JPA和Mysql的Geometry类型结合使用

项目中需要存储地理范围类型（矩形区域），并能够按照区域范围进行检索，使用了Mysql数据库中的Geometry类型(Polygon)。
参考的几篇文章如下：
MySQL空间索引简单使用
mysql中的空间地理字段
让你的spring data jpa支持mysql的空间存储
springboot使用jpa绑定mysql空间数据geometry到实体类
总结几点：
1.实体类

@Data
@Entity
@Table(name = "cpxx_geoarea")
public class CpxxGeo {
    @Id
    @GenericGenerator(name = "product-uuid",strategy = "uuid")
    @GeneratedValue(generator = "product-uuid")
    @Column(name = "productId", columnDefinition = "varchar(100)")
    private String productId;                     //产品标识
    @Column(columnDefinition = "varchar(200)")
    private String productName;                    //产品名称
    @Column(columnDefinition = "Polygon COMMENT'矩形区域范围'")    
    private Polygon recArea;
    
    @Transient
    private Float topLeftLat;          //左上纬度
    @Transient
    private Float topLeftLon;          //左上经度

   @Transient
   private Float topRightLat;         //右上纬度
   @Transient
   private Float topRightLon;          //右上经度

   @Transient
   private Float lowerRightLat;          //右下纬度
   @Transient
   private Float lowerRightLon;          //右下经度

   @Transient
   private Float lowerLeftLat;         //左下纬度
   @Transient
   private Float lowerLeftLon;          //左下经度
   /**
   *
   */
   public void setRecArea(){
       String polygonStr = "Polygon((" +
            this.getLowerLeftLon() + " " + this.getLowerLeftLat() + "," +
            this.getLowerRightLon() + " " + this.getLowerRightLat() + "," +
            this.getTopRightLon() + " " + this.getTopRightLat() + "," +
            this.getTopLeftLon() + " " + this.getTopLeftLat() + "," +
            this.getLowerLeftLon() + " " + this.getLowerLeftLat()
            +"))";
      this.setRecArea(polygonStr);
  }

  /**
  *
  * @param polygonStr 矩形区域字符串
  */
  public void setRecArea(String polygonStr){
      WKTReader reader = new WKTReader();
      Geometry geom = null;
      try {
          geom = reader.read(polygonStr);
          this.recArea = (com.vividsolutions.jts.geom.Polygon) geom;
          this.recArea.setSRID(4326);
      }catch (Exception e){
          e.printStackTrace();
  }
}

2. Repository

public interface CpxxGeoRep extends JpaRepository<CpyxxGeo, String>{
	/**
	 * 区域范围检索
	 * @param polygon 矩形区域string：如Polygon((0 0， 10 0， 10 10， 0 10， 0 0));
	 * @return
	 */
    @Query(value = "select * from cpxx_geoarea where mbrcontains(?1, recArea)", nativeQuery = true)
    public List<CpxxGeo> findByAreaPolygon(Polygon polygon);
}

3.application.properties配置文件
这里一定要注意，需要配置方言为mysql方言。如下所示，其中hibernate.dialect即为方言配置。
如果方言未设置，会提示异常：Cannot get geometry object from data you send to the GEOMETRY field

spring:
  #jdbc config
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/gfg?serverTimezone=CTT&characterEncoding=utf-8&useSSL=false&allowPublicKeyRetrieval=true
    username: root
    password: 123456
  #jpa config
  jpa:
    show-sql: true
    hibernate:
      ddl-auto: update
      naming:
        physical-strategy: org.hibernate.boot.model.naming.PhysicalNamingStrategyStandardImpl
    properties:
      hibernate.dialect: org.hibernate.spatial.dialect.mysql.MySQL56InnoDBSpatialDialect

4.插入Geometry类型的数据

Insert into table(geo) values(st_geomfromtext(‘Polygon((0 0, 10 0, 10 10, 0 10, 0 0))’, 4326));

5.查询区域是否包含

MBRContains(geom1, geom2)   //判断geom1是否包含geom2
MBRWithin(geom1, geom2)     //判断geom2是否包含geom1

6.在geometry列上建立索引

Create spatial index sp_index on table(geo);

需要注意的是，只建立索引是不够的，同时要指定SRID（mysql默认srid为0），如上面代码中的this.recArea.setSRID(4326)即为指定84坐标系。如果不设置SRID，无法命中索引。