dxf转geojson后，使用java代码找出dxf每个图层中的标志性图标（三角形、四边形等等）

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我是靠谱客的博主勤劳可乐，最近开发中收集的这篇文章主要介绍dxf转geojson后，使用java代码找出dxf每个图层中的标志性图标（三角形、四边形等等），觉得挺不错的，现在分享给大家，希望可以做个参考。

概述

第一步：先熟悉geojson的数据结构

geojson将所有的地理要素分为Point、MultiPoint、LineString、MultiLineString、Polygon、MultiPolygon、GeometryCollection。

感觉有篇博文讲的挺好，大家可以去看一下geojson数据结构讲解

第二步：试图使用Java代码去获取json里面你想要的图层里面的数据

我之前写过一篇根据Java代码获取json数据的文章，大家可以去看一下java操作json文件

第三步：开始分析你想要找的图标有什么特点

//这代表一个三角形
{
"geometry": {
"geometries": [{
"coordinates": [
[19776.669056702118, 32717.534270796306, 9.181425E-9],
[20103.606839973643, 32717.534325811146, 9.181425E-9]
],
"type": "LineString"
}, {
"coordinates": [
[19776.669056702118, 32717.534270796306, 9.181425E-9],
[19940.13805881275, 32417.534298303737, 9.181425E-9]
],
"type": "LineString"
}, {
"coordinates": [
[19940.13805881275, 32417.534298303737, 9.181425E-9],
[20103.606839973643, 32717.534325811146, 9.181425E-9]
],
"type": "LineString"
}, {
"coordinates": [
[19834.25117925165, 32717.534280485826, 9.181425E-9],
[19834.251181033436, 32706.94559757729, 9.181425E-9]
],
"type": "LineString"
},
。。。。。。。。
, {
"coordinates": [
[19940.138027930516, 32601.05878631602, 9.181425E-9],
[19940.138045748416, 32495.171957236857, 9.181425E-9]
],
"type": "LineString"
}, {
"coordinates": [
[20046.02483741, 32717.53431612164, 9.181425E-9],
[20046.02483919179, 32706.945633213105, 9.181425E-9]
],
"type": "LineString"
},
{
"coordinates": [19940.138045748416, 32495.171957236857, 9.181425E-9],
"type": "Point"
}, {
"coordinates": [19940.138010112612, 32706.945615395198, 9.181425E-9],
"type": "Point"
}],
"type": "GeometryCollection"
},
"type": "Feature",
"properties": {
"ExtendedEntity": null,
"SubClasses": "AcDbEntity:AcDbBlockReference",
"Text": null,
"EntityHandle": "3DA17",
"Linetype": null,
"Layer": "I-POWER"
}
},

这是一个三角形在json文件中的数据结构，我找了几个对比了一下，发现每个三角形的三个边都是三条线组成

{
"coordinates": [
[19776.669056702118, 32717.534270796306, 9.181425E-9],
[20103.606839973643, 32717.534325811146, 9.181425E-9]
],
"type": "LineString"
}, {
"coordinates": [
[19776.669056702118, 32717.534270796306, 9.181425E-9],
[19940.13805881275, 32417.534298303737, 9.181425E-9]
],
"type": "LineString"
}, {
"coordinates": [
[19940.13805881275, 32417.534298303737, 9.181425E-9],
[20103.606839973643, 32717.534325811146, 9.181425E-9]
],
"type": "LineString"
}

就是这三条线，三角形的三条边是根据三个点组成，那就根据这个特点（这三条线的坐标总会有相交的点，就是顶点，两两都有相等的）开始写代码查询。

第四步：上完整代码

package parse;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;
import org.json.JSONException;
import org.json.JSONObject;
import org.json.JSONArray;
//import net.sf.json.JSONArray;
//import net.sf.json.JSONObject;
import java.util.Iterator;
import org.gavaghan.geodesy.Ellipsoid;
import org.gavaghan.geodesy.GeodeticCalculator;
import org.gavaghan.geodesy.GeodeticCurve;
import org.gavaghan.geodesy.GlobalCoordinates;
import java.util.List;
public class JsonConvert {
/**
* @param args
*/
public static void main(String[] args){
int a = 0;
// 读取原始json文件并进行操作和输出

try {
BufferedReader br = new BufferedReader(new FileReader(
"src/json/28f.json"));// 读取原始json文件

String s = null, ws = null;
List<JSONArray> list = new ArrayList<JSONArray>();
while ((s = br.readLine()) != null) {
// System.out.println(s);

try {
JSONObject dataJson = new JSONObject(s);// 创建一个包含原始json串的json对象

JSONArray features = dataJson.getJSONArray("features");// 找到features的json数组
for (int i = 0; i < features.length(); i++) {
JSONObject info = features.getJSONObject(i);// 获取features数组的第i个json对象

JSONObject properties = info.getJSONObject("properties");// 找到properties的json对象

JSONObject geometry = info.getJSONObject("geometry");
String name = properties.getString("Layer");// 读取properties对象里的name字段值
//
if(name.equals("I-FURN")){
//
if(name.equals("I-ROOM-NUB")){
if(name.equals("I-POWER")){
//
a+=digui(geometry).size();
//
list.addAll(digui(geometry));
List<JSONArray> list1 = new ArrayList<JSONArray>();
list1 = digui(geometry);
list.addAll(list1);
for (JSONArray s1 : list1) {
for (JSONArray s2 : list1) {
if(s1.getJSONArray(0).toString().equals(s2.getJSONArray(0).toString())){
for (JSONArray s3 : list1) {
if(s2.getJSONArray(1).toString().equals(s3.getJSONArray(0).toString())){
if(!s1.toString().equals(s2.toString()) && !s1.toString().equals(s3.toString()) && !s2.toString().equals(s3.toString())){
a++;
System.out.println("s1： "+s1+"
s2： "+s2+"
s3： "+s3);
}
}
}
}
}
}
}
}
} catch (JSONException e) {
// TODO Auto-generated catch block

e.printStackTrace();
}
}
br.close();
System.out.println(a);
} catch (Exception e) {
// TODO Auto-generated catch block

e.printStackTrace();
}
//
getJson();
//
getLength();
}
public static void getJson(){
// 读取原始json文件并进行操作和输出

try {
BufferedReader br = new BufferedReader(new FileReader(
"src/json/28f.json"));// 读取原始json文件

BufferedWriter bw = new BufferedWriter(new FileWriter(
"src/json/28f_POWER.json"));// 输出新的json文件

String s = null, ws = null;
while ((s = br.readLine()) != null) {
// System.out.println(s);

try {
JSONObject dataJson = new JSONObject(s);// 创建一个包含原始json串的json对象

JSONArray arr = new JSONArray();
JSONArray features = dataJson.getJSONArray("features");// 找到features的json数组
for (int i = 0; i < features.length(); i++) {
JSONObject info = features.getJSONObject(i);// 获取features数组的第i个json对象

JSONObject properties = info.getJSONObject("properties");// 找到properties的json对象

//
JSONObject geometry = info.getJSONObject("geometry");
String name = properties.getString("Layer");// 读取properties对象里的name字段值
//
if(name.equals("I-FURN")){
if(name.equals("I-POWER")){
//
if(name.equals("I-ROOM-NUB")){
//
if(name.equals("I-POWER")){
//
System.out.println(info);
arr.put(info);
}
}
ws = "{"type": "FeatureCollection""+","+""features":"+arr.toString()+"}";
} catch (JSONException e) {
e.printStackTrace();
}
}
bw.write(ws);
bw.flush();
br.close();
bw.close();
} catch (IOException e) {
// TODO Auto-generated catch block

e.printStackTrace();
}
}
public static List digui(JSONObject obj){
List<JSONArray> list = new ArrayList<JSONArray>();
try{
if(!obj.getString("type").equals("Point") && !obj.getString("type").equals("Polygon")){
//
System.out.println(obj.getJSONArray("coordinates"));
list.add(obj.getJSONArray("coordinates"));
}
}catch(Exception e){
try{
//
System.out.println("geometry"+obj);
JSONArray geometries = obj.getJSONArray("geometries");
for (int j = 0; j < geometries.length(); j++) {
JSONObject jj = geometries.getJSONObject(j);
try{
if(jj.getString("type").equals("LineString")){
//
System.out.println(jj.getJSONArray("coordinates"));
list.add(jj.getJSONArray("coordinates"));
}
//
System.out.println("jj:"+jj);
//
System.out.println(jj.getString("type")+"
");
}catch(Exception es){
if(jj.getJSONArray("geometries").length()>0){
for(int k = 0; k < jj.getJSONArray("geometries").length(); k++){
digui(jj.getJSONArray("geometries").getJSONObject(k));
}
}else{
digui(jj.getJSONObject("geometry"));
}
}
}
}catch(Exception ee){
System.out.println("出错了");
}
}
return list;
}
public static void getLength(){
//
GlobalCoordinates source = new GlobalCoordinates(19776.669056702118, 32717.534270796306);
//
GlobalCoordinates target = new GlobalCoordinates(20103.606839973643, 32717.534325811146);
//
GlobalCoordinates source = new GlobalCoordinates(19776.669056702118, 32717.534270796306);
//
GlobalCoordinates target = new GlobalCoordinates(19940.13805881275, 32417.534298303737);
GlobalCoordinates source = new GlobalCoordinates(61008.986616448245, 27727.143809821988);
GlobalCoordinates target = new GlobalCoordinates(60708.98658894084, 27890.61259098288);
double meter1 = getDistanceMeter(source, target, Ellipsoid.Sphere);
double meter2 = getDistanceMeter(source, target, Ellipsoid.WGS84);
System.out.println("Sphere坐标系计算结果："+meter1 + "米");
System.out.println("WGS84坐标系计算结果："+meter2 + "米");
}
public static double getDistanceMeter(GlobalCoordinates gpsFrom, GlobalCoordinates gpsTo, Ellipsoid ellipsoid){
//创建GeodeticCalculator，调用计算方法，传入坐标系、经纬度用于计算距离
GeodeticCurve geoCurve = new GeodeticCalculator().calculateGeodeticCurve(ellipsoid, gpsFrom, gpsTo);
return geoCurve.getEllipsoidalDistance();
}
}