java对指定时间进行年月日小时控制

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
public class Try {
 
    public static void main(String[] args) throws ParseException {
        String time="2016-08-12 15:22";//设置时间
        String hourTime,dayTime,monthTime,yearTime;
        Calendar c = Calendar.getInstance();
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm");
        Date e;
        e = sdf.parse(time);
        c.setTime(e);
      System.out.println(c.get(Calendar.HOUR_OF_DAY)+":"+c.get(Calendar.MINUTE)+"/"+c.get(Calendar.MONTH));//获得时,分,月(0为1月)
        int d=(c.get(Calendar.HOUR_OF_DAY)*60+c.get(Calendar.MINUTE))/5;//多少个5分钟
        if (c.get(Calendar.HOUR_OF_DAY) >= 12) {
            c.set(Calendar.MINUTE, 0);
            c.set(Calendar.SECOND, 0);
            c.add(Calendar.HOUR_OF_DAY,0);//-1取之前一个小时整点，0取当前一个小时整点，以此类推.
            hourTime = dateToString(c.getTime(),
                    "yyyy-MM-dd HH:mm:ss");
 
        } else {
            c.set(Calendar.MINUTE, 0);
            c.set(Calendar.SECOND, 0);
            c.add(Calendar.HOUR_OF_DAY,0);//-1取之前一个小时整点，0取当前一个小时整点，以此类推
            hourTime = dateToString(c.getTime(),
                    "yyyy-MM-dd HH:mm:ss");
        }
       
         System.out.println(hourTime+"//"+d);
         if (c.get(Calendar.HOUR_OF_DAY) >= 12) {
                c.set(Calendar.MINUTE, 0);
                c.set(Calendar.SECOND, 0);
                c.set(Calendar.DAY_OF_MONTH,1);//0取上一个月最后一天 1取这个月第一天，以此类推.
                dayTime = dateToString(c.getTime(),
                        "yyyy-MM-dd HH:mm:ss");
 
            } else {
                c.set(Calendar.MINUTE, 0);
                c.set(Calendar.SECOND, 0);
                c.set(Calendar.DAY_OF_MONTH,1);//0取上一个月最后一天 1取这个月第一天，以此类推.
                dayTime = dateToString(c.getTime(),
                        "yyyy-MM-dd HH:mm:ss");
            }
         System.out.println(dayTime+"//");
         
         if (c.get(Calendar.HOUR_OF_DAY) >= 12) {
                c.set(Calendar.MINUTE, 0);
                c.set(Calendar.SECOND, 0);
                c.set(Calendar.DAY_OF_MONTH,1);
                c.set(Calendar.MONTH,0);//在控制天数的情况下,进行控制月份，0为1月， 1为2月 ，以此类推
                monthTime = dateToString(c.getTime(),
                        "yyyy-MM-dd HH:mm:ss");
 
            } else {
                c.set(Calendar.MINUTE, 0);
                c.set(Calendar.SECOND, 0);
                c.set(Calendar.DAY_OF_MONTH,1);
                c.set(Calendar.MONTH,0);//在控制天数的情况下,进行控制月份，0为1月， 1为2月， 以此类推
                monthTime = dateToString(c.getTime(),
                        "yyyy-MM-dd HH:mm:ss");
            }
         System.out.println(monthTime+"//");
         if (c.get(Calendar.HOUR_OF_DAY) >= 12) {
                c.set(Calendar.MINUTE, 0);
                c.set(Calendar.SECOND, 0);
                c.set(Calendar.DAY_OF_MONTH,1);
                c.add(Calendar.YEAR,1);//在控制天数的情况下,进行控制月份，0为今年， 1为加一年 ，以此类推
                yearTime = dateToString(c.getTime(),
                        "yyyy-MM-dd HH:mm:ss");
 
            } else {
                c.set(Calendar.MINUTE, 0);
                c.set(Calendar.SECOND, 0);
                c.set(Calendar.DAY_OF_MONTH,1);
                c.add(Calendar.YEAR,1);//在控制天数的情况下,进行控制月份，0为今年， 1为加一年 ，以此类推
                yearTime = dateToString(c.getTime(),
                        "yyyy-MM-dd HH:mm:ss");
            }
         System.out.println(yearTime+"//");
    }
    public static String dateToString(Date date, String formatString) {
        if (formatString == null || formatString.equals(""))
            formatString = "yyyy-MM-dd HH:mm:ss";
        try {
            SimpleDateFormat sdf = new SimpleDateFormat(formatString);
            return sdf.format(date);
        } catch (Exception e) {
            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
            return sdf.format(date);
        }
    }
    public static Date stringToDate(String strDate, Date defaultValue) {
        return stringToDate(strDate, "yyyy-MM-dd HH:mm:ss", defaultValue);
    }
    public static Date stringToDate(String strDate, String formatString,
            Date defaultValue) {
        if (formatString == null || formatString.equals(""))
            formatString = "yyyy-MM-dd HH:mm:ss";
        try {
            SimpleDateFormat sdf = new SimpleDateFormat(formatString);
            return sdf.parse(strDate);
        } catch (Exception e) {
            return defaultValue;
        }
    }
 
}```