analytics/informix/extend/spatial.8.22.FC2/examples/java/GeometryToWKT.java

/*
 * Title:       GeometryToWKT.java 1.00 2002/05/14
 *
 *      Licensed Materials - Property of IBM and/or HCL
 *      IBM Informix  Spatial DataBlade
 *      (c) Copyright IBM Corporation 2002 All rights reserved.
 *      (c) Copyright HCL Technologies Ltd. 2017.  All Rights Reserved.
 *
 *      US Government Users Restricted Rights - Use, duplication or
 *      disclosure restricted by GSA ADP Schedule Contract with
 *      IBM Corp.
 */
import java.sql.*;
import java.util.*;
import com.ibm.spatial.geom.Geometry;
import com.ibm.spatial.srs.CoordRefManager;
import com.ibm.spatial.SpatialException;
import com.ibm.spatial.io.IfxSQLData;

public class GeometryToWKT {

	static String url = null;
	Connection conn = null;
	Map typeMap = null;

	public GeometryToWKT() throws ClassNotFoundException {
   		// Loading driver
		System.out.print("Loading JDBC driver...");
		Class.forName("com.informix.jdbc.IfxDriver");
		System.out.println("ok");
	}

	public static void main(String[] args) {
		try {
			GeometryToWKT app = new GeometryToWKT();
			app.init(args);
			app.doRun();
			app.cleanup();
		} catch (Exception e) {
			System.out.println("ERROR: " + e.getMessage() + "\n");
			e.printStackTrace();
		}
    }

    void doRun() throws SQLException, SpatialException {
		/**
		 * Set up a CoordRefManager database connection. This connection
		 * will be used to retrieve spatial reference data associated
		 * with the geometries we're going to read.
		 */
		CoordRefManager.getInstance().setConnection(conn);

		/**
		 * Before retrieving geometry user-defined types, we have to
		 * associate a JDBC custom typemap to the current connection.
		 */
		System.out.println("Setting up typemap...");
		typeMap = IfxSQLData.enableTypes(conn);
		System.out.println("enableTypes...ok");
		System.out.println();

        // Run the query
        System.out.println("Displaying well-known text...");
		Statement stmt = conn.createStatement();
		ResultSet rs = stmt.executeQuery("SELECT id, geom FROM geom_t where id >= 0");
		while (rs.next()) {
			Integer id = (Integer)rs.getObject(1);
			Geometry geo = (Geometry) rs.getObject(2, typeMap);
			if (geo == null) {
				System.out.println("NULL");
				continue;
			}

			// Print out the well-known text representation
			System.out.println(geo.asText());
		}
		stmt.close();
	}

	// Creates the geometry table and inserts sample data.
    void init(String args[]) throws SQLException, SpatialException {

		if (args.length == 0) {
			if (url == null || url.length() == 0) {
				throw new RuntimeException(
					"Connection URL must be provided in " +
					"order to run this sample program!");
			}
		} else {
			url = args[0];
		}

   		// Getting connection
        System.out.print("Getting connection...");
        conn = DriverManager.getConnection(url);
        System.out.println("ok\n");

		// Setting up the custom typemap
		System.out.println("Setting up typemap...");
		typeMap = IfxSQLData.enableTypes(conn);
		System.out.println("enableTypes...ok");
		System.out.println();

        // Drop the test table
		PreparedStatement pstmt;
		try {
			pstmt = conn.prepareStatement("drop table geom_t");
            pstmt.executeUpdate();
        } catch (SQLException e) {
            // ignore error when the table does not exist
            System.out.println("Table does not exist");
        }

        // Creating a table and inserting data
        System.out.println("Creating table geom_t (id INT, geom ST_Geometry), " +
							"and inserting data ...");
        pstmt = conn.prepareStatement(
			"CREATE TABLE geom_t (id INT, geom ST_Geometry)");
        pstmt.executeUpdate();

        System.out.println("Inserting values...");
        pstmt = conn.prepareStatement(
			"INSERT INTO geom_t VALUES(0, NULL::ST_Geometry)");
        pstmt.executeUpdate();

        pstmt = conn.prepareStatement(
			"INSERT INTO geom_t VALUES(1, '0 point (-100.0 37.5)')");
        pstmt.executeUpdate();

        pstmt = conn.prepareStatement(
			"INSERT INTO geom_t VALUES(2, '0 polygon ((-100 37.5,-100 38.8,-99 39,-99 37.5,-100 37.5))')");
        pstmt.executeUpdate();
	}

    void cleanup() throws SQLException {
        // Drop the test table
		try {
            System.out.println("Dropping table geom_t ...");
			PreparedStatement pstmt = conn.prepareStatement("drop table geom_t");
            pstmt.executeUpdate();
        } catch (SQLException e) {
            // ignore error when the table does not exist
            System.out.println("Table does not exist");
        }

		// Closing connection
		System.out.print("Closing connection...");
		conn.close();
		System.out.println("ok");
	}
}