循环中的代码不会写入文本文件

Question

当我运行我的程序时，它会将 for 循环之外的元素写入文件，但是 for 循环中的内容不会写入文件。

public static void main(String[] args) {

    PrintWriter out;
    try {
        out = new PrintWriter("OUTPUT");
    } catch (FileNotFoundException e) {
        throw new RuntimeException(e);
    }

    out.write("Participant ID Date of Data Collection Time of Data Collection HR\n");

    for (Participant p : participants) {

            // Write the participant information to the OUTPUT file
            out.write(p.getID() + " " + p.getDate() + " " + p.getTime() + " " + " " +
                    p.getHR());
            }

        out.close();
    }
}

Answer 1

您的代码正在运行，但正如其他人提到的那样，参与者是空的，我宁愿在 try-catch 之间编写我的所有代码

public static void main(String[] args) {

        // This is only dummy data
        String date =  "2023/11/12";
        String timeStamp = "16:30";
        List<Participant> participants = List.of(
                new Participant(1,date, timeStamp, 20) ,
                new Participant(2,date, timeStamp, 20),
                new Participant(3,date, timeStamp, 20));

        try (PrintWriter out = new PrintWriter("OUTPUT")) {
            out.write("Participant ID Date of Data Collection Time of Data Collection HR\n");
            for (Participant p: participants) {
                // Write the participant information to the OUTPUT file
                out.write(p.getId() + " " + 
                          p.getDate() + " " + 
                          p.getTime() + " " + " " +
                          p.getHr() + '\n');
            }
        } catch (FileNotFoundException e) {
            throw new RuntimeException(e);
        }
    }
}


 class Participant {
    private int id;
    private String date;
    private String time;
    private int hr;

     public Participant(int id, String date, String time, int hr) {
         this.id = id;
         this.date = date;
         this.time = time;
         this.hr = hr;
     }

     public int getId() {
         return id;
     }

     public void setId(int id) {
         this.id = id;
     }

     public String getDate() {
         return date;
     }

     public void setDate(String date) {
         this.date = date;
     }

     public String getTime() {
         return time;
     }

     public void setTime(String time) {
         this.time = time;
     }

     public int getHr() {
         return hr;
     }

     public void setHr(int hr) {
         this.hr = hr;
     }
 }