了需求，应该通过@Lob注解标注在String类型属性的get方法上，表示映射到数据库中为大文本类型；@Lob注解也可用于Byte[]类型，映射到数据库中为存放二进制数据类型
package cn.com.jyp.model;import javax.persistence.Basic;import javax.persistence.Entity;import javax.persistence.FetchType;import javax.persistence.GeneratedValue;import javax.persistence.Id;import javax.persistence.Lob;import javax.persistence.Table;@Entity@Table(name = "person")public class Person {private Integer id;private String name;private String introduction;// 简介@Id@GeneratedValuepublic Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}@Lob@Basic(fetch = FetchType.LAZY)public String getIntroduction() {return introduction;}public void setIntroduction(String introduction) {this.introduction = introduction;}}