Hey Marty,
Glad you are contacting us, kind of wish you did so earlier (incase you are
looking at a race condition or something.). I did change the map/layer data
structure a few years back.
But still it looks like you are using things wrong... You are creating
one connection from your controller, and then a connection pool (maybe 10
connections) for each layer.
1. Create a single datastore - and keep it for use for each layer you want
to publish.
2. Use feature source to figure out the count (if you want to skip empty
layers)
3. Create a Map/Layer for the map you are trying to draw, reuse it multiple
times if you can (say for different bounding boxes)
4. be sure to dispose layers that are not in use
5. be sure to dispose stores that are no longer in use (this returns the
connections in their connection pool).
If PLANNER.getController(). getConnection() has a connection pool (why
wouldn't it) - consider setting up the DataStore using that connection pool
to avoid burning through your connections.
A lot of this is covered in the tutorials, please read through the
tutorials and let me and the user-list know if you have question.
As for your exception - here is LoopPipe.java
<http://www.docjar.com/html/api/sun/java2d/pipe/LoopPipe.java.html>
191 sg2d.loops.drawPathLoop.DrawPath(sg2d,
sg2d.getSurfaceData(),
192 transX, transY, p2df);
So your options for a NPE are:
- sg2d
- sg2d.loops
sg2d is used a bit further up the method, so sg2d.loops must be null. Work
back up the call chain trying to see how that could be null.
Or if you want to cut to the chase assume your geometry might be invalid or
otherwise harmed (since we are drawing a path and the path is determined by
the shape of the geometry). So try checking the geometry in the table that
is causing you trouble...
--
Jody Garnett
On 19 February 2016 at 12:58, Marty O'Neill II <[email protected]>
wrote:
> We have been using GeoTools to render maps in a software project we
> have been working on for over five years. However, there is one
> problem that has plagued us since day 1, and I'm wondering if anyone
> on the list has any suggestions.
>
> We are currently using GeoTools 12.0, but the problems we are
> experiencing have been around throughout the various versions for over
> five years. However, as our project continues, the scale of the
> regions we are examining is increasing, and the problem is becoming
> more frequent.
>
> The spatial data we are rendering using GeoTools is stored on a
> PostGIS-enabled Postgres DB. The software client we have been writing
> connects directly to the DB to read the layers.
>
> The size of the data we are using isn't tremendous, but it isn't
> exactly small, either. We often ask GeoTools to render maps drawn from
> layers rendered from 100s of MB of spatial data from the DB. For
> example, we may want to draw the entire state of Texas at the Block
> Group Level along with OSM roads for the entire state and a few other
> layers.
>
> We get a Null Pointer Exception message intermittently when we add
> layers or when we toggle layers on and off using the user interface.
> One way to trigger the problem is by loading a large dataset and
> quickly toggling a layer on and off.
>
> The Exception seems to happen more often when the size of the layers
> we are viewing in GeoTools are larger and/or when the network latency
> is higher.
>
> When we zoom into an area of the map which is outside of the extent of
> all of the layers (so that nothing is being rendered in the display)
> before we add new layers, the Exception seems to be less likely.
>
> If we add multiple layers quickly, one after another, the problem
> seems to be more likely.
>
> When we toggle off most or all of the layers before adding new layers,
> the Exception seems to be less likely.
>
> When the latency between the DB and the client is lower, the Exception
> seems to be less likely. For instance, if we are accessing the DB
> across the internet, it seems to be more likely than if we are
> accessing it across the LAN. Further, it seems to be more likely
> across the LAN than if we are accessing a DB on localhost.
>
> Following occurrence of this exception, our program still runs, but
> the GeoTools object stops rendering maps. Sometimes the map area
> becomes all white. Other times, it takes on a fill of one of a color
> from one of the line layers. If it takes on this fill, as soon
> as a layer is toggled or the extent is changed, the map area becomes
> all white, and nothing is rendered.
>
> I have included the Exception Message and the code we are using the
> create the layers below.
>
>
> Please let me know if you have any ideas about how to solve this
> problem and what other information you may need.
>
>
> Thank you,
>
> Marty
>
>
> Exception Message:
>
> 2016-02-12T16:26:07.055-0600 SEVERE null
> java.lang.NullPointerException
> at sun.java2d.pipe.LoopPipe.draw(LoopPipe.java:191)
> at
> sun.java2d.pipe.PixelToParallelogramConverter.draw(PixelToParallelogramConverter.java:148)
> at sun.java2d.SunGraphics2D.draw(SunGraphics2D.java:2438)
> at
> org.geotools.renderer.lite.StyledShapePainter.paint(StyledShapePainter.java:316)
> at
> org.geotools.renderer.lite.StreamingRenderer$PaintShapeRequest.execute(StreamingRenderer.java:3264)
> at
> org.geotools.renderer.lite.StreamingRenderer$PainterThread.run(StreamingRenderer.java:3525)
> at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
> at java.util.concurrent.FutureTask.run(FutureTask.java:262)
> at
> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
> at
> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
> at java.lang.Thread.run(Thread.java:745)
>
>
>
> This is how we are creating the layers:
>
> public Layer createLayer(String tableName, Style style, String name) {
> Layer layer = null;
>
> try {
> //the vacuum analyze removes the st_estimated_extent
> error. good riddance.
> Connection myconn = PLANNER.getController().getConnection();
> String query = "VACUUM ANALYZE " + UserState.userId + "."
> + tableName + ";";
> Statement stmt = myconn.createStatement();
> stmt.executeUpdate(query);
> Statement my_new_statement = myconn.createStatement();
> String check_rows = "SELECT COUNT(*) as my_int FROM " +
> UserState.userId + "." + tableName + ";";
> ResultSet my_results =
> my_new_statement.executeQuery(check_rows);
> long my_int = 0;
> while (my_results.next()) {
> my_int = my_results.getInt("my_int");
> }
>
> if (my_int == 0) {
> //if 0 was returned that means the table is empty.
> Don't create an empty layer.
> return null;
> }
>
> Map params = PLANNER.getController().getPostGIS();
> params.remove("schema");
> params.remove("role");
> params.put("schema", UserState.userId);
> params.put("role", UserState.userId);
>
> DataStore pgDatastore
> = DataStoreFinder.getDataStore(params);
>
> FeatureSource fs = pgDatastore.getFeatureSource(tableName);
> layer = new FeatureLayer(fs, style, name);
> if (layer == null) {
> System.out.println("Could not find stuff in database
> to create layer.");
> }
> map.layers().add(layer);
>
> } catch (IOException ex) {
> Logger.getLogger(ScenarioPanel.class.getName()).
> log(Level.SEVERE, null, ex);
> } catch (Exception e) {
> System.out.println("This is probably: ERROR:
> LWGEOM_estimated_extent: couldn't locate table within current schema
> \n");
> }
>
> return layer;
> }
>
>
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