如何通过长尾词实现基于监视器模式的车辆实时追踪？

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java/** * 基于监视器模式的车辆追踪 */public class MonitorVehicleTracker { private final Map locations;

public MonitorVehicleTracker(Map locations) { this.locations=deepCopy(locations); }

public synchronized Map getLocations() { // 返回当前位置的深拷贝，以避免外部修改 return deepCopy(this.locations); }

java concurrent

/** 基于监视器模式的车辆追踪 */ public class MonitorVehicleTracker { private final Map locations; public MonitorVehicleTracker(Map locations) { this.locations = deepCopy(locations); } public synchronized Map getLocations() { return deepCopy(locations); } public synchronized MutablePoint getLocation(String id) { MutablePoint loc = locations.get(id); return loc == null ? null : new MutablePoint(loc); } public synchronized void setLocation(String id, int x, int y) { MutablePoint loc = locations.get(id); if (loc == null) System.out.println("No such ID: " + id); loc.x = x; loc.y = y; } private Map deepCopy(Map m) { Map result = new HashMap (); for (String id : m.keySet()) { result.put(id, new MutablePoint(m.get(id))); } return Collections.unmodifiableMap(result); } }