从每个ArrayList对象具有多个值的ArrayList写入文本文件(java)
我正在尝试将ArrayList保存到文本文件中。但它的保存格式是错误的。我的代码:
ArrayList<Vehicle> vehs = new ArrayList<Vehicle>();
vehs.add(new Vehicle("QJT123", "Starlet 99", 35.0, 190000));
vehs.add(new PremiumVehicle("TUX132", "BWM 05 ", 90.0, 12000, 100, 10000, 5000));
用于以下2项的构造函数:
public PremiumVehicle(String vehicleID, String description, double dailyRate, int odometer, int allowance, int serLength, int lastOdo) //subclass
public Vehicle(String vehicleID, String description, double dailyRate, int odometer) //Superclass
这两项都存储在车辆阵列列表中。要保存到文本文件的代码:
private static void saveFile(ArrayList<Vehicle> vehs){
File fileName = new File("VehicleList.txt");
try {
FileWriter fw = new FileWriter(fileName);
Writer output = new BufferedWriter(fw);
for (int i = 0; i < vehs.size(); i++){
output.write(vehs.get(i).toString() + "\n");
}
output.close();
} catch (Exception e) {
JOptionPane.showMessageDialog(null, "I cannot create that file");
}
}
我在VehicleList中的输出。txt:
vehicle ID = QJT123 Description = Starlet 99 Status = A Daily Rate = 35.0 Odometer reading = 190000vehicle ID = TUX132 Description = BWM 05 Status = A Daily Rate = 90.0 Odometer reading = 12000 Mileage allowance = 100 service length = 10000 Last Service = 5000
如何在写入新的ArrayList对象时添加每一行,例如:
vehicle ID = QJT123 Description = Starlet 99 Status = A Daily Rate = 35.0 Odometer reading = 190000
vehicle ID = TUX132 Description = BWM 05 Status = A Daily Rate = 90.0 Odometer reading = 12000 Mileage allowance = 100 service length = 10000 Last Service = 5000
我试过使用vehs.get(i).toString() + "\n"
,但似乎不起作用
# 1 楼答案
最可能的情况是,您的平台没有将\n视为换行符-这取决于操作系统
获得正确换行标记的一种方法:
或者更简单:
而不是在代码中使用
+ "\n"
# 2 楼答案
BufferedWriter有一个
newLine()
方法,如果将output
声明为BufferedWriter
,则可以使用该方法同样对于该方法的javadoc: