相关疑难解决方法(0)

我已经设法使用Java 8 Streams API编写解决方案,该解决方案首先按对象组合对象Route列表,然后计算每个组中对象的数量.它返回一个映射Route - > Long.这是代码:

Map<Route, Long> routesCounted = routes.stream()
                .collect(Collectors.groupingBy(gr -> gr, Collectors.counting()));

而Route类:

public class Route implements Comparable<Route> {
    private long lastUpdated;
    private Cell startCell;
    private Cell endCell;
    private int dropOffSize;

    public Route(Cell startCell, Cell endCell, long lastUpdated) {
        this.startCell = startCell;
        this.endCell = endCell;
        this.lastUpdated = lastUpdated;
    }

    public long getLastUpdated() {
        return this.lastUpdated;
    }

    public void setLastUpdated(long lastUpdated) {
        this.lastUpdated = lastUpdated;
    }

    public Cell getStartCell() {
        return startCell;
    }

    public void setStartCell(Cell startCell) …