干货!使用Geotools解析shap数据实例

本文将重点介绍基于Java和Geotools来解析shap文件，并打印解析内容的过程。

环境：jdk 1.8  

          maven 3.3

第一步、pom.xml 设置

<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>com.yelang</groupId>
	<artifactId>geotools-demo1</artifactId>
	<version>0.0.1-SNAPSHOT</version>

	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<geotools.version>24.0</geotools.version>
	</properties>

	<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>

	<dependencies>
		<dependency>
			<groupId>junit</groupId>
			<artifactId>junit</artifactId>
			<version>4.13.1</version>
			<scope>test</scope>
		</dependency>
		<dependency>
			<groupId>org.geotools</groupId>
			<artifactId>gt-shapefile</artifactId>
			<version>${geotools.version}</version>
		</dependency>
		<dependency>
			<groupId>org.geotools</groupId>
			<artifactId>gt-swing</artifactId>
			<version>${geotools.version}</version>
		</dependency>
	</dependencies>

</project>

提示：geotools依赖包在中央仓库中不存在，如果不设置私有仓库，jar会无法下载。解决办法有两种：第一种是在pom中设置私有仓库地址；第二种是在maven的setttings.xml中设置私服镜像。需要注意的是，镜像的设置mirrorOf一定不要设置*,否则无法下载依赖。推荐如下

<mirror>
    <id>nexus-aliyun</id>
    <mirrorOf>central</mirrorOf>
    <name>Nexus aliyun</name>
    <url>http://maven.aliyun.com/nexus/content/groups/public</url>
  </mirror> 

第二步、解析shap文件

package com.yelang;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.geotools.data.FileDataStore;
import org.geotools.data.FileDataStoreFinder;
import org.geotools.data.simple.SimpleFeatureCollection;
import org.geotools.data.simple.SimpleFeatureIterator;
import org.geotools.data.simple.SimpleFeatureSource;
import org.junit.Test;
import org.opengis.feature.Property;
import org.opengis.feature.simple.SimpleFeature;
public class ReadShapTest {
	@Test
	public void readShap() throws IOException {
		long startTime=System.currentTimeMillis();
        //加载文件
		String filePath = "D:/cesium code/数据/矢量数据/0319点.shp";
        File file = new File(filePath);
        if (!file.exists()) {
        	System.out.println("文件不存在");
        	return;
        }
        //map记录shapefile key-value数据
        List<Map<String,Object>> list = new ArrayList<Map<String, Object>>();
        //通过store获取featurecollection
        FileDataStore store = FileDataStoreFinder.getDataStore(file);
       
        SimpleFeatureSource featureSource = store.getFeatureSource();
        SimpleFeatureCollection simpleFeatureCollection=featureSource.getFeatures();
        SimpleFeatureIterator itertor = simpleFeatureCollection.features();
        //遍历featurecollection
        while (itertor.hasNext()){
            Map<String,Object> data  = new HashMap<String, Object>();
            SimpleFeature feature = itertor.next();
            Collection<Property> p = feature.getProperties();
            Iterator<Property> it = p.iterator();
            //遍历feature的properties
            while(it.hasNext()) {
                Property pro = it.next();
                if(null != pro && null != pro.getValue()) {
                	String field = pro.getName().toString();
                	String value = pro.getValue().toString();
                	field = field.equals("the_geom")?"wkt":field;
                	byte[]bytes=value.getBytes("iso8859-1");
                	value=new String(bytes, "gbk");
                	System.out.println(new String(field.getBytes("iso8859-1"),"gbk") + "==" + value);
                	data.put(field, value);
                }
            }
            list.add(data);
        }
        long endTime=System.currentTimeMillis();
        System.out.println("当前程序耗时："+(endTime-startTime)+"ms");
	}
}

第三步、查看输出结果

第四步、使用GUI工具查看结果

代码如下：

package com.yelang;
import java.io.File;
import java.io.IOException;
import org.geotools.data.FileDataStore;
import org.geotools.data.FileDataStoreFinder;
import org.geotools.data.simple.SimpleFeatureSource;
import org.geotools.map.FeatureLayer;
import org.geotools.map.Layer;
import org.geotools.map.MapContent;
import org.geotools.styling.SLD;
import org.geotools.styling.Style;
import org.geotools.swing.JMapFrame;
import org.geotools.swing.data.JFileDataStoreChooser;
public class ReadShapGui {
	public static void main(String[] args) throws IOException {
		// display a data store file chooser dialog for shapefiles
		File file = JFileDataStoreChooser.showOpenFile("shp", null);
		if (file == null) {
			return;
		}
		FileDataStore store = FileDataStoreFinder.getDataStore(file);
		SimpleFeatureSource featureSource = store.getFeatureSource();
		// Create a map content and add our shapefile to it
		MapContent map = new MapContent();
		map.setTitle("Quickstart");
		Style style = SLD.createSimpleStyle(featureSource.getSchema());
		Layer layer = new FeatureLayer(featureSource, style);
		map.addLayer(layer);
		// Now display the map
		JMapFrame.showMap(map);
	}
}

通过以上几步，可掌握通过geotools读取数据，并进行展示的方法。