java 实现百度地图的聚合功能

我就是我 2021-09-28 12:26 720阅读 0赞

出于某种原因，需要把百度地图中的聚合方法在java中实现，自己写了一份。

当时做的功能是把聚合后的点存入数据库中，并且需要计算的数值比较多，因此显得麻烦些，我已经把代码进行了一些删减。（本来是想提供一个更纯净的版本的，但是这个两年前的代码，实在是有点忘了，并且现在也并不需要使用，不打算再读一遍。等真正需要的时候再重写一份吧。）

其中DaoHelper是调用sql的公共方法，IClusterOpt 存储一些配置信息，比如地图缩放比等等。

import java.util.ArrayList;
    import java.util.HashMap;
    import java.util.LinkedList;
    import java.util.List;
    import java.util.Map;
    
    import com.DaoHelper;
    import com.util.bean.IClusterOpt;
    import com.XUtils;
    /** * 基于半径的点聚合 * @author Administrator */
    public class MarkerClusterUtil { 
    
    	//[1:20米，50米，100米，200米，500米，1公里，2公里，5公里，10公里，20公里，25公里，50公里，100公里，200公里，500公里，1000公里，2000公里，5000公里，10000公里]
    	//[19级， 18级，17级， 16级， 15级， 14级， 13级， 12级， 11级， 10级， 9级， 8级， 7级， 6级， 5级， 4级， 3级， 2级， 1级]
    	
    	@SuppressWarnings("unchecked")
    	private Map<String, Double> zoomRadius = new HashMap(){ 
    		{ 
    // this.put("18", 30d);
    // this.put("17", 60d);
    // this.put("16", 120d);
    // this.put("15", 300d);
    // this.put("14", 600d);
    // this.put("13", 1200d);
    // this.put("12", 3000d);
    // this.put("11", 6000d);
    // this.put("10", 12000d);
    // this.put("9", 15000d);
    			
    			this.put("18", 62.5d);
    			this.put("17", 125d);
    			this.put("16", 250d);
    			this.put("15", 625d);
    			this.put("14", 1250d);
    			this.put("13", 2500d);	//12500d
    			this.put("12", 6250d);
    			this.put("11", 12500d);
    			this.put("10", 25000d);
    			this.put("9", 31250d);
    		}
    	};
    	
    	private List<Map<String, String>> markers = new ArrayList<Map<String,String>>();
    	private List<Cluster> clusters = new ArrayList(2048);
    	private String[] zooms;
    	
    	private String sql;
    	private DaoHelper daoHelper = XUtils.getDaoHelper();
    	/** * select '20171212', '2101', '17', */
    	private StringBuffer aSql;
    	
    	public void createCluster(List<Map<String, String>> markers, IClusterOpt opt) throws Exception{ 
    		this.clusters = new ArrayList(2048);
    		this.markers = markers;
    		this.zooms = opt.getZooms();
    		
    		//check
    		if(markers == null || markers.size() == 0){ 
    			throw new Exception("markers null");
    		}
    		for(String tz : zooms){ 
    			if(!zoomRadius.containsKey(tz)){ 
    				throw new Exception("zoom undefined");
    			}
    		}
    		//check
    		
    		
    		StringBuffer sb = new StringBuffer(" select '" + “” + "', '");
    		for(String zoom : this.zooms){ 
    			aSql = new StringBuffer(sb.toString() + "'" + zoom + "', ");
    			Double radius = this.zoomRadius.get(zoom);
    			this.clusters = this.doCluster(markers, radius);
    			this.thisClustersToDb();
    			this.clusters = new ArrayList(2048);
    		}
    	}
    	
    	private void thisClustersToDb(){ 
    		int cacheNum = 20;
    		List<Cluster> cacheClusters = new ArrayList(22);
    		for(int i = 0; i < this.clusters.size(); i++){ 
    			cacheClusters.add(this.clusters.get(i));
    			if(i % cacheNum == (cacheNum - 1)){ 
    				this.doInsert(cacheClusters);
    				cacheClusters = new ArrayList(cacheNum + 5);
    			}
    		}
    		this.doInsert(cacheClusters);
    		cacheClusters = new ArrayList(22);
    	}
    	
    	private void doInsert(List<Cluster> cl){ 
    		if(cl == null || cl.size() == 0)
    			return;
    		StringBuffer sb = new StringBuffer();
    		sb.append(" insert into map_cluster(id, zoom, cluster_num, lng, lat, ");
    		sb.append(" gh1_num, kd2_num, gh3_num, kd4_num, ");
    		sb.append(" gh5_num, kd6_num, gh7_fee_a, kd8_fee_a) ");
    		
    		sb.append(" select seq_cluster.nextval, t1.* from ( ");
    		for(int i = 0; i < cl.size(); i++){ 
    			
    			Cluster cluster = cl.get(i);
    			sb.append(this.aSql);
    			sb.append("" + cluster.getExtInfo().get("cNum") + " c , ");
    			sb.append("" + cluster.getCenter().getLng() + " a , ");
    			sb.append("" + cluster.getCenter().getLat() + " b , ");
    			sb.append("" + cluster.getExtInfo().get("a") + " d , ");
    			sb.append("" + cluster.getExtInfo().get("b") + " e , ");
    			sb.append("" + cluster.getExtInfo().get("c") + " f , ");
    			sb.append("" + cluster.getExtInfo().get("d") + " g , ");
    			sb.append("" + cluster.getExtInfo().get("e") + " h , ");
    			sb.append("" + cluster.getExtInfo().get("f") + " i , ");
    			sb.append("" + cluster.getExtInfo().get("g") + " j , ");
    			sb.append("" + cluster.getExtInfo().get("h") + " k ");
    			sb.append(" from dual ");
    			if(i != cl.size() - 1){ 
    				sb.append(" union all ");
    			}
    		}
    		sb.append(" ) t1 ");
    		Map daoMap = new HashMap(2);
    		daoMap.put("sql", sb.toString());
    		System.out.println(daoMap.get("sql"));
    		daoHelper.insert("clusterer.map.cacheSql", daoMap);
    		sb = null;
    	}
    	
    	private List<Cluster> doCluster(List<Map<String, String>> markers, Double radius){ 
    		this.clusters = new ArrayList(2048);
    		
    		for(int i = 0; i < markers.size(); i++){ 
    			int cIndex = -1;
    			Double distance = 99999999d;
    			Point tempMarkerPoint = 
    					new Point(Double.valueOf(markers.get(i).get("m")), Double.valueOf(markers.get(i).get("l")));
    			for(int j = 0; j < this.clusters.size(); j++){ 
    				Double tempDistince = this.clusters.get(j).getDistance(tempMarkerPoint);
    				if(tempDistince < distance){ 
    					distance = tempDistince;
    					cIndex = j;
    				}
    			}
    			
    			if(cIndex == -1 || distance > radius){ 
    				Cluster cluster = new Cluster(tempMarkerPoint, radius, markers.get(i));
    				this.clusters.add(cluster);
    			}else { 
    				this.clusters.get(cIndex).addMarker(markers.get(i), tempMarkerPoint);
    			}
    			
    			if(i % 1000 == 0){ 
    				System.out.println(i);
    			}
    		}
    		
    		for(int i = 0; i < this.clusters.size(); i++){ 
    			this.clusters.get(i).finish();
    		}
    		
    		return this.clusters;
    	}
    	
    	static class Cluster{ 
    		Point center;
    		//String text;
    		Double r;
    		private List<Map<String, String>> markers = new ArrayList<Map<String,String>>(50);
    		Map<String, String> extInfo = new HashMap(16);
    		
    		Cluster(Point center, Double r){ 
    			this.center = center;
    			this.r = r;
    		}
    		
    		Cluster(Point center, Double r, Map<String, String> marker){ 
    			this.center = center;
    			this.r = r;
    			this.markers.add(marker);
    		}
    		
    		private void updateCenter(Point point){ 
    			this.center.setLng(this.center.getLng() * this.markers.size() / (this.markers.size() + 1) + 
    					point.getLng() / (this.markers.size() + 1));
    			this.center.setLat(this.center.getLat() * this.markers.size() / (this.markers.size() + 1) + 
    					point.getLat() / (this.markers.size() + 1));
    		}
    		
    		public void finish(){ 
    			Double a = 0d;
    			Double b = 0d;
    			Double c = 0d;
    			Double d = 0d;
    			Double e = 0d;
    			Double f = 0d;
    			Double g = 0d;
    			Double h = 0d;
    			for(int i = 0; i < this.markers.size(); i++){ 
    				a += Double.valueOf(this.markers.get(i).get("A"));
    				b += Double.valueOf(this.markers.get(i).get("B"));
    				c += Double.valueOf(this.markers.get(i).get("C"));
    				d += Double.valueOf(this.markers.get(i).get("D"));
    				e += Double.valueOf(this.markers.get(i).get("E"));
    				f += Double.valueOf(this.markers.get(i).get("F"));
    				g += Double.valueOf(this.markers.get(i).get("G"));
    				h += Double.valueOf(this.markers.get(i).get("H"));
    			}
    			this.extInfo.put("cNum", this.markers.size() + "");
    			this.extInfo.put("a", a + "");
    			this.extInfo.put("b", b + "");
    			this.extInfo.put("c", c + "");
    			this.extInfo.put("d", d + "");
    			this.extInfo.put("e", e + "");
    			this.extInfo.put("f", f + "");
    			this.extInfo.put("g", g + "");
    			this.extInfo.put("h", h + "");
    			
    			this.markers = null;
    		}
    		
    		public void addMarker(Map<String, String> allInfo, Point point){ 
    			this.updateCenter(point);
    			this.markers.add(allInfo);
    		}
    		
    		public boolean isPointContains(Point point){ 
    			return getDistance(point) < r ? true : false;
    		}
    		
    		public Double getDistance(Point point){ 
    			return MapUtil.getDistance(center.getLat(), center.getLng(), point.getLat(), point.getLng());
    		}
    		
    // public void addExtInfo(String key, String value){ 
    // if(this.extNumInfo.containsKey(key))
    // this.extNumInfo.put(key, this.extNumInfo.get(key) + value);
    // else
    // this.extNumInfo.put(key, value);
    // }
    		
    		public Point getCenter() { 
    			return center;
    		}
    		public void setCenter(Point center) { 
    			this.center = center;
    		}
    // public String getText() { 
    // return text;
    // }
    // public void setText(String text) { 
    // this.text = text;
    // }
    		public double getR() { 
    			return r;
    		}
    		public void setR(Double r) { 
    			this.r = r;
    		}
    
    		public Map<String, String> getExtInfo() { 
    			return extInfo;
    		}
    		
    		
    	}
    	
    	static class Point{ 
    		double lng;
    		double lat;
    		Point(double lng, double lat){ 
    			this.lng = lng;
    			this.lat = lat;
    		}
    		public double getLng() { 
    			return lng;
    		}
    		public void setLng(double lng) { 
    			this.lng = lng;
    		}
    		public double getLat() { 
    			return lat;
    		}
    		public void setLat(double lat) { 
    			this.lat = lat;
    		}
    		
    	}
    
    	public String getSql() { 
    		return sql;
    	}
    	
    	
    }