io.github.baozi926.geo.GeoJsonUtil Maven / Gradle / Ivy
package io.github.baozi926.geo;
import cn.hutool.core.io.FileUtil;
import cn.hutool.core.text.CharSequenceUtil;
import cn.hutool.core.util.BooleanUtil;
import cn.hutool.core.util.CharsetUtil;
import cn.hutool.core.util.NumberUtil;
import io.github.baozi926.geo.exception.GeoException;
import org.geotools.data.DataStore;
import org.geotools.data.DataStoreFinder;
import org.geotools.data.DataUtilities;
import org.geotools.data.geojson.GeoJSONDataStoreFactory;
import org.geotools.data.simple.SimpleFeatureCollection;
import org.geotools.data.simple.SimpleFeatureSource;
import org.geotools.feature.FeatureCollection;
import org.geotools.feature.FeatureIterator;
import org.geotools.feature.SchemaException;
import org.geotools.geojson.feature.FeatureJSON;
import org.geotools.geojson.geom.GeometryJSON;
import org.geotools.util.URLs;
import org.locationtech.jts.geom.Geometry;
import org.locationtech.jts.geom.GeometryCollection;
import org.opengis.feature.Feature;
import org.opengis.feature.Property;
import org.opengis.feature.type.FeatureType;
import org.opengis.feature.type.GeometryDescriptor;
import java.io.*;
import java.util.HashMap;
import java.util.Map;
/**
* @author 蔡惠民
*
* 处理geojson的辅助类
*/
public class GeoJsonUtil {
private GeoJsonUtil() {
throw new IllegalStateException("Utility class");
}
/**
* convert geojson string to geometry
*
* @param geometry geometry
* @return geojson string
* @throws IOException IOException
*/
public static String geometry2GeoJson(Geometry geometry) throws IOException {
GeometryJSON geometryJson = new GeometryJSON();
StringWriter writer = new StringWriter();
geometryJson.write(geometry, writer);
writer.close();
return writer.toString();
}
/**
* convert geometry to geojson string
*
* @param geojsonString geojson string
* @return geometry
* @throws IOException IOException
*/
public static Geometry geoJson2Geometry(String geojsonString) throws IOException {
if (geojsonString == null) {
return null;
}
GeometryJSON gjson = new GeometryJSON();
Reader reader = new StringReader(geojsonString);
Geometry geometry = gjson.read(reader);
geometry.setSRID(4326); //默认为4326
return geometry;
}
/**
* 将geojson对象转换为要素集合
* 尽量使用 fromJsonAsSimpleFeatureCollection
*
* @param geojsonString geojson 字符串
* @param decimals 精确到小数点后的位数
* @return FeatureCollection
* @throws GeoException GeoException
*/
public static FeatureCollection fromJson(String geojsonString, int decimals) throws GeoException {
return (FeatureCollection) fromJsonAsSimpleFeatureCollection(geojsonString, decimals);
}
/**
* 将geojson文件转换为要素集合，这个结果中是可以区分 Multi和Single的，但是fromJson那个方法会将所有 geometry类型统一成第一个要素的geometry类型，所以这个方法是优于fromJson，应优先使用
* get SimpleFeatureCollection from geojson file
*
* @param inFile geojson 文件
* @return SimpleFeatureCollection
* @throws IOException IOException
*/
public static SimpleFeatureCollection fromFile(File inFile) throws IOException {
Map params = new HashMap<>();
params.put(GeoJSONDataStoreFactory.URL_PARAM.key, URLs.fileToUrl(inFile));
DataStore newDataStore = DataStoreFinder.getDataStore(params);
SimpleFeatureSource featureSource = newDataStore.getFeatureSource(newDataStore.getTypeNames()[0]);
return featureSource.getFeatures();
}
/**
* 将geojson对象转换为要素集合
* get featureCollection from geojson string
*
* @param geojsonString geojson string
* @return geojson string
* @throws GeoException see in msg
*/
public static FeatureCollection fromJson(String geojsonString) throws GeoException {
return fromJson(geojsonString, GeoConstants.GEOJSON_COORDINATES_ACCURACY);
}
/**
* 根据属性字段合并geojson
*
* merge by field
*
* @param geojsonStr geojson 的字符串
* @param mergeField 合并的属性
* @param mergeFieldType 指定合并属性的类型
* @param forceMergeField2NumberIfCan 是否在可以将合并属性转换成数字的时候转换成数字
* @return geojson string
* @throws GeoException see in msg
* @throws SchemaException SchemaException
* @author caihuimin
*/
public static String mergeByField(String geojsonStr, String mergeField, String mergeFieldType, Boolean forceMergeField2NumberIfCan) throws GeoException, SchemaException {
FeatureCollection featureCollection = fromJson(geojsonStr, GeoConstants.GEOJSON_COORDINATES_ACCURACY);
if (BooleanUtil.isTrue(forceMergeField2NumberIfCan) && mergeFieldType == null && featureCollection.size() > 0) {
FeatureIterator featureIterator = featureCollection.features();
if (featureIterator.hasNext()) {
Feature feature = featureIterator.next();
Property val = feature.getProperty(mergeField);
if (val != null && val.getValue() != null && NumberUtil.isNumber(val.getValue().toString())) {
//暂定都是Double，因为也能涵盖Integer的情况
mergeFieldType = "Double";
}
}
featureIterator.close();
}
String geometryType = featureCollection.getSchema().getGeometryDescriptor().getType().getBinding().getSimpleName();
featureCollection.getSchema().getDescriptor("mergeField");
FeatureCollection result = FeatureCollectionUtil.mergeByField(featureCollection, mergeField, getMultiGeometryType(geometryType), mergeFieldType);
return toString(result, GeoConstants.GEOJSON_COORDINATES_ACCURACY);
}
/**
* 根据属性字段合并geojson
*
* @param geojsonStr geojson 的字符串
* @param mergeField 合并的属性
* @return geojson string
* @throws GeoException see in msg
* @throws SchemaException 读取schema 失败
* @author caihuimin
*/
public static String mergeByField(String geojsonStr, String mergeField) throws GeoException, SchemaException {
return mergeByField(geojsonStr, mergeField, null, false);
}
/**
* 获取集合类型对应的 Multi类型，例如 输入Point，得到MultiPoint
*
* @param geometryType 几何类型
* @author caihuimin
*/
static String getMultiGeometryType(String geometryType) {
if (CharSequenceUtil.startWith(geometryType, "Multi")) {
return geometryType;
}
return "Multi" + geometryType;
}
/**
* 粗略效验 geojson 字符串
*
* @param geojsonStr geojson 的字符串
* @throws GeoException see in msg
*/
public static void roughCheck(String geojsonStr) throws GeoException {
fromJson(geojsonStr);
}
/**
* 将geojson合并一条数据 （如 n Polygon 得到 1 MultiPolygon）
*
* @param geojsonStr geojson 的字符串
* @return geojson string
* @throws GeoException see in msg
* @author caihuimin
*/
public static String merge(String geojsonStr) throws GeoException {
FeatureCollection featureCollection = fromJson(geojsonStr);
if (featureCollection.getSchema() == null) {
throw new GeoException("无法读取元数据，数据可能是空的！");
}
GeometryDescriptor geometryDescriptor = featureCollection.getSchema().getGeometryDescriptor();
if (geometryDescriptor == null) {
throw new GeoException("无法获取几何图形的元数据，可能数据是空的或者没有geometry字段！");
}
String geometryType = featureCollection.getSchema().getGeometryDescriptor().getType().getBinding().getSimpleName();
FeatureCollection result = FeatureCollectionUtil.union(DataUtilities.collection(featureCollection), getMultiGeometryType(geometryType));
return toString(result);
}
public static String toString(FeatureCollection featureCollection) throws GeoException {
return toString(featureCollection, GeoConstants.GEOJSON_COORDINATES_ACCURACY);
}
/**
* 将featureCollection转换成字符串
*
* @param featureCollection featureCollection
* @param decimals decimals
* @return geojson string
* @throws GeoException see in msg
* @author caihuimin
*/
public static String toString(FeatureCollection featureCollection, int decimals) throws GeoException {
//如果是空值，就返回一个空的featureCollection
if (featureCollection == null || featureCollection.size() == 0) {
return "{\n" +
" \"type\": \"FeatureCollection\",\n" +
" \"features\": []\n" +
"}";
}
FeatureJSON featureJSON = new FeatureJSON(new GeometryJSON(decimals));
if (featureCollection.getSchema() != null) {
boolean geometryLess = featureCollection.getSchema().getGeometryDescriptor() == null;
featureJSON.setEncodeFeatureCollectionBounds(!geometryLess);
featureJSON.setEncodeFeatureCollectionCRS(!geometryLess);
}
StringWriter stringWriter = new StringWriter();
try {
featureJSON.writeFeatureCollection(featureCollection, stringWriter);
} catch (IOException e) {
throw new GeoException("写入geojson失败！", e);
}
return stringWriter.toString();
}
/**
* 校验geojson featureCollection
*
* @param geojsonString geojson的字符串
* @return geojson string
* @throws GeoException see in msg
* @author caihuimin
*/
public static String validate(String geojsonString) throws GeoException {
FeatureCollection featureCollection = fromJson(geojsonString);
FeatureCollection validateFeatures = FeatureCollectionUtil.validate(featureCollection);
return toString(validateFeatures);
}
/**
* 校验geojson featureCollection
*
* @param featureCollection featureCollection
* @return geojson string
* @throws GeoException GeoException
* @author caihuimin
*/
public static String validate(FeatureCollection featureCollection) throws GeoException {
FeatureCollection validateFeatures = FeatureCollectionUtil.validate(featureCollection);
return toString(validateFeatures);
}
/**
* 坐标转换geojson featureCollection
*
* @param geojsonFile geojson的文件
* @param inputCRS 数据本身的坐标系
* @param outputCRS 需要转换成的坐标系
* @return geojson string
* @throws GeoException see in msg
*/
public static String coordinateTransform(File geojsonFile, String inputCRS, String outputCRS) throws GeoException {
return coordinateTransform(FileUtil.readString(geojsonFile, CharsetUtil.UTF_8), inputCRS, outputCRS);
}
/**
* 坐标转换geojson featureCollection
*
* @param geojsonString geojson的字符串
* @param inputCRS 数据本身的坐标系
* @param outputCRS 需要转换成的坐标系
* @return geojson string
* @throws GeoException see in msg
*/
public static String coordinateTransform(String geojsonString, String inputCRS, String outputCRS) throws GeoException {
FeatureCollection featureCollection = fromJson(geojsonString);
if (featureCollection == null || featureCollection.size() == 0) {
return geojsonString;
}
if (featureCollection.getSchema() == null) {
throw new GeoException("schema is null");
}
FeatureCollection result = CoordinateSystemTransformer.transform(featureCollection, inputCRS, outputCRS);
return toString(result);
}
/**
* 将geojson字符串读取成SimpleFeatureCollection
*
* @param geojsonStr geojson的字符串
* @return SimpleFeatureCollection
* @throws GeoException GeoException
* @author caihuimin
*/
public static SimpleFeatureCollection fromJsonAsSimpleFeatureCollection(String geojsonStr) throws GeoException {
return fromJsonAsSimpleFeatureCollection(geojsonStr, GeoConstants.GEOJSON_COORDINATES_ACCURACY);
}
/**
* 将geojson字符串读取成SimpleFeatureCollection
*
* @param geojsonStr geojson的字符串
* @param decimals decimals
* @return SimpleFeatureCollection
* @throws GeoException GeoException
* @author caihuimin
*/
public static SimpleFeatureCollection fromJsonAsSimpleFeatureCollection(String geojsonStr, int decimals) throws GeoException {
GeometryJSON geometryJSON = new GeometryJSON(decimals);
FeatureJSON featureJSON = new FeatureJSON(geometryJSON);
try {
SimpleFeatureCollection simpleFeatureCollection = (SimpleFeatureCollection) featureJSON.readFeatureCollection(geojsonStr);
if (simpleFeatureCollection.size() == 0) {
GeometryCollection geometryCollection;
try {
//用于判断是否是geometryCollection
geometryCollection = geometryJSON.readGeometryCollection(geojsonStr);
} catch (Exception e) {
return simpleFeatureCollection;
}
if (geometryCollection != null && BooleanUtil.isFalse(geometryCollection.isEmpty())) {
throw new GeoException("支持读取FeatureCollection,无法读取GeometryCollection!");
}
}
return simpleFeatureCollection;
} catch (IOException e) {
throw new GeoException("读取geojson失败！", e);
}
}
/**
* 删除geometry为null的
*
* @param geojsonStr geojson的字符串
* @return geojson string
* @throws GeoException see in msg
* @author caihuimin
*/
public static String removeNullGeometryItem(String geojsonStr) throws GeoException {
SimpleFeatureCollection simpleFeatureCollection = GeoJsonUtil.fromJsonAsSimpleFeatureCollection(geojsonStr);
SimpleFeatureCollection featureCollectionWithGeometryNullRemoved = FeatureCollectionUtil.removeNullGeometryItem(simpleFeatureCollection);
return GeoJsonUtil.toString(featureCollectionWithGeometryNullRemoved);
}
}