获取每周的周一

public String getMonday(){
    SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd");//设置日期格式
    Calendar cld = Calendar.getInstance(Locale.CHINA);
    cld.setFirstDayOfWeek(Calendar.MONDAY);//以周一为首日
    cld.setTimeInMillis(System.currentTimeMillis());//当前时间

    cld.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);//周一
    System.out.println(df.format(cld.getTime()));
    return df.format(cld.getTime()).replaceAll("-","");
}