前言
使用Android Runtime SDK For Java读写ShapeFile文件发现没有可以直接调用的接口去实现功能,所以就用GeoTools开源的项目进行ShapeFile文件的读取,但是发现读出来的图形是ArcGIS无法识别的。所以就要求我将GeoTools读出的图形转换成ArcGis能够识别的图形并存储起来。
过程简述
- 读取ShapeFile文件
- 将GeoTools获取的Geometry转换为WKT格式
- 将WKT转换成ArcGIS能够识别的Json格式
- 通过ArcGIS API中方法读取Json转换为可识别的Geometry
WKT -> Json
首先我们要知道图形分为:POINT、MULTIPOINT、LINESTRING、MULTILINESTRING、POLYGON、MULTIPOLYGON这几种类型。对应的ArcGis对于不同类型所需的JSON格式也不相同。 首先我们先构造这几种类型的实体类: PointObject类:
package com.wkt;
import java.util.HashMap;
public class PointObject {
private double x;
private double y;
private HashMap<String, Integer> spatialReference;
public double getX() {
return x;
}
public void setX(double x) {
this.x = x;
}
public double getY() {
return y;
}
public void setY(double y) {
this.y = y;
}
public HashMap<String, Integer> getSpatialReference() {
return spatialReference;
}
public void setSpatialReference(HashMap<String, Integer> spatialReference) {
this.spatialReference = spatialReference;
}
}
MultiIPointObject类:
package com.wkt;
import java.util.HashMap;
import java.util.List;
public class MultiIPointObject {
private List<Double[]> points;
private HashMap<String, Integer> spatialReference;
public List<Double[]> getPoints() {
return points;
}
public void setPoints(List<Double[]> points) {
this.points = points;
}
public HashMap<String, Integer> getSpatialReference() {
return spatialReference;
}
public void setSpatialReference(HashMap<String, Integer> spatialReference) {
this.spatialReference = spatialReference;
}
}
LineStringObject类:
package com.wkt;
import java.util.HashMap;
import java.util.List;
public class LineStringObject {
private List<List<Double[]>> paths;
private HashMap<String, Integer> spatialReference;
public List<List<Double[]>> getPaths() {
return paths;
}
public void setPaths(List<List<Double[]>> paths) {
this.paths = paths;
}
public HashMap<String, Integer> getSpatialReference() {
return spatialReference;
}
public void setSpatialReference(HashMap<String, Integer> spatialReference) {
this.spatialReference = spatialReference;
}
}
MultLinesStringObject类:
package com.wkt;
import java.util.HashMap;
import java.util.List;
public class MultLinesStringObject {
private List<List<Double[]>> rings;
private HashMap<String, Integer> spatialReference;
public List<List<Double[]>> getRings() {
return rings;
}
public void setRings(List<List<Double[]>> rings) {
this.rings = rings;
}
public HashMap<String, Integer> getSpatialReference() {
return spatialReference;
}
public void setSpatialReference(HashMap<String, Integer> spatialReference) {
this.spatialReference = spatialReference;
}
}
PolygonObject类:
package com.wkt;
import java.util.HashMap;
import java.util.List;
public class PolygonObject {
private List<List<Double[]>> rings;
private HashMap<String, Integer> spatialReference;
public List<List<Double[]>> getRings() {
return rings;
}
public void setRings(List<List<Double[]>> rings) {
this.rings = rings;
}
public HashMap<String, Integer> getSpatialReference() {
return spatialReference;
}
public void setSpatialReference(HashMap<String, Integer> spatialReference) {
this.spatialReference = spatialReference;
}
}
以上就是整个所有类型的实体类了,我通过Google提供的Gson.jar进行JSON转换,得到JSON,下面是不同类型的图形Json转换代码:
package com.wkt;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import com.google.gson.Gson;
public class WKT {
/**
* 点 转换 JSON
*
* @param wkt
* @param wkid
* @return
*/
public String getPOINTWktToJson(String wkt, int wkid) {
String[] strHead = wkt.split("\\(");
String strContent = strHead[1].substring(0, strHead[1].length() - 1);
String[] strResult = strContent.split(" ");
PointObject pointObject = new PointObject();
pointObject.setX(Double.parseDouble(strResult[0]));
pointObject.setY(Double.parseDouble(strResult[1]));
HashMap<String, Integer> spatialReference = new HashMap<String, Integer>();
spatialReference.put("wkid", wkid);
pointObject.setSpatialReference(spatialReference);
Gson gson = new Gson();
return gson.toJson(pointObject);
}
/**
* 多点 转换 JSON
*
* @param wkt
* @param wkid
* @return
*/
public String getMULTIPOINTWktToJson(String wkt, int wkid) {
MultiIPointObject multiIPointObject = new MultiIPointObject();
String ToTailWkt = wkt.substring(0, wkt.length() - 1);
String[] strHead = ToTailWkt.split("\\(\\(");
String strMiddle = strHead[1].substring(0, strHead[1].length() - 1);
String[] strMiddles = strMiddle.split(",");
List<Double[]> list = new ArrayList<Double[]>();
for (int i = 0; i < strMiddles.length; i++) {
if (i == 0) {
String item = strMiddles[i].substring(0,
strMiddles[i].length() - 1);
String[] items = item.split(" ");
Double[] listResult = new Double[] {
Double.parseDouble(items[0]),
Double.parseDouble(items[1]) };
list.add(listResult);
} else if (i == strMiddles.length) {
String item = strMiddles[i]
.substring(1, strMiddles[i].length());
String[] items = item.split(" ");
Double[] listResult = new Double[] {
Double.parseDouble(items[0]),
Double.parseDouble(items[1]) };
list.add(listResult);
} else {
String strItem = strMiddles[i].trim();
String item = strItem.substring(1, strItem.length() - 1);
String[] items = item.split(" ");
Double[] listResult = new Double[] {
Double.parseDouble(items[0]),
Double.parseDouble(items[1]) };
list.add(listResult);
}
}
HashMap<String, Integer> spatialReference = new HashMap<String, Integer>();
spatialReference.put("wkid", wkid);
multiIPointObject.setPoints(list);
multiIPointObject.setSpatialReference(spatialReference);
Gson gson = new Gson();
return gson.toJson(multiIPointObject);
}
/**
* 线 转换 JSON
*
* @param wkt
* @param wkid
* @return
*/
public String getLINESTRINGWktToJson(String wkt, int wkid) {
LineStringObject lineStringObject = new LineStringObject();
List<List<Double[]>> lists = new ArrayList<List<Double[]>>();
List<Double[]> list = new ArrayList<Double[]>();
String[] strHead = wkt.split("\\(");
String strContent = strHead[1].substring(0, strHead[1].length() - 1);
String[] strResult = strContent.split(",");
for (int i = 0; i < strResult.length; i++) {
String itme = strResult[i].trim();
String[] items = itme.split(" ");
Double[] listResult = new Double[] { Double.parseDouble(items[0]),
Double.parseDouble(items[1]) };
list.add(listResult);
}
lists.add(list);
HashMap<String, Integer> spatialReference = new HashMap<String, Integer>();
spatialReference.put("wkid", wkid);
lineStringObject.setPaths(lists);
lineStringObject.setSpatialReference(spatialReference);
Gson gson = new Gson();
return gson.toJson(lineStringObject);
}
/**
* 多线 转换 JSON
*
* @param wkt
* @param wkid
* @return
*/
public String getMULTILINESTRINGWktToJson(String wkt, int wkid) {
MultLinesStringObject lineStringObject = new MultLinesStringObject();
List<List<Double[]>> lists = new ArrayList<List<Double[]>>();
String ToTailWkt = wkt.substring(0, wkt.length() - 1);
String[] strHead = ToTailWkt.split("\\(", 2);
String[] strList = strHead[1].split("\\),\\(");
for (int i = 0; i < strList.length; i++) {
String item = strList[i].trim();
item = item.substring(1, item.length() - 1);
String[] items = item.split(",");
List<Double[]> list = new ArrayList<Double[]>();
for (int j = 0; j < items.length; j++) {
String jItem = items[j].trim();
String[] jItems = jItem.split(" ");
Double[] listResult = new Double[] {
Double.parseDouble(jItems[0]),
Double.parseDouble(jItems[1]) };
list.add(listResult);
}
lists.add(list);
}
HashMap<String, Integer> spatialReference = new HashMap<String, Integer>();
spatialReference.put("wkid", wkid);
lineStringObject.setRings(lists);
lineStringObject.setSpatialReference(spatialReference);
Gson gson = new Gson();
return gson.toJson(lineStringObject);
}
public String getPOLYGONWktToJson(String wkt, int wkid) {
PolygonObject polygonObject = new PolygonObject();
List<List<Double[]>> lists = new ArrayList<List<Double[]>>();
String ToTailWkt = wkt.substring(0, wkt.length() - 1);
String[] strHead = ToTailWkt.split("\\(", 2);
String[] strList = strHead[1].split("\\), \\(");
for (int i = 0; i < strList.length; i++) {
String item = strList[i].trim();
item = item.substring(1, item.length() - 1);
String[] items = item.split(",");
List<Double[]> list = new ArrayList<Double[]>();
for (int j = 0; j < items.length; j++) {
String jItem = items[j].trim();
String[] jItems = jItem.split(" ");
Double[] listResult = new Double[] {
Double.parseDouble(jItems[0]),
Double.parseDouble(jItems[1]) };
list.add(listResult);
}
lists.add(list);
}
HashMap<String, Integer> spatialReference = new HashMap<String, Integer>();
spatialReference.put("wkid", wkid);
polygonObject.setRings(lists);
polygonObject.setSpatialReference(spatialReference);
Gson gson = new Gson();
return gson.toJson(polygonObject);
}
public String getMULTIPOLYGONWktToJson(String wkt, int wkid) {
PolygonObject polygonObject = new PolygonObject();
List<List<Double[]>> lists = new ArrayList<List<Double[]>>();
String ToTailWkt = wkt.substring(0, wkt.length() - 1);
String[] strHead = ToTailWkt.split("\\(", 2);
ToTailWkt = strHead[1].substring(0, strHead[1].length() - 1);
String[] strHeads = ToTailWkt.split("\\(", 2);
String[] strList = strHeads[1].split("\\), \\(");
if (strList.length == 1) {
for (int i = 0; i < strList.length; i++) {
String item = strList[i].trim();
item = item.substring(1, item.length() - 1);
String[] items = item.split(",");
List<Double[]> list = new ArrayList<Double[]>();
for (int j = 0; j < items.length; j++) {
String jItem = items[j].trim();
String[] jItems = jItem.split(" ");
Double[] listResult = new Double[] {
Double.parseDouble(jItems[0]),
Double.parseDouble(jItems[1]) };
list.add(listResult);
}
lists.add(list);
}
} else {
for (int i = 0; i < strList.length; i++) {
String item = strList[i].trim();
item = item.substring(1, item.length() - 1);
String[] items = item.split(",");
List<Double[]> list = new ArrayList<Double[]>();
for (int j = 1; j < items.length; j++) {
String jItem = items[j].trim();
String[] jItems = jItem.split(" ");
Double[] listResult = new Double[] {
Double.parseDouble(jItems[0]),
Double.parseDouble(jItems[1]) };
list.add(listResult);
}
lists.add(list);
}
}
HashMap<String, Integer> spatialReference = new HashMap<String, Integer>();
spatialReference.put("wkid", wkid);
polygonObject.setRings(lists);
polygonObject.setSpatialReference(spatialReference);
Gson gson = new Gson();
return gson.toJson(polygonObject);
}
}
JSON - > Geometry
以上JSON转换完毕后再ArcGis For Android API中有一个方法可以将JSON直接转换为 Geometry。
MapGeometry mapGeometry = GeometryEngine.jsonToGeometry(jsonParser);
Geometry geometry = mapGeometry.getGeometry();
以上就将WKT转换成了ArcGIS能够操作的Geometry了,通过这种方式得到的Geometry哪怕是带了岛或者洞或者多多边形的图形都可以正常显示。
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