本文介绍了如何使用Java JTS将线串每x米分成几部分的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我正在尝试将JTS和postgis用于基于spring的后端.虽然我了解JTS的基础知识,但我不知道如何实现
I'm trying to use JTS and postgis for backend based on spring.While I know basics of JTS I don't know how to achieve
推荐答案
我还需要编写split函数,因此我在stackoverflow上找到了解决方案,但找不到一些有用的信息.因此,我编写了follow方法并回答了您的问题;
i also need to write the split function,so i find solution on stackoverflow,but not find some useful information.so i write follow method and answer your question;
public List<LineString> lineSplit(LineString lineString,double meters) {
List<LineString> results = new ArrayList<>();
List<LineSegment> segments = new ArrayList<>();
// first split linestring to segements[]
for(int i = 1; i < lineString.getCoordinates().length; i++){
segments.add(new LineSegment(lineString.getCoordinates()[i-1], lineString.getCoordinates()[i]));
}
// remainLegnth means that last segment's length dont enough to split to one segement which length is meters
// neededLength means that current segment need how many meters to create a new segment
double remainLength = 0D;
double neededLength = 0D;
// remainCoors means that if the last iteartor dont create a new segment,also mean last segment
// is too short ,even add remains length can't create a new segment;so, we should add this segment's start
// point and end point to remainCoors
List<Coordinate> remainCoors = new ArrayList<>();
// netxStartPoint to store the next segment's start point
Coordinate netxStartPoint = null;
for(int i=0;i<segments.size();i++) {
LineSegment seg = segments.get(i);
neededLength = meters-remainLength;
remainLength += seg.getLength();
netxStartPoint = seg.p0;
while(remainLength>=meters) {
remainCoors.add(netxStartPoint);
Coordinate endPoint = seg.pointAlong(neededLength/seg.getLength());
// to remove the adjacent and same vertx
for(int j=0;j<remainCoors.size()-1;j++) {
if(remainCoors.get(j).equals(remainCoors.get(j+1))) {
remainCoors.remove(j);
}
}
remainCoors.add(endPoint);
results.add(lineString.getFactory().createLineString(remainCoors.toArray(new Coordinate[remainCoors.size()])));
remainCoors = new ArrayList<>();
netxStartPoint = endPoint;
remainLength -= meters;
neededLength += meters;
}
remainCoors.add(netxStartPoint);
remainCoors.add(seg.p1);
}
for(int j=0;j<remainCoors.size()-1;j++) {
if(remainCoors.get(j).equals(remainCoors.get(j+1))) {
remainCoors.remove(j);
}
}
if(remainCoors.size()>=2) {
results.add(lineString.getFactory().createLineString(remainCoors.toArray(new Coordinate[remainCoors.size()])));
}
return results;
}
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