将 12 小时转换为 24 小时

Question

如何将12小时hh:mm a换算成HH:mm？当我们转换它时，我们无法进入 24 小时格式。当我们指定晚上 10 点开始时间和早上 7 点起床时间时，这里的时间格式 pm 到 am 没有转换。在这里我们无法获得总时间。它在 12:00am 停止，而且我们将从晚上 10 点到早上 7 点的总时间加倍为 18 小时。当时间从 11:59pm 变为 00:00am "00:00am" 时，问题就在这里。

public class Wakeup extends Activity {
ImageButton home, back, up_arw2, up_arw1, up_arw3, down_arw4, down_arw5, down_arw6;
TextView hours, minutes, ampm;
Button save_btn;
SharedPreferences timepreference;
SharedPreferences.Editor edittime;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.wakeup_time);
    hours = (TextView) findViewById(R.id.hours);
    minutes = (TextView) findViewById(R.id.minutes);
    ampm = (TextView) findViewById(R.id.ampm);
    home = (ImageButton) findViewById(R.id.home);
    save_btn = (Button) findViewById(R.id.save_btn);
    timepreference = getSharedPreferences("CHILDTIME", MODE_PRIVATE);
    Calendar c = Calendar.getInstance();
    SimpleDateFormat df = new SimpleDateFormat("HH:mm a");
    String formattedTime = df.format(c.getTime());
edittime = timepreference.edit();
    home.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            startActivity(new Intent(getApplicationContext(), Settings.class));
        }
    });

    back = (ImageButton) findViewById(R.id.back);
    back.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            startActivity(new Intent(getApplicationContext(), Settings.class));
        }
    });
    up_arw2 = (ImageButton) findViewById(R.id.up_arw2);
    up_arw2.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            int timenum = Integer.parseInt(hours.getText().toString());
            if (timenum == 11) {
                if (ampm.getText().toString().equals("AM")) {
                    ampm.setText("PM");
                    timenum++;
                    hours.setText(String.valueOf(timenum));
                } else {
                    ampm.setText("AM");
                    timenum++;
                    hours.setText(String.valueOf(timenum));
                }
            } else {
                timenum++;
                hours.setText(String.valueOf(timenum));
                down_arw4.setClickable(true);
            }
            if (timenum > 12) {
                hours.setText("1");
            }
        }
    });
    down_arw4 = (ImageButton) findViewById(R.id.down_arw4);
    down_arw4.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            int timenum = Integer.parseInt(hours.getText().toString());
            if (timenum == 1) {
                hours.setText("12");
            } else {
                timenum--;
                hours.setText(String.valueOf(timenum));
            }
        }
    });
    up_arw3 = (ImageButton) findViewById(R.id.up_arw3);
    up_arw3.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            int timenum = Integer.parseInt(minutes.getText().toString());
            if (timenum == 59) {
                minutes.setText("00");
            } else {
                timenum++;
                minutes.setText(roundedmin(String.valueOf(timenum)));
            }
        }
    });
    down_arw5 = (ImageButton) findViewById(R.id.down_arw5);
    down_arw5.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            int timenum = Integer.parseInt(minutes.getText().toString());
            if (timenum == 0) {
                minutes.setText("59");
            } else {
                timenum--;
                minutes.setText(roundedmin(String.valueOf(timenum)));
                up_arw3.setClickable(true);
            }
        }
    });
    down_arw6 = (ImageButton) findViewById(R.id.down_arw6);
    down_arw6.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            ampm.setText("PM");
        }
    });
    up_arw1 = (ImageButton) findViewById(R.id.up_arw1);
    up_arw1.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            ampm.setText("AM");
        }
    });

    save_btn.setOnClickListener(new View.OnClickListener() {
        Date date;
        long gottimesss,millisecndslong;
        @Override
        public void onClick(View v) {
            SimpleDateFormat displayFormat = new SimpleDateFormat("HH:mm");
            SimpleDateFormat parseFormat = new SimpleDateFormat("hh:mm a");
            try {
                date = parseFormat.parse(hours.getText().toString() + ":" + minutes.getText().toString() + " " + ampm.getText().toString());
                String gottime = displayFormat.format(date);
                String[] timedivided = gottime.split(":");
                String gothr = timedivided[0];
                long gotlong = TimeUnit.HOURS.toMinutes(Long.parseLong(gothr));
                String gotmin = timedivided[1];
                int gotintmin = Integer.parseInt(gotmin);
                gottimesss=gotlong+gotintmin;
                millisecndslong=TimeUnit.MINUTES.toMillis(gottimesss);
                convertSecToHoursMinute(millisecndslong);
                Log.d("GOtssss", String.valueOf(millisecndslong));
                Log.d("timing", "");
            } catch (ParseException e) {
                e.printStackTrace();
            }
 edittime.putLong("savedwakeuptime", millisecndslong);
edittime.commit();
startActivity(new Intent(getApplicationContext(), Home.class));
        }
    });
}
String convertSecToHoursMinute(long Sec) {
    long hours = Sec / 3600;
    long minutes = (Sec % 3600) / 60;
    long seconds = (Sec % 3600) % 60;

    String amPm = "am";
    if (minutes == 60) {
        minutes = 0;
        hours = hours + 1;
    }
    if (hours == 12) {
        amPm = "pm";
    }
    if (hours == 0) {
        hours = 12;
    }
    if (hours > 12) {
        hours = hours - 12;
        amPm = "pm";
    }
    Log.d("Timingdata",setZeroBeforeNine(hours) + ":" + setZeroBeforeNine(minutes) + " " + amPm);
    return setZeroBeforeNine(hours) + ":" + setZeroBeforeNine(minutes) + " " + amPm;
}

public static String setZeroBeforeNine(long digit) {
    try {
        if (digit <= 9) {
            return "0" + digit;
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
    return "" + digit;
}

public static String roundedmin(String min) {
    if (min.length() == 1) {
        min = "0" + min;
    }
    return min;
}
}

Answer 1

试试这个代码

import java.text.SimpleDateFormat;
import java.util.Date;

    public class Main {
       public static void main(String [] args) throws Exception {
           SimpleDateFormat displayFormat = new SimpleDateFormat("HH:mm");
           SimpleDateFormat parseFormat = new SimpleDateFormat("hh:mm a");
           Date date = parseFormat.parse("10:30 PM");
           System.out.println(parseFormat.format(date) + " = " + displayFormat.format(date));
       }
}

Answer 2

使用这两种方法将秒格式转换为 24 小时格式 public 静态

String convertSecToHoursMinute(long Sec) {
        long hours = Sec / 3600;
        long minutes = (Sec % 3600) / 60;
        long seconds = (Sec % 3600) % 60;
        String amPm = "am";
        if (minutes == 60) {
            minutes = 0;
            hours = hours + 1;
        }


        if (hours == 12) {
            amPm = "pm";
        }
        if (hours == 0) {
            hours = 12;
        }
        if (hours > 12) {
            hours = hours - 12;
            amPm = "pm";
        }
        return setZeroBeforeNine(hours) + ":" + setZeroBeforeNine(minutes) + " " + amPm;
    }

    /**
     * To set Zero before digits if less than 9(for date and time)
     *
     * @param digit : Date and time before which 0 is placed if less than 9
     * @return :return Digit placing 0 as prefix if digit is less than 9
     */
    public static String setZeroBeforeNine(long digit) {
        try {
            if (digit <= 9) {
                return "0" + digit;
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return "" + digit;
    }

将 12 小时转换为 24 小时

Convert 12 hours to 24 hours

java

time

android

simpledateformat