在ArrayList Java中查找元素

Question

我找不到元素,这是我的代码:

 public static void main(String[] args) {
    BufferedReader br = getFileReader("reader.csv");

    ArrayList<Monitoring> col = getCollection(br);

    //sort the collection on 'beginTime'
    for (Monitoring x : col)
        System.out.println(x.toString());
    BeginTimeComparator beginTime = new BeginTimeComparator();
    Collections.sort(col,beginTime);
    System.out.println("Begin time:");
    for (Monitoring x : col)
        System.out.println(x.toString());

这是我遇到麻烦的部分,我不知道如何搜索使用endTime 2015-03-10获取对象.BTW这是一行cvs数据:

UnitId;BeginTime;EndTime;Type;Min;Max;Sum

14100072; 2015-03-10 07:12:20; 2015-03-10 7:13:20; Gps/GpsAccuracyGyroBias; 0; 0; 0

//find the amount of elements that were sent on 'endTime' = 2015-03-10 (just the date)
    EndTimeComparator endTime = new EndTimeComparator();
    String findThis = "2015-03-10";
    Collections.sort(col, endTime);

    for(Monitoring x : col){
             if(x.getEndTime().equals(findThis)){
                 System.out.println("Here is 'endTime= 2015-03-10' :");
                 System.out.println(x.toString());

             }
    }

我试过这个,但两个都没有用:

int index = Collections.binarySearch(col, findThis.toString(), null);
System.out.println("Here is 'endTime= 2015-03-10' :");
System.out.println(index);

Answer 1

猜测 getEndTime() 返回 LocalDateTime 您无法将字符串与 LocalDateTime 类型进行比较。您可以尝试将 LocalDateTime 解析为 LocalDate 并用 LocalDate 类型填充“findThis”变量。

因为代码说了1000多个字：

EndTimeComparator endTime = new EndTimeComparator();
Collections.sort(col, endTime);

DateTimeFormatter dtf = DateTimeFormatter.ofPattern("yyyy-MM-dd");
LocalDate findThis = LocalDate.parse("2015-03-10", dtf);

System.out.println("Here is 'endTime= 2015-03-10' :");
for (Monitoring x : col) {
    if (x.getEndTime().toLocalDate().equals(findThis)) {

        System.out.println(x.toString());

    }
}