java后台返回当前日期前30天的数据并排序

项目中遇到需要给前端返回30天的血糖数据，数据库中，只有当用户输入血糖才会有数据，所以后台需要把没有的数据补0。
思路是先使用工具类WeekUtil 获取当前日期的前30天日期，放在map中，键为时间，值为0，然后查出30天内的数据库的血糖记录list，遍历list,将数据放入到map中，然后将map中数据放入vo集合中，并按照对象属性createTime进行排序。
weekUtils代码如下：

   package com.wellness.platfront.common.util;import java.text.SimpleDateFormat;import java.util.ArrayList;import java.util.Calendar;import java.util.Date;import java.util.HashMap;import java.util.List;import java.util.Map;/** * 获取当天所在的一周的日期工具类 *  */public class WeekUtil {    private static WeekUtil instance = new WeekUtil();    private static SimpleDateFormat sdf  = new SimpleDateFormat("yyyy-MM-dd");      private WeekUtil(){}    public static WeekUtil getInstance(){        return instance;    }    /**     * 根据传入时间获取 该时间所在的一周的日期     * @param date 传入时间参数     * @return     */    public static Map<String,Date> weekDateOfToday(Date date){        Map<String,Date> weekMap = new HashMap<>();        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd 00:00:00");        Calendar calendar = Calendar.getInstance();        calendar.setTime(date);        try {            //周一            calendar.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);            Date mon = calendar.getTime();            //周二            calendar.set(Calendar.DAY_OF_WEEK, Calendar.TUESDAY);            Date tues = calendar.getTime();            //周三            calendar.set(Calendar.DAY_OF_WEEK, Calendar.WEDNESDAY);            Date wen = calendar.getTime();            //周四            calendar.set(Calendar.DAY_OF_WEEK, Calendar.THURSDAY);            Date thur = calendar.getTime();            //周五            calendar.set(Calendar.DAY_OF_WEEK, Calendar.FRIDAY);            Date fri = calendar.getTime();            //周六            calendar.set(Calendar.DAY_OF_WEEK, Calendar.SATURDAY);            String satday = simpleDateFormat.format(calendar.getTime());            Date sat = simpleDateFormat.parse(satday);            //周天            calendar.set(Calendar.DAY_OF_WEEK, Calendar.SUNDAY);            String sunday = simpleDateFormat.format(calendar.getTime());            Date sun = simpleDateFormat.parse(sunday);            weekMap.put("monday",mon);            weekMap.put("tuesday",tues);            weekMap.put("wednesday",wen);            weekMap.put("thursday",thur);            weekMap.put("friday",fri);            weekMap.put("saturday",sat);            weekMap.put("sunday",sun);        }catch (Exception e){            e.printStackTrace();        }        return weekMap;    }    /**     * 根据传入时间获取 该时间所在的一周的日期     * @param date 传入时间参数     * @return     */    public static List<String> weekDayOfToday(Date date){        List<String> weekList = new ArrayList<>();        Calendar calendar = Calendar.getInstance();        calendar.setTime(date);        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("d");        //周一        calendar.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);        String mon = simpleDateFormat.format(calendar.getTime());        //周二        calendar.set(Calendar.DAY_OF_WEEK, Calendar.TUESDAY);        String tues = simpleDateFormat.format(calendar.getTime());        //周三        calendar.set(Calendar.DAY_OF_WEEK, Calendar.WEDNESDAY);        String wen = simpleDateFormat.format(calendar.getTime());        //周四        calendar.set(Calendar.DAY_OF_WEEK, Calendar.THURSDAY);        String thur = simpleDateFormat.format(calendar.getTime());        //周五        calendar.set(Calendar.DAY_OF_WEEK, Calendar.FRIDAY);        String fri = simpleDateFormat.format(calendar.getTime());        //周六        calendar.set(Calendar.DAY_OF_WEEK, Calendar.SATURDAY);        String sat = simpleDateFormat.format(calendar.getTime());        //周天        calendar.set(Calendar.DAY_OF_WEEK, Calendar.SUNDAY);        String sun = simpleDateFormat.format(calendar.getTime());        weekList.add(sun);        weekList.add(mon);        weekList.add(tues);        weekList.add(wen);        weekList.add(thur);        weekList.add(fri);        weekList.add(sat);        return weekList;    }    /**     * 获取当前输入时间所在月份的所有 天     * @return     */    public static List<String> getDaysOfNowMonth(){        List<String> monthDayList = new ArrayList<>();        SimpleDateFormat format = new SimpleDateFormat("d");        Calendar ca = Calendar.getInstance();        ca.set(Calendar.DAY_OF_MONTH, ca.getActualMaximum(Calendar.DAY_OF_MONTH));        //获取当月最后一天        Integer last = Integer.parseInt(format.format(ca.getTime()));        for (int i = 1;i <= last;i++ ){            monthDayList.add(i+"");        }        return monthDayList;    }    /**     * 获取当前输入时间所在月份的所有日期     * @return     */    public static Map<String,Date> getDateOfNowMonth(){        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd 00:00:00");        Map<String,Date> dateMap = new HashMap<>();        Calendar ca = Calendar.getInstance();        ca.set(Calendar.DAY_OF_MONTH, ca.getActualMaximum(Calendar.DAY_OF_MONTH));        Calendar c = Calendar.getInstance();        c.add(Calendar.MONTH, 0);        c.set(Calendar.DAY_OF_MONTH,1);        try {            //第一天            String firstDateStr = simpleDateFormat.format(c.getTime());            Date firstDate = simpleDateFormat.parse(firstDateStr);            //最后一天            String lastDateStr = simpleDateFormat.format(ca.getTime());            Date lastDate = simpleDateFormat.parse(lastDateStr);            dateMap.put("firstDay",firstDate);            dateMap.put("lastDay",lastDate);        }catch (Exception e){            e.printStackTrace();        }        return dateMap;    }    /**     * 获取今日前number日的日期     * @param number     * @return     */    public static Date getDayFromToday(Integer number){        try {            Calendar c = Calendar.getInstance();            c.setTime(new Date());            c.add(c.DAY_OF_YEAR, -number);            SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd");            String date = simpleDateFormat.format(c.getTime());            return simpleDateFormat.parse(date);        }catch (Exception e){            e.printStackTrace();        }        return null;    }    /**     * 获取今日的日期     * @return     */    public static Date getDayToday(){        try {            Date date = new Date();            Calendar c = Calendar.getInstance();            c.setTime(date);            c.add(Calendar.DAY_OF_MONTH, 1);            SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd");            String dateStr = simpleDateFormat.format(c.getTime());            return simpleDateFormat.parse(dateStr);        }catch (Exception e){            e.printStackTrace();        }            return null;    }    public static List<String> getMonthDayList(){        List<String> dayList = new ArrayList<>();        dayList.add("7");        dayList.add("14");        dayList.add("21");        dayList.add("28");        return dayList;    }    /**     * 返回两个时间之间相差多少天     * @param now     * @param past     * @return     */    public static Integer dayNumberBetweenToDate(Date now , Date past){        try {            SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd");            String pastString = simpleDateFormat.format(past);            Date pastDate = simpleDateFormat.parse(pastString);            return (int)(((now.getTime() - pastDate.getTime() )/ (1000 * 3600 * 24)));        }catch (Exception e){            e.printStackTrace();        }        return null;    }    /**     * 获取当前日期前30天的日期(用于返回30天内血糖和血压)     */    public static Map<String, String> getDayMap(){        try {            Calendar calc =Calendar.getInstance();                Map<String, String> bloodMap = new HashMap<String, String>();             for(int i=0;i<30;i++){                     calc.setTime(new Date());                       calc.add(calc.DATE, -i);                       Date minDate = calc.getTime();                       bloodMap.put(sdf.format(minDate), "0");                  }               return bloodMap;        } catch (Exception e) {              e.printStackTrace();        }        return null;    } }

BloodGlucoseVo为返回给前端的vo：

package com.wellness.platfront.entity.healthCenter.vo;/** * 血糖的vo * @author  * @since 2017/09/26 */public class BloodGlucoseVo {    /**     * 血糖值     */    private String value;    /**     * 创建时间     */    private String createTime;    public String getValue() {        return value;    }    public void setValue(String value) {        this.value = value;    }    public String getCreateTime() {        return createTime;    }    public void setCreateTime(String createTime) {        this.createTime = createTime;    }}

service实现类中的方法：

package com.wellness.platfront.business.healthCenter.service.impl;import com.wellness.platfront.business.healthCenter.service.BloodGlucoseService;import com.wellness.platfront.business.healthCenter.validate.BloodValidate;import com.wellness.platfront.business.member.service.MemberService;import com.wellness.platfront.common.core.dao.primitive.HibernateDao;import com.wellness.platfront.common.core.service.impl.BasicServiceImpl;import com.wellness.platfront.common.exception.BasicRuntimeException;import com.wellness.platfront.common.util.WeekUtil;import com.wellness.platfront.entity.healthCenter.BloodGlucose;import com.wellness.platfront.entity.healthCenter.vo.BloodGlucoseVo;import com.wellness.platfront.entity.member.Member;import org.apache.commons.beanutils.BeanComparator;import org.apache.commons.collections.ComparatorUtils;import org.apache.commons.collections.comparators.ComparableComparator;import org.hibernate.Criteria;import org.hibernate.SessionFactory;import org.hibernate.criterion.Order;import org.hibernate.criterion.Restrictions;import org.springframework.stereotype.Service;import org.springframework.transaction.annotation.Transactional;import javassist.expr.NewArray;import javax.annotation.Resource;import java.text.DecimalFormat;import java.text.SimpleDateFormat;import java.util.*;/** * @author  * @version 创建时间：2017年5月31日 * 血糖接口实现类 */@Service("bloodGlucoseService")@Transactionalpublic class BloodGlucoseServiceImpl extends BasicServiceImpl<BloodGlucose, Integer>        implements BloodGlucoseService {    @Resource    private SessionFactory sessionFactory;    @Resource    private MemberService memberService;    Calendar calendar = Calendar.getInstance();    private HibernateDao<BloodGlucose, Integer> dao = new HibernateDao<>(sessionFactory,            BloodGlucose.class);    private SimpleDateFormat dateFormat = new SimpleDateFormat("YYYY-MM-dd");    /**     * 查询最近30天的血糖记录     */    @Override    public List<BloodGlucoseVo> getMonthBloodSugar(Integer memberId) {         try {         //定义排序规则    Comparator mycmp = ComparableComparator.getInstance();         //reversedComparator 为倒序排序，默认为正序，             mycmp = ComparatorUtils.reversedComparator(mycmp);    //如果要自定义的排序规则，需在bean的属性后加上，如果默认则不用加，"createTime"为集合对象中的属性             BeanComparator bc = new BeanComparator("createTime",mycmp);             List<BloodGlucoseVo> list = new ArrayList<>();                calendar.setTime(new Date());                calendar.add(Calendar.DATE, -30);                Date firstDate = calendar.getTime();                Criteria criteria = dao.createCriteria();                criteria.add(Restrictions.eq("member.memberId", memberId));                criteria.add(Restrictions.ge("createTime", firstDate));                criteria.add(Restrictions.le("createTime", new Date()));                criteria.addOrder(Order.desc("createTime"));                List<BloodGlucose> bloodGlucoses = criteria.list();                //获取30天的日期集合                Map<String, String> dayMap = WeekUtil.getDayMap();                if (bloodGlucoses.size()>0) {                    BloodGlucoseVo bloodGlucoseVo;                    //将数据库查询的list集合数据放入map中                    for (int j = 0; j < bloodGlucoses.size(); j++) {                        //需要将时间格式化成与map返回的时间一样格式  yyyy-MM-dd 并将时间和血糖值放入map中覆盖原来的value                        dayMap.put(dateFormat.format(bloodGlucoses.get(j).getCreateTime()), bloodGlucoses.get(j).getValue());                    }                    //将map中的数据放入对应list中                    for (String day : dayMap.keySet()) {                        bloodGlucoseVo = new BloodGlucoseVo();                        bloodGlucoseVo.setValue(dayMap.get(day));                        bloodGlucoseVo.setCreateTime(day);                        list.add(bloodGlucoseVo);                        bloodGlucoseVo = null;                    }                    //将返回数据的list按照时间排序                    Collections.sort(list, bc);                }                return list;            } catch (Exception e) {                log.error(e.getMessage());                throw new BasicRuntimeException(this, "获取最近三十天的血糖记录异常" + e.getMessage());            }    }}