Java 使用DateTimeFormatter正确调整时间

我正在创建一个约会应用程序，它可以每月/每周查看。标准视图能够以HH:mm显示正确的时间，仅在9:00到17:00之间。但是，每月/每周我无法转换并在24小时内显示

每月我有：

public LocalTime getTime() {
         return time;
}

    @FXML
private void viewByMonthHandler(ActionEvent event) {
    
    DataProvider.getAppointmentsByMonth().clear();
    DataProvider.getAppointmentsByWeek().clear();
    
    if(viewByMonthRadioButton.isSelected()) {
            // I was using these two to try and convert
            //DateTimeFormatter format = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm");
            //DateTimeFormatter timeFormat = DateTimeFormatter.ofPattern("MMMM HH:mm");

            Calendar cal = Calendar.getInstance();
            String month = new SimpleDateFormat("MMMM").format(cal.getTime());

        DataProvider.setMonthlyView(month);
    }      
    
    sortAppointment();
    viewByComboBox.setItems(viewByMonth);
    
}

    @FXML
private void viewByWeekHandler(ActionEvent event) {
    
    DataProvider.getAppointmentsByMonth().clear();
    DataProvider.getAppointmentsByWeek().clear();
    
    if(viewByWeekRadioButton.isSelected()) {
        
        DataProvider.setWeeklyView(0);
    }
    
    sortAppointment();
    viewByComboBox.setItems(viewByWeek);

}
       

我试过：

String month = new DateTimeFormatter.ofPattern("MMMM HH:mm").format(cal.getTime());

以及：

错误：

Caused by: java.lang.IllegalArgumentException: Cannot format given Object as a Date

就本周而言，我有：

public LocalTime getTime() {
         return time;
}

    @FXML
private void viewByMonthHandler(ActionEvent event) {
    
    DataProvider.getAppointmentsByMonth().clear();
    DataProvider.getAppointmentsByWeek().clear();
    
    if(viewByMonthRadioButton.isSelected()) {
            // I was using these two to try and convert
            //DateTimeFormatter format = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm");
            //DateTimeFormatter timeFormat = DateTimeFormatter.ofPattern("MMMM HH:mm");

            Calendar cal = Calendar.getInstance();
            String month = new SimpleDateFormat("MMMM").format(cal.getTime());

        DataProvider.setMonthlyView(month);
    }      
    
    sortAppointment();
    viewByComboBox.setItems(viewByMonth);
    
}

    @FXML
private void viewByWeekHandler(ActionEvent event) {
    
    DataProvider.getAppointmentsByMonth().clear();
    DataProvider.getAppointmentsByWeek().clear();
    
    if(viewByWeekRadioButton.isSelected()) {
        
        DataProvider.setWeeklyView(0);
    }
    
    sortAppointment();
    viewByComboBox.setItems(viewByWeek);

}
       

setWeeklyView：

    public static void setWeeklyView (int weekForReference) {
    
    try {
        
        ArrayList<Integer> selectedAppointmentsByWeek = new ArrayList<>();
        
        Statement statement = DBConnection.getConnection().createStatement();
        ResultSet weeklyAppointments = statement.executeQuery("SELECT appointmentId from appointment where year(start) = YEAR(date_add(curdate(), interval " + weekForReference + " WEEK)) and weekofyear(start) = weekofyear(date_add(curdate(),interval " + weekForReference + " WEEK));");
        
        while(weeklyAppointments.next()) {
            selectedAppointmentsByWeek.add(weeklyAppointments.getInt(1));
            
        }
        
        for(int appointmentId : selectedAppointmentsByWeek) {
            
            ResultSet selectAppointment = statement.executeQuery("SELECT customer.customerName, customer.customerId, contact, title, type, location, description, start, end FROM appointment JOIN customer ON customer.customerId = appointment.customerId WHERE appointmentId =" + appointmentId);
            selectAppointment.next();
           
            
            Appointment appointment = new Appointment();
            
            String customerName = selectAppointment.getString(1);
            int customerId = selectAppointment.getInt(2);
            String contact = selectAppointment.getString(3);
            String title = selectAppointment.getString(4);
            String type = selectAppointment.getString(5);
            String location = selectAppointment.getString(6);
            String description = selectAppointment.getString(7);
            String start = selectAppointment.getString(8);
            String end = selectAppointment.getString(9);
            
            appointment.setCustomerName(customerName);
            appointment.setContact(contact);
            appointment.setTitle(title);
            appointment.setType(type);
            appointment.setLocation(location);
            appointment.setDescription(description);
            appointment.setStart(start);
            appointment.setEnd(end);
            appointmentsByWeek.add(appointment);
            
        }
        
    }
    catch(SQLException ex) {
        System.out.println("Error " + ex.getMessage());
    }
    
}

publicstaticvoidsetweeklyview（intweekforreference）{
试一试{
ArrayList SelectedAppointsByWeek=新建ArrayList（）；
语句Statement=DBConnection.getConnection（）.createStatement（）；
ResultSet WeeklyAppoints=statement.executeQuery（“从约会中选择约会ID，其中年（开始）=年（日期添加（curdate（），间隔“+weekForReference+”周））和周（开始）=周（日期添加（curdate（），间隔“+weekForReference+”周））；
while（WeeklyAppoints.next（））{
SelectedAppointsByWeek.add（WeeklyAppoints.getInt（1））；
}
对于（内部任命ID:SelectedAppointsByWeek）{
结果设置selectAppointment=statement.executeQuery（“选择customer.customerName，customer.customerId，联系人，标题，类型，位置，描述，开始，结束从约会加入customer.customerId=appointment.customerId其中appointmentId=“+appointmentId”）；
选择appointment.next（）；
预约=新预约（）；
String customerName=selectAppointment.getString（1）；
int customerId=selectAppointment.getInt（2）；
String contact=selectAppointment.getString（3）；
String title=selectAppointment.getString（4）；
字符串类型=selectAppointment.getString（5）；
字符串位置=selectAppointment.getString（6）；
String description=selectAppointment.getString（7）；
String start=selectAppointment.getString（8）；
String end=selectAppointment.getString（9）；
预约。设置客户名称（客户名称）；
预约。设置联系人（联系人）；
任命.职称（职称）；
预约.设置类型（类型）；
预约。设置地点（地点）；
任命.说明（说明）；
预约。设置开始（开始）；
预约。结束（结束）；
任命周。添加（任命）；
}
}
catch（SQLException-ex）{
System.out.println（“错误”+ex.getMessage（））；
}
}

---

setMonthlyView几乎完全相同，只是将每周视图替换为每月视图。我如何格式化这些文件，使它们不再是HH:mm:ss.S，并且在9:00-17:00之间？我已经接受了之前给我的关于小部分的建议，但仍然无法理解。非常感谢您抽出时间阅读并提供帮助。

执行其中一项操作，随心所欲

12小时

String localDateTime12Hour =     
    LocalDateTime.now().format(DateTimeFormatter.ofPattern("MMMM hh:mm a"));
System.out.println(localDateTime12Hour);

24小时

String localDateTime24Hour =     
   LocalDateTime.now().format(DateTimeFormatter.ofPattern("MMMM HH:mm"));
System.out.println(localDateTime24Hour);

印刷品

July 06:11 PM
July 18:11

• 使用

  HH

  24小时
• 使用

  hh

  12小时（

  a

  提供AM或PM）

在指定格式化程序属性（如

MMMM

时，请记住使用

LocalDateTime

而不是

LocalTime

）。您正在

getTime（）

方法中返回一个

LocalTime

对象。我会避免使用

日历

和

日期

，因为它们已经过时了。使用包中的类