请给我一些帮助:我正在用Java模拟飞行花名册。名册将容纳25名乘客,其中22名来自文本文件(PassengerList.txt)。对于每个乘客,有3个必需的数据点;名称,座位类别和座位编号以及2个可选数据点常旅客号码和常旅客积分。每个乘客都在自己的线路上,每个数据点都用逗号分隔。例如:
Allen George,Economy Class,8A,#GEO456,10000
Judy Hellman,Economy Class,8B
到目前为止,我拥有此类以及构造函数:
public class Passengers
{
private String name, type, seat, flyernum;
private int points;
//Constructor to intialize the instance data
Passengers(String full_name, String seat_type, String seat_number,
String frequent_flyer_number, int frequent_flyer_points)
{
name=full_name;
type=seat_type;
seat=seat_number;
flyernum=frequent_flyer_number;
points=frequent_flyer_points;
} //end Passengers
我需要做的是从文本文件中读取每一行并创建数组,即,使第一行看起来像这样:
Passenger passenger1 = new Passenger ("Allen George","Economy Class","8A"
,"#GEO456",10000)
进入这样的数组:
Passenger[0] = passenger1;
我显然是Java初学者,但是我已经被这个问题困扰了很长时间了,当我尝试一些新的东西时,我不断收到错误消息。我一直在使用Scanner读取文件。文本文件不需要被覆盖,只需由程序读取和扫描即可。也只能使用数组,ArrayList是不行的。也只有两个文件,Passengers类和main方法。请帮忙!谢谢!
答案 0 :(得分:0)
您可以像下面这样:
首先,您需要一个Passenger.class。看起来像这样(请注意,我已经添加了toString():
public class Passenger {
private String name, type, seat, flyernum;
private int points;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
public String getSeat() {
return seat;
}
public void setSeat(String seat) {
this.seat = seat;
}
public void setFlyernum(String flyernum) {
this.flyernum = flyernum;
}
public int getPoints() {
return points;
}
public void setPoints(int points) {
this.points = points;
}
@Override
public String toString() {
return "Passenger{" +
"name='" + name + '\'' +
", type='" + type + '\'' +
", seat='" + seat + '\'' +
", flyernum='" + flyernum + '\'' +
", points=" + points +
'}';
}
}
现在为了从文件中获取乘客的详细信息,我创建了GetPassengerDetails.class,它处理从CSV文件中读取数据并为每个乘客分配正确的值。
public class GetPassengerDetails{
/** Reads the file one line at a time. Each line will is that split up and translated into a Passenger object */
public List<Passenger> getPassengersFromFile(BufferedReader reader) throws IOException {
List<Passenger> passengers = new ArrayList<>();
String line;
while ((line = reader.readLine()) != null) {
String[] passengerDetails = line.trim().split(",");
Passenger passenger = new Passenger();
for (int i = 0; i < passengerDetails.length; i++) {
SetPassengerName(passengerDetails, passenger, i);
setPassengerFlightType(passengerDetails, passenger, i);
setPassengerSeatNumber(passengerDetails, passenger, i);
SetPassengerFlyerNumber(passengerDetails, passenger, i);
setPassengerPoints(passengerDetails, passenger, i);
}
passengers.add(passenger);
}
return passengers;
}
private void setPassengerPoints(String[] passengerDetails, Passenger passenger, int i) {
if(i< passengerDetails.length && i == 4) {
passenger.setPoints(Integer.parseInt(String.valueOf(passengerDetails[4])));
}
}
private void SetPassengerFlyerNumber(String[] passengerDetails, Passenger passenger, int i) {
if(i< passengerDetails.length && i == 3) {
passenger.setFlyernum(String.valueOf(passengerDetails[3]));
}
}
private void setPassengerSeatNumber(String[] passengerDetails, Passenger passenger, int i) {
if(i< passengerDetails.length && i == 2) {
passenger.setSeat(String.valueOf(passengerDetails[2]));
}
}
private void setPassengerFlightType(String[] passengerDetails, Passenger passenger, int i) {
if(i< passengerDetails.length && i == 1) {
passenger.setType(String.valueOf(passengerDetails[1]));
}
}
private void SetPassengerName(String[] passengerDetails, Passenger passenger, int i) {
if(i< passengerDetails.length & i == 0) {
passenger.setName(String.valueOf(passengerDetails[i]));
}
}
}
这是测试以上代码的主要方法:
public class Main {
public static void main(String[] args) throws IOException {
String fileName = "resources/passengers.csv";
BufferedReader reader = new BufferedReader(new FileReader(fileName));
GetPassengerDetails passengerDetails = new GetPassengerDetails();
List<Passenger> passengers = passengerDetails.getPassengersFromFile(reader);
// For Testing Purposes lets get the Passengers
for (Passenger passenger : passengers
) {
System.out.println(passenger.toString());
}
}
}
运行main方法后,将得到以下结果:
答案 1 :(得分:0)
使用此主要方法从文本文件中读取数据,并将数据聚合到Passengers对象中。旅客清单objec中的旅客的全部清单。
public static void main(String[] args) {
List<Passengers> passengersList = new ArrayList<Passengers>();
File file = new File("Your file location..");
try {
BufferedReader br = new BufferedReader(new FileReader(file));
String st;
while ((st = br.readLine()) != null){
String[] data = st.split(",");
String flyNumber = null;
int flyPoints = 0;
switch (data.length){
case 4: flyNumber = data[3];
break;
case 5: flyNumber = data[3];
flyPoints = Integer.valueOf(data[4]);
break;
}
Passengers passenger = new Passengers(data[0], data[1], data[2], flyNumber, flyPoints);
passengersList.add(passenger);
}
System.out.println(passengersList.get(0));
} catch (IOException e) {
e.printStackTrace();
}
}