Question

I have this problem: I can write to a Postgis table with a geography type column and the data is entered correctly. When I try to get it back, I get a java.lang.IllegalArgumentException: Can’t convert object of type org.postgresql.util.PGobject

I’m using Hibernate Spatial 4.0M1, Postgis 2.0.2, Postgresql 9.1.7 and Spring 3.2, Postgis-jdbc 2.0.2 and I tried also 1.5.2 and Postgresql-jdbc 9.1-901.

This is the relevant part of my class

public class Poi {
@Id
@GeneratedValue(generator="t_pois_poisid_seq")
private long poisid;
@Column(name="name")
private String name;
@Column(name="userid")
private int owner;
//@Column(columnDefinition = "Geometry", name="location")
@Type(type="org.hibernate.spatial.GeometryType")
private Point location;


public Poi(){}

public Poi(String name, int owner, String wktPoint){
    this.name = name;
    this.owner = owner;
    WKTReader fromText = new WKTReader();
    Geometry geom = null;
    try{
        geom = fromText.read(wktPoint);
    }catch(ParseException e){
        throw new RuntimeException("Not a WKT string:" + wktPoint);
    }
    if (!geom.getGeometryType().equals("Point")) {
        throw new RuntimeException("Geometry must be a point. Got a " +  geom.getGeometryType());
    }
    //geom.setSRID(4326);
    this.location = (Point) geom;

}

}

And this is the error I get

java.lang.IllegalArgumentException: Can’t convert object of type org.postgresql.util.PGobject
org.hibernate.spatial.dialect.postgis.PGGeometryValueExtractor.toJTS(PGGeometryValueExtractor.java:99)
org.hibernate.spatial.dialect.AbstractJTSGeometryValueExtractor.extract(AbstractJTSGeometryValueExtractor.java:42)
org.hibernate.spatial.dialect.AbstractJTSGeometryValueExtractor.extract(AbstractJTSGeometryValueExtractor.java:37)
org.hibernate.type.AbstractStandardBasicType.nullSafeGet(AbstractStandardBasicType.java:269)
org.hibernate.type.AbstractStandardBasicType.nullSafeGet(AbstractStandardBasicType.java:265)
org.hibernate.type.AbstractStandardBasicType.nullSafeGet(AbstractStandardBasicType.java:238)
org.hibernate.type.AbstractStandardBasicType.hydrate(AbstractStandardBasicType.java:357)
org.hibernate.persister.entity.AbstractEntityPersister.hydrate(AbstractEntityPersister.java:2807)
org.hibernate.loader.Loader.loadFromResultSet(Loader.java:1545)
org.hibernate.loader.Loader.instanceNotYetLoaded(Loader.java:1477)
org.hibernate.loader.Loader.getRow(Loader.java:1377)
org.hibernate.loader.Loader.getRowFromResultSet(Loader.java:644)
org.hibernate.loader.Loader.doQuery(Loader.java:854)
org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:293)
org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:263)
org.hibernate.loader.Loader.loadEntity(Loader.java:1977)
org.hibernate.loader.entity.AbstractEntityLoader.load(AbstractEntityLoader.java:82)
org.hibernate.loader.entity.AbstractEntityLoader.load(AbstractEntityLoader.java:72)
org.hibernate.persister.entity.AbstractEntityPersister.load(AbstractEntityPersister.java:3821)
org.hibernate.event.internal.DefaultLoadEventListener.loadFromDatasource(DefaultLoadEventListener.java:458)
org.hibernate.event.internal.DefaultLoadEventListener.doLoad(DefaultLoadEventListener.java:427)
org.hibernate.event.internal.DefaultLoadEventListener.load(DefaultLoadEventListener.java:204)
org.hibernate.event.internal.DefaultLoadEventListener.proxyOrLoad(DefaultLoadEventListener.java:260)
org.hibernate.event.internal.DefaultLoadEventListener.onLoad(DefaultLoadEventListener.java:148)
org.hibernate.internal.SessionImpl.fireLoad(SessionImpl.java:1075)
org.hibernate.internal.SessionImpl.access$2000(SessionImpl.java:175)
org.hibernate.internal.SessionImpl$IdentifierLoadAccessImpl.load(SessionImpl.java:2421)
org.hibernate.internal.SessionImpl.get(SessionImpl.java:971)
com.prismio.pois.api.repository.HibernatePoiRepository.findOne(HibernatePoiRepository.java:30)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:601)
org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317)
org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:183)
org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:110)
org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204)
$Proxy24.findOne(Unknown Source)
com.prismio.pois.api.controller.PoiController.getUser(PoiController.java:40)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:601)
org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:219)
org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132)
org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:746)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:687)
org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:80)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:925)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:856)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:915)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:811)
javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:796)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)

Answer 1

If anyone is interested: the problem is that PostGIS returns a PGObject from a column type Geography and not PGGeometry, so the cast to PGgeometry is not possible. The solution I found using jdbcTemplate (and not Hibernate) is to cast the field from the resultset to PGObject and then create a PGGeometry like this:

PGgeometry geo = new PGgeometry(myPGObject.getValue());

Doing this, geo.getValue() returns a string in the form SRID=4326;POINT(40.70686417491799 -74.01572942733765) which is what I wanted. I could do the query using ST_AsText but it loses precision. I don’t know Hibernate well enough to propose a solution to this, but this is enough for my use case.