讀取Demo：

public static void main(String[] args) {
    File csv = new File("C:\\Result.csv");  // CSV檔案路徑
BufferedReader br = null;
    try {
        br = new BufferedReader(new FileReader(csv));
} catch (FileNotFoundException e) {
        e.printStackTrace();
}
    String line = "";
String everyLine = ""
 
;
    try {
        List<String> allString = new ArrayList<>();
        while ((line = br.readLine()) != null)  //讀取到的內容給line變數
{
            everyLine = line;
System.out.println(everyLine);
allString.add(everyLine);
}
        System.out.println("csv表格中所有行數：" + allString.size());
} catch (IOException e) {
        e.printStackTrace();
 
}

}

寫入Demo：

public static void main(String[] args) {
    try {
        File csv = new File("C://writers.csv");//CSV檔案
BufferedWriter bw = new BufferedWriter(new FileWriter(csv, true));
//新增一行資料
bw.newLine();
bw.write("abc" + "," + "123" + "," + "1234");
bw.close();
} catch (FileNotFoundException e) {
        //
 
捕獲File物件生成時的異常
e.printStackTrace();
} catch (IOException e) {
        //捕獲BufferedWriter物件關閉時的異常
e.printStackTrace();
}
}