Cfrgtkky

I am getting polygon as a set of points. (text or JSON representation)

I need to do the following:

1) insert polygon to PostGIS using JDBC

2) I am getting an object coordinate ( point ) and I need to check if this point inside polygons or not.

I saw different examples but I didn't find any which is using JDBC ( Java ).

Can you please share the simple java snippet or pointing me to already an existing example.

Note polygon in my case is not a cycle

Thanks
Oleg.

1) You can use something like that

        String url = "jdbc:postgresql://localhost:5432/test";

        try (java.sql.Connection conn = DriverManager.getConnection(url, "user", "password")) {

            Class.forName("org.postgresql.Driver");

            GeometryFactory geometryFactory = new GeometryFactory(new PrecisionModel(), 4326);

            PackedCoordinateSequenceFactory csFactory = new PackedCoordinateSequenceFactory();

            CoordinateSequence sequence = csFactory.create(5, 2);

            sequence.setOrdinate(0 /*first point*/, 0, 92.63671875);

            sequence.setOrdinate(0 /*first point*/, 1, 56.88500172043518);

            sequence.setOrdinate(1, 0, 101.66748046874999);

            sequence.setOrdinate(1, 1, 56.88500172043518);

            sequence.setOrdinate(2, 0, 101.66748046874999);

            sequence.setOrdinate(2, 1, 59.80063426102869);

            sequence.setOrdinate(3, 0, 92.63671875);

            sequence.setOrdinate(3, 1, 59.80063426102869);

            sequence.setOrdinate(4 /*closed point*/, 0, 92.63671875);

            sequence.setOrdinate(4 /*closed point*/, 1, 56.88500172043518);

            // pass an array of Coordinate or a CoordinateSequence

            Polygon geo = geometryFactory.createPolygon(sequence);

            // you can use it to check if this point inside polygons

            // or you can use just query, something like that SELECT * FROM table_name WHERE st_contains(geom, your_point)

            boolean isContains = geo.contains(geometryFactory.createPoint(new Coordinate(99.404296875,

                                                                                                                                                                     58.60261057364717)));

            WKBWriter writer = new WKBWriter();

            PreparedStatement preparedStatement =

                            conn.prepareStatement("INSERT INTO table_name (geom) VALUES (ST_GeomFromWKB(?, 4326))");

            preparedStatement.setBytes(1, writer.write(geo));

            int rows = preparedStatement.executeUpdate();

            if (rows > 0) {

                System.out.println(" Successful insert! ");

            } else {

                System.out.println(" Failed insert!");

            }

            preparedStatement.close();

        } catch (Exception e) {

            e.printStackTrace();

        }

dependencies for that (pom.xml, use repository http://repo.boundlessgeo.com/main/): 



 `<dependencies>

            <dependency>

                <groupId>org.locationtech.jts</groupId>

                <artifactId>jts-core</artifactId>

                <version>1.16.0</version>

            </dependency>

            <dependency>

                <groupId>org.locationtech.jts</groupId>

                <artifactId>jts-modules</artifactId>

                <version>1.16.0</version>

                <type>pom</type>

            </dependency>

            <dependency>

                <groupId>org.geotools</groupId>

                <artifactId>gt-main</artifactId>

                <version>20.1</version>

            </dependency>

            <dependency>

                <groupId>org.geotools</groupId>

                <artifactId>gt-geojson</artifactId>

                <version>20.1</version>

            </dependency>

            <dependency>

                <groupId>org.geotools.jdbc</groupId>

                <artifactId>gt-jdbc-postgis</artifactId>

                <version>20.1</version>

                <scope>test</scope>

            </dependency>

            <dependency>

                <groupId>org.postgresql</groupId>

                <artifactId>postgresql</artifactId>

                <version>42.2.1</version>

                <scope>compile</scope>

            </dependency>

        </dependencies>`

2) You can use jts for that (as you can see above) or you can use Postgis query like that

    SELECT * FROM table_name

    WHERE st_contains(geom, st_setsrid(st_makepoint(99.404296875, 58.60261057364717), 4326))