mybatis读写数据库 geometry类型数据

数据库字段类型 ：geometry

引入geo工具包 com.vividsolutions 版本1.13

方式1 ：使用mysql函数 ST_AsText: 可将mysql的geometry类型转换成 string类型， ST_GeometryFromText : 将wkt描述的字符串转换为 mysql中geometry类型， 这种方法简单直接，但需编写原生sql，不支持mybatis insert update之类的方法。

方式2 ：使用mybatis自定义类型转换器主要代码

<result column="coordinate"  property="coordinate" typeHandler="GeometryTypeHandler"/>

@TableField(typeHandler = GeometryTypeHandler.class)
	private String coordinate;

@MappedTypes({String.class})
@MappedJdbcTypes({JdbcType.OTHER})
public class GeometryTypeHandler extends BaseTypeHandler<String> {


	@Override
	public void setNonNullParameter(PreparedStatement preparedStatement, int i, String s, JdbcType jdbcType) throws SQLException {


			Geometry geo = null;
			try{
				//String转Geometry
				geo = new WKTReader(new GeometryFactory(new PrecisionModel())).read(s);
				// Geometry转WKB
				byte[] geometryBytes = new WKBWriter(2, ByteOrderValues.LITTLE_ENDIAN, false).write(geo);
				// 设置SRID为mysql默认的 0
				byte[] wkb = new byte[geometryBytes.length+4];
				wkb[0] = wkb[1] = wkb[2] = wkb[3] = 0;
				System.arraycopy(geometryBytes, 0, wkb, 4, geometryBytes.length);
				preparedStatement.setBytes(i,wkb);
			}catch (ParseException e){
				
			}
		}
	}

	@Override
	public String getNullableResult(ResultSet resultSet, String s){
		try(InputStream inputStream = resultSet.getBinaryStream(s)){
			Geometry geo = getGeometryFromInputStream(inputStream);
			if(geo != null){
				return geo.toString();
			}
		}catch(Exception e){
			
		}
		return null;
	}

	@Override
	public String getNullableResult(ResultSet resultSet, int i){
		try(InputStream inputStream = resultSet.getBinaryStream(i)){
			Geometry geo = getGeometryFromInputStream(inputStream);
			if(geo != null){
				return geo.toString();
			}
		}catch(Exception e){
			
		}
		return null;
	}

	@Override
	public String getNullableResult(CallableStatement callableStatement, int i) throws SQLException {
		return "";
	}
	/**
	 * 流 转 geometry
	 * */
	private  Geometry getGeometryFromInputStream(InputStream inputStream) throws Exception {

		Geometry dbGeometry = null;

		if (inputStream != null) {
			// 二进制流转成字节数组
			byte[] buffer = new byte[255];

			int bytesRead = 0;
			ByteArrayOutputStream baos = new ByteArrayOutputStream();
			while ((bytesRead = inputStream.read(buffer)) != -1) {
				baos.write(buffer, 0, bytesRead);
			}
			// 得到字节数组
			byte[] geometryAsBytes = baos.toByteArray();
			// 字节数组小于5 异常
			if (geometryAsBytes.length < 5) {
				throw new PlatformAlertException("坐标异常");
			}

			//字节数组前4个字节表示srid 去掉
			byte[] sridBytes = new byte[4];
			System.arraycopy(geometryAsBytes, 0, sridBytes, 0, 4);
			boolean bigEndian = (geometryAsBytes[4] == 0x00);
			// 解析srid
			int srid = 0;
			if (bigEndian) {
				for (int i = 0; i < sridBytes.length; i++) {
					srid = (srid << 8) + (sridBytes[i] & 0xff);
				}
			} else {
				for (int i = 0; i < sridBytes.length; i++) {
					srid += (sridBytes[i] & 0xff) << (8 * i);
				}
			}

			WKBReader wkbReader = new WKBReader();
			// WKBReader 把字节数组转成geometry对象。
			byte[] wkb = new byte[geometryAsBytes.length - 4];
			System.arraycopy(geometryAsBytes, 4, wkb, 0, wkb.length);
			dbGeometry = wkbReader.read(wkb);
			dbGeometry.setSRID(srid);
		}
		return dbGeometry;
	}
}