Geotools wkt coordinate system conversion

Reference article ：
java geotools Coordinate transformation
Maven in GeoTools The introduction of - Maven Of repository And mirror The relationship between

background

 Use geotools  Yes WKT String for coordinate system conversion .

pom Package introduction

  <repositories>
      <repository>
        <id>osgeo</id>
        <name>OSGeo Release Repository</name>
        <url>https://repo.osgeo.org/repository/release/</url>
        <snapshots><enabled>false</enabled></snapshots>
        <releases><enabled>true</enabled></releases>
      </repository>
      <repository>
        <id>osgeo-snapshot</id>
        <name>OSGeo Snapshot Repository</name>
        <url>https://repo.osgeo.org/repository/snapshot/</url>
        <snapshots><enabled>true</enabled></snapshots>
        <releases><enabled>false</enabled></releases>
      </repository>
    </repositories>
    <!-- gt-epsg-hsql  This is epsgcode Of , Make sure to introduce , Otherwise, the coordinate system cannot be found -->
     <dependency>
            <groupId>org.geotools</groupId>
            <artifactId>gt-epsg-hsql</artifactId>
            <version>20.0</version>
        </dependency>
	<dependency>
         <groupId>org.geotools</groupId>
         <artifactId>gt-referencing</artifactId>
         <version>20.0</version>
     </dependency>
     <dependency>
         <groupId>org.geotools</groupId>
         <artifactId>gt-api</artifactId>
         <version>20.0</version>
     </dependency>

Code implementation

/** *  Single geom transformation  * geotools In the installation package of x,y The coordinates are reversed , therefore , Direct use geomtry transformation , The exported data is wrong , First general  * x,y Change the coordinates of . therefore , I choose to assemble geomtry. * @param geom * @return */
    public static Geometry geometryTransform2(Geometry geom, int sourceEPSGCode,int targetEPSGCode ){
    

        try{
    
            //CoordinateReferenceSystem There are two ways to generate ,EPSG and WKT, However , I found that the coordinate system I needed prj The contents of the file are used to convert the message “ non-existent .... What kind of ..”
            // So using EPSG, Even if EPSG, Of the exported converted projection file prj Still wrong ,arcgis  Can't recognize . Of course , In the same coordinate system prj  The contents of the file are the same , Just replace it with something else .
            CoordinateReferenceSystem crsresource = CRS.decode("EPSG:"+ epsgCode);
            CoordinateReferenceSystem crsTarget = CRS.decode("EPSG:"+ targetEPSGCode);
            //  Projection conversion 
            MathTransform transform = CRS.findMathTransform(crsresource, crsTarget,true);
            String wktString = geom.toString();
            log.debug(" Before conversion WKT character string ：" + wktString);
            // take WKTString Regular matching of coordinates in , After the projection conversion, the corresponding coordinates in the string are replaced 
            Pattern pattern = compile("[1-9]\\d*\\.?\\d*\\s[1-9]\\d*\\.?\\d*");
            Matcher matcher = pattern.matcher(wktString);
            while (matcher.find()){
    
                String cordStr = matcher.group();
                String[] cord = cordStr.split("\\s+");
                double x= Double.parseDouble(cord[0]);
                double y= Double.parseDouble(cord[1]);
                // Use coordinate when , Results dest Medium x The number of digits in the coordinates is a scientific count , So it is not recommended to use 
                /*Coordinate source = new Coordinate(y, x); Coordinate dest = new Coordinate(); JTS.transform(source,dest, transform); String[] str = dest.toString().substring(1, dest.toString().length() - 1).split(",");*/
                String point="POINT(" + y + " " + x + ")";
                Geometry pointGeom = reader.read(point);
                Geometry resGeom = JTS.transform(pointGeom, transform);
                String[] str = resGeom.toString().substring(resGeom.toString().lastIndexOf("(")+1, resGeom.toString().length() - 1).split("\\s+");
                String cordStr2 = str[1]+" "+str[0];
                wktString = wktString.replaceAll(cordStr,cordStr2);
            }
            log.debug(" Converted WKT character string ：" + wktString);
            Geometry read = reader.read(wktString);
            return read;
        } catch (Exception e) {
    
            log.debug(" Error in coordinate system conversion ：" + e.getMessage());
            return null;
        }
    }

test

public static void main(String[] args) {
    
	 String wktStr = "POLYGON((40535321.97750524 3276858.489317663,40534838.475054964 3276742.437636584,40534885.506722644 3276050.3168770154,40535410.02098725 3276621.3582205614,40535321.97750524 3276858.489317663))";
	 Geometry geometry = reader.read(wktStr);
     Geometry targetGeometry = WKTUtil.geometryTransform2(geometry,4528,4326);
     System.out.println(targetGeometry.toString());
}