HashSet输出不匹配[JAVA]

Question

代码是从文件中读取并生成HashSet，然后输出到控制台。

我的代码输出和期望的输出不匹配

我的java代码是

Main.java

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader brf = new BufferedReader(new FileReader("calllog.txt"));

        Set<String> phoneNumberList = new HashSet<String>();

        String read = "";
        while ((read = brf.readLine()) != null) {
            String[] callList = read.split(",");

            String in = callList[0];
            phoneNumberList.add(in);     //add(new CallLog(callList[0], startTime, endTime));

        }
        brf.close();
        Iterator<String> itr = phoneNumberList.iterator();
        while(itr.hasNext()){
            System.out.println(itr.next());
        }

    }
}

calllog.txt

8123456789,10-10-2015 10:00:00,10-10-2015 10:28:59
8123456789,11-10-2015 11:00:00,10-10-2015 11:51:00
8123456789,12-10-2015 12:00:00,10-10-2015 12:10:35
9123456789,11-10-2015 11:00:00,11-10-2015 11:32:43
0422-201430,12-10-2015 12:00:00,12-10-2015 11:05:16
0422-201430,12-10-2015 12:06:00,12-10-2015 11:10:20
9764318520,13-10-2015 13:00:00,13-10-2015 10:10:15
0422-201430,12-10-2015 12:00:00,12-10-2015 12:05:16
0422-201430,13-10-2015 14:05:00,13-10-2015 14:15:00
0422-201430,15-10-2015 16:08:00,15-10-2015 16:35:57

输出

9123456789
9764318520
0422-201430
8123456789

预期输出

8123456789
9764318520
0422-201430
9123456789

Answer 1

HashSet是无序的，因此您没有理由期望元素有一定的顺序。

如果你想让元素按照插入顺序排列，你可以使用LinkedHashSet，但这会给你

8123456789
9123456789
0422-201430
9764318520

不是您期望的顺序