java 根据年 月 获取当前月每周日期区间

package comm.com.comm.utils;

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;

/**
* Created by dxr on 2017/6/14.
* 根据日期获取当前月的周区间
*/
public class DateUtils {
/**
* 调取方法
* @param year 年
* @param month 月
* @param weeks 第几周
* @return 返回第几周的开始与结束日期
*/
public static Map<String,Object> getScopeForweeks(int year,int month,int weeks){
Map<String,Object> map=new HashMap<String, Object>();
String time=year+"-"+getMonthToStr(month);
Map<String, Object> result = getDateScope(time);
//获取天数和周数
int resultDays=Integer.parseInt(result.get("days").toString());
int resultWeeks=Integer.parseInt(result.get("weeks").toString());
/**
* 如果参数周数大于实际周数
* 则返回一个不存在的日期
* 默认设置为当前 天数+1
*/
if(weeks>resultWeeks){
int days=resultDays+1;
String beginDate=year+"-"+getMonthToStr(month)+"-"+days;
map.put("beginDate",beginDate);
map.put("endDate",beginDate);
}else{
//获取当月第一天属于周几
Map<Integer, Object> scopes = getScope(time, resultDays, resultWeeks);
map=(Map<String,Object>)scopes.get(weeks);
}
return map;
}
/**
*获取某年某月的天数以及周数
* @param(格式：yyyy-MM)
* @return
*/
private static Map<String,Object> getDateScope(String time){
Map<String,Object> map=new HashMap<String, Object>();
try{
//保证日期位数
if(time.length()<=7){
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
Date date=sdf.parse(time+"-01");
Calendar c = Calendar.getInstance();
c.setTime(date);
//获取天数
int days = c.getActualMaximum(Calendar.DAY_OF_MONTH);
//获取周数
int weeks = c.getActualMaximum(Calendar.WEEK_OF_MONTH);
map.put("days",days);
map.put("weeks",weeks);
}else {
throw new RuntimeException("日期格式不正确");
}
}catch(Exception e){
e.printStackTrace();
}
return map;
}
/**
*获取本月周区间
* @param date(yyyy-mm)日期
* @param days 天数
* @param weeks 周数
* @return
*/
private static Map<Integer,Object> getScope(String date,int days,int weeks){
Map<Integer,Object> map=new HashMap<Integer, Object>();
//遍历周数
int midNum=0;
for(int i=1;i<=weeks;i++){
//第一周
if(i==1){
String time=date+"-01";
String week=getWeekOfDate(time);
//获取第一周还有多少天
int firstDays = getSurplusDays(week);
//获取第一周结束日期
int endDays=1+firstDays;
String time2=date+"-0"+endDays;
Map<String,Object> data=new HashMap<String, Object>();
data.put("beginDate",time);
data.put("endDate",time2);
map.put(i,data);
//
midNum=endDays;
}else{
//当前日期数+7 比较 当月天数
if((midNum+7)<=days){
int beginNum=midNum+1;
System.out.println("begin:"+beginNum);

int endNum=midNum+7;
System.out.println("end:"+endNum);

String time1=date+"-"+getNum(beginNum);
String time2=date+"-"+getNum(endNum);
Map<String,Object> data=new HashMap<String, Object>();
data.put("beginDate",time1);
data.put("endDate",time2);
map.put(i,data);
midNum=endNum;
}else{
int beginNum=midNum+1;
int endNum=days;
String time1=date+"-"+getNum(beginNum);
String time2=date+"-"+getNum(endNum);
Map<String,Object> data=new HashMap<String, Object>();
data.put("beginDate",time1);
data.put("endDate",time2);
map.put(i,data);
midNum=endNum;
}
}
}

return map;
}
/**
*获取日期属于周几
* @param time(格式：yyyy-MM-dd)
* @return
* @throws Exception
*/
private static String getWeekOfDate(String time){
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
String week="";
try{
Date date=sdf.parse(time);
String[] weekDays = {"星期日", "星期一", "星期二", "星期三", "星期四", "星期五", "星期六"};
Calendar cal = Calendar.getInstance();
cal.setTime(date);
int w = cal.get(Calendar.DAY_OF_WEEK) - 1;
if (w < 0)
w = 0;
week= weekDays[w];
}catch(Exception e){
e.printStackTrace();
}
return week;
}
/**
* 获取数字
* @return
*/
private static String getNum(int num){
int result=num/10;
if(result==0){
return "0"+num;
}else{
return num+"";
}
}
/**
* 返回月份的字符串
* @param month
* @return
*/
private static String getMonthToStr(int month){
String str="";
switch (month){
case 1:
str="01";
break;
case 2:
str="02";
break;
case 3:
str="03";
break;
case 4:
str="04";
break;
case 5:
str="05";
break;
case 6:
str="06";
break;
case 7:
str="07";
break;
case 8:
str="08";
break;
case 9:
str="09";
break;
case 10:
str="10";
break;
case 11:
str="11";
break;
case 12:
str="12";
break;
}
return str;
}
/**
* 根据当前周几判断当前周还有几天
* @param week{"星期日", "星期一", "星期二", "星期三", "星期四", "星期五", "星期六"}
* @return
*/
private static int getSurplusDays(String week){
int num=0;
if("星期日".equals(week)){
num=0;
}else if("星期一".equals(week)){
num=6;
}else if("星期二".equals(week)){
num=5;
}else if("星期三".equals(week)){
num=4;
}else if("星期四".equals(week)){
num=3;
}else if("星期五".equals(week)){
num=2;
}else if("星期六".equals(week)){
num=1;
}
return num;
}
/*public static void main(String[] args) {
Map<String, Object> map =DateUtils.getScopeForweeks(2017, 5, 5);
// Map<String, Object> map = getScopeForweeks(2017, 6, 6);
System.out.println(map.toString());
}*/
}