本文为大家分享的都是常用的日期之间的比较方法，供以后参考。

热身：获取当前时间

SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");//设置日期格式
String nowDate = df.format(new Date());// new Date()为获取当前系统时间

注：楼主一直以为date类型不如string类型随心所欲，所以下面的比较都是string类型的date进行比较。如果你真的真的就是那么倔强，ok，下面是date转string的方法：

SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");//设置日期格式
String date = df.format(Date类型的时间);

1.两个string类型的日期比较大小

public static int compare_date(String DATE1, String DATE2) { DateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); try { Date dt1 = df.parse(DATE1); Date dt2 = df.parse(DATE2); if (dt1.getTime() > dt2.getTime()) { System.out.println("dt1 在dt2前"); return 1; } else if (dt1.getTime() < dt2.getTime()) { System.out.println("dt1在dt2后"); return -1; } else { return 0; } } catch (Exception exception) { exception.printStackTrace(); } return 0; }

2.返回两个string类型日期之间相差的天数

public static int daysBetween(String smdate,String bdate){ SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd"); Calendar cal = Calendar.getInstance(); long time1 = 0; long time2 = 0; try{ cal.setTime(sdf.parse(smdate)); time1 = cal.getTimeInMillis(); cal.setTime(sdf.parse(bdate)); time2 = cal.getTimeInMillis(); }catch(Exception e){ e.printStackTrace(); } long between_days=(time2-time1)/(1000*3600*24); return Integer.parseInt(String.valueOf(between_days)); }

3.返回两个string类型日期相差的小时数

public static int daysBetween2(String startTime, String endTime) { SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd HH"); Calendar cal = Calendar.getInstance(); long time1 = 0; long time2 = 0; try{ cal.setTime(sdf.parse(startTime)); time1 = cal.getTimeInMillis(); cal.setTime(sdf.parse(endTime)); time2 = cal.getTimeInMillis(); }catch(Exception e){ e.printStackTrace(); } long between_days=(time2-time1)/(1000*3600); return Integer.parseInt(String.valueOf(between_days)); }

4.计算两段日期的重合日期

/** * 计算两段日期的重合日期 * @param str1 开始日期1 * @param str2 结束日期1 * @param str3 开始日期2 * @param str4 结束日期2 * @return * @throws Exception */ public static Map<String,Object> comparisonRQ(String str1, String str2, String str3, String str4) throws Exception { String mesg = ""; DateFormat df = new SimpleDateFormat("yyyy-MM-dd"); String startdate = ""; String enddate = ""; try { Date dt1 = df.parse(str1); Date dt2 = df.parse(str2); Date dt3 = df.parse(str3); Date dt4 = df.parse(str4); if (dt1.getTime()<=dt3.getTime()&&dt3.getTime()<=dt2.getTime()&&dt2.getTime()<=dt4.getTime()) { mesg = "f";//重合 startdate = str3; enddate = str2; } if (dt1.getTime()>=dt3.getTime()&&dt3.getTime()<=dt2.getTime()&&dt2.getTime()<=dt4.getTime()) { mesg = "f";//重合 startdate = str1; enddate = str2; } if (dt3.getTime()<=dt1.getTime()&&dt1.getTime()<=dt4.getTime()&&dt4.getTime()<=dt2.getTime()) { mesg = "f";//重合 startdate = str1; enddate = str4; } if (dt3.getTime()>=dt1.getTime()&&dt1.getTime()<=dt4.getTime()&&dt4.getTime()<=dt2.getTime()) { mesg = "f";//重合 startdate = str3; enddate = str4; } System.out.println(startdate+"----"+enddate); }catch (ParseException e) { e.printStackTrace(); throw new ParseException(e.getMessage(), 0); }catch(Exception e){ e.printStackTrace(); throw new Exception(e); } Map<String,Object> map = new HashMap<String,Object>(); map.put("startdate", startdate); map.put("enddate", enddate); return map; }

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。