使用java geotools进行坐标转换

java geotools支持不同的坐标系之间进行转换，只需要转换的时候指定坐标系即可。

pom依赖文件如下：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" 
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>cr.cdrb</groupId>
    <artifactId>geo1</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
        <geotools.version>20.0</geotools.version>
    </properties>
    <repositories>
       <!-- <repository>
            <id>boundless</id>
            <name>boundless</name>
            <url>https://repo.boundlessgeo.com/main/</url>
        </repository>-->
<!--指定org.geotools的仓库地址-->
        <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>
    </repositories>
    <dependencies>
<!--指定org.geotools jar包依赖-->
        <dependency>
            <groupId>org.geotools</groupId>
            <artifactId>gt-api</artifactId>
            <version>${geotools.version}</version>
            <exclusions>
                <exclusion>
                    <groupId>javax.media</groupId>
                    <artifactId>jai_core</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>jgridshift</groupId>
                    <artifactId>jgridshift</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>commons-pool</groupId>
                    <artifactId>commons-pool</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>net.sf.geographiclib</groupId>
                    <artifactId>GeographicLib-Java</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
<!--指定坐标系查询数据库  代码中指定的坐标系会从这里查询，只支持其中有的坐标系-->
        <dependency>
            <groupId>org.geotools</groupId>
            <artifactId>gt-epsg-hsql</artifactId>
            <version>${geotools.version}</version>
        </dependency>
    </dependencies>
</project>

如果依赖下不下来，也可以去仓库自行下载，地址：Nexus Repository Manager

JAVA代码：

package geo1;

import org.locationtech.jts.geom.Coordinate;
import org.geotools.geometry.jts.JTS;

import org.geotools.referencing.CRS;

import org.opengis.referencing.FactoryException;
import org.opengis.referencing.crs.CoordinateReferenceSystem;
import org.opengis.referencing.operation.MathTransform;

import java.math.BigDecimal;
import java.text.DecimalFormat;

public class MyGeotools {
    public static void main(String[] args) {
        //某点的度分秒格式的经纬度，如果经纬度本身就是double格式的，就不需要再行计算
        Double y = Double.parseDouble(getPosition("32°11′38.977458″"));//纬度
        Double x = Double.parseDouble(getPosition("119°31′06.853758″"));//经度
        Double[] coordinate = getCoordinate(x, y);
        System.out.println("Y："+coordinate[0] + " " + "X："+coordinate[1]);

    }

    //坐标转换
    public static Double[] getCoordinate(Double x, Double y) {
        Double[] res = new Double[2];
        Coordinate tar = null;
        try {
            //封装点，这个是通用的，也可以用POINT（y,x）
            // private static WKTReader reader = new WKTReader( geometryFactory );
            Coordinate sour = new Coordinate(y, x);
            //这里要选择转换的坐标系是可以随意更换的
            CoordinateReferenceSystem source = CRS.decode("EPSG:4326");
            CoordinateReferenceSystem target = CRS.decode("EPSG:4549");
            //建立转换，下面两个我屏掉的转换方式会报出需要3/7参数的异常
            // MathTransform mathTransform = CRS.findMathTransform(source, target);
            //MathTransform mathTransform1 = CRS.findMathTransform(source, target, false);
            MathTransform transform = CRS.findMathTransform(source, target, true);
            tar = new Coordinate();
            //转换
            JTS.transform(sour, tar, transform);
        } catch (FactoryException | org.opengis.referencing.operation.TransformException e) {
            e.printStackTrace();
        }
        String[] split = (tar.toString().substring(1, tar.toString().length() - 1)).split(",");
        //经纬度精度
        DecimalFormat fm = new DecimalFormat("0.0000000");
        res[0] = Double.valueOf(fm.format(Double.valueOf(split[0])));
        res[1] = Double.valueOf(fm.format(Double.valueOf(split[1])));
        return res;
    }

    private static String getPosition(String position){
        String[] degree = position.split("\\°");
        if(degree.length == 1){
            return position;
        }
        String d = degree[0];
        String[] one = degree[1].split("\\′");
        String a = one[0];
        if(!a.contains(".")){
            if(a.substring(0,1).equals("0")){
                a = a.substring(1);
            }
        }else if(a.contains(".") && a.split("\\.").length > 1){
            a = a.substring(1);
        }
        String[] two = one[1].split("\\″");
        String b= two[0];
        if(!b.contains(".")){
            if(b.substring(0,1).equals("0")){
                b = b.substring(1);
            }
        }else if(b.contains(".") && b.split("\\.").length > 1){
            if(b.substring(0,1).equals("0")){
                b = b.substring(1);
            }
        }
        BigDecimal fen = new BigDecimal(a);
        BigDecimal miao = new BigDecimal(b);
        BigDecimal du = new BigDecimal(d);
//		float f = Float.valueOf(a)+ Float.valueOf(Float.valueOf(b)/60);
//		float du = Float.valueOf(f/60)+Float.valueOf(d);
        BigDecimal add = fen.add(miao.divide(new BigDecimal("60"),6, BigDecimal.ROUND_HALF_UP)).divide(new BigDecimal("60"),6, BigDecimal.ROUND_HALF_UP).add(du);
        return String.valueOf(add);
    }
}

结果如图：

注意，如果运行的时候报错如下：

No code "EPSG:4326" from authority "EPSG" found for object of type "EngineeringCRS".

那就是查找坐标系的数据库依赖没有引入，引入就可以了:

 <dependency>
            <groupId>org.geotools</groupId>
            <artifactId>gt-epsg-hsql</artifactId>
            <version>${geotools.version}</version>
        </dependency>

 参考文档：

java geotools 坐标转换_不知工匠的博客-CSDN博客

No code "EPSG:4490" from authority "EPSG" found for object of type "EngineeringCRS".解决方案_徐先森的博客-CSDN博客