Java 将 map 添加到列表会导致多次添加相同的 map

我试图从csv text file中读取一个表，并用java生成一个表(Hashmap中的List个).

为此，我读取文本文件的每个line，从line中构造一个Hashmap<String, String>记录，并在每次迭代结束时将其附加到ArrayList.

我希望文本文件中每一行的一个实例在列表中只出现一次，但得到的只是文本文件中出现n+1次的最后一行，n是最后一行号.

代码如下:

public static void main(String[] args) throws IOException {
    
    FileReader filObj = null;
    try {
        filObj = new FileReader(new File(System.getProperty("user.home") + "\\Desktop\\testData.txt"));
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    }
    
    BufferedReader br = new BufferedReader(filObj);
    
    List<String> headers = new ArrayList<String>();
    List<HashMap<String, String>> myTable = new ArrayList<HashMap<String, String>>();
    HashMap<String, String> myRecord = new HashMap<String, String>();
    
    String line = null;
    int ext = 0;
    while ((line = br.readLine()) != null) {
        //System.out.println(line);
        if (ext == 0) {
            headers = Arrays.asList(line.split(","));
        } else {
            int index = 0;
            for (String each : line.split(",")) {
                myRecord.put(headers.get(index), each);
                index++;
            }
            System.out.println("myrecord:" + myRecord);
        }
        myTable.add(myRecord);
        ext++;
        System.out.println("My Table:" + myTable);
    }
}

testData.txt个文件内容如下

TransactionNumber,TransactionType,Amount,TransactionDate,TransactionRemarks
123456,Credit,4000,07/10/2021,Salary Credited
123333,Debit,7000,05/10/2021,Fuel
123446,Credit,3000,01/10/2021,Refund

控制台输出如下:

My Table:[{}]
myrecord:{TransactionType=Credit, TransactionNumber=123456, Amount=4000, TransactionRemarks=Salary Credited, TransactionDate=07/10/2021}
My Table:[{TransactionType=Credit, TransactionNumber=123456, Amount=4000, TransactionRemarks=Salary Credited, TransactionDate=07/10/2021}, {TransactionType=Credit, TransactionNumber=123456, Amount=4000, TransactionRemarks=Salary Credited, TransactionDate=07/10/2021}]
myrecord:{TransactionType=Debit, TransactionNumber=123333, Amount=7000, TransactionRemarks=Fuel, TransactionDate=05/10/2021}
My Table:[{TransactionType=Debit, TransactionNumber=123333, Amount=7000, TransactionRemarks=Fuel, TransactionDate=05/10/2021}, {TransactionType=Debit, TransactionNumber=123333, Amount=7000, TransactionRemarks=Fuel, TransactionDate=05/10/2021}, {TransactionType=Debit, TransactionNumber=123333, Amount=7000, TransactionRemarks=Fuel, TransactionDate=05/10/2021}]
myrecord:{TransactionType=Credit, TransactionNumber=123446, Amount=3000, TransactionRemarks=Refund, TransactionDate=01/10/2021}
My Table:[{TransactionType=Credit, TransactionNumber=123446, Amount=3000, TransactionRemarks=Refund, TransactionDate=01/10/2021}, {TransactionType=Credit, TransactionNumber=123446, Amount=3000, TransactionRemarks=Refund, TransactionDate=01/10/2021}, {TransactionType=Credit, TransactionNumber=123446, Amount=3000, TransactionRemarks=Refund, TransactionDate=01/10/2021}, {TransactionType=Credit, TransactionNumber=123446, Amount=3000, TransactionRemarks=Refund, TransactionDate=01/10/2021}]