我目前正在编写一个服务，我可以用一些数据存储地理空间点。我有一个“dataPoint”类，如下所示：
@Entity
@Table(name = "datapoint")
public class DataPoint {
@Id
int dataPoint_id;
@Column(name = "body")
String body;
@Column(name = "location", columnDefinition = "Geometry")
PGgeometry location;
@Column(name = "deleted")
boolean deleted;
//Getters and Setters...
我正在尝试使用Spring Boot简单地通过API路径向PostGIS数据库添加包含一些信息的点。我已经构建了一个如下所示的控制器：
@RestController
@RequestMapping(value = "/dataPoint")
public class DataPointController {
@Autowired
private DataPointService myPointService;
@RequestMapping(value = "/add/{body}/{latitude}/{longitude}/")
public DataPoint addDataPoint(@PathVariable String body, @PathVariable double latitude, @PathVariable double longitude){
DataPoint myPoint = new DataPoint();
myPoint.setBody(body);
PGgeometry geometry = new PGgeometry();
try {
geometry.setValue("POINT("+longitude +" " + latitude+")");
geometry.setType("POINT");
// Debugging Stuff
System.out.println("GEOMETRY VALUE LOOK: {{{{ " + geometry.getValue() + " " + geometry.getType());
} catch (SQLException e) {
e.printStackTrace();
}
myPoint.setLocation(geometry);
myPointService.saveDataPoint(myPoint);
return myPoint;
}
又与DataPointService相关联，saveDataPoint()只是作为public void saveDataPoint(DataPoint myPoint) {
dataPointRepository.save(myPoint);
}
看起来像这样的控制器之间的中间人：
DataPointRepository和@Repository
public interface DataPointRepository extends JpaRepository<DataPoint, Integer> {
}
，如下所示：
Failed to write HTTP message: org.springframework.http.converter.HttpMessageNotWritableException: Could not write content: Direct self-reference leading to cycle (through reference chain: com.testing.model.DataPoint["location"]->org.postgis.PGgeometry["geometry"]->org.postgis.Point["firstPoint"]); nested exception is com.fasterxml.jackson.databind.JsonMappingException: Direct self-reference leading to cycle (through reference chain: com.testing.model.DataPoint["location"]->org.postgis.PGgeometry["geometry"]->org.postgis.Point["firstPoint"])
但是，当我访问我的添加链接时，我收到此错误：
@JsonBackReference我已经看到$('input[class="input-text"]').on('change', (event) => {
event.preventDefault();
$('#checkout').removeAttr('disabled');
});
...
<button type="submit" className="btn" id="checkout" disabled>Checkout</button>
及其在一些示例中使用的对偶，然而，它已用于实体来回链接的情况，我在这里看不到，实际上，错误甚至看起来都不是循环的，所以这里发生了什么？