Question

Java 输入一个年份获得一年的所有星期四的日期 打印日期即可

Answer 1

public void testSearchDate(){//日期查询
 
 int year = 2013;//定义一个字段，接收输入的年份
 Calendar calendar = new GregorianCalendar();//定义一个日历，变量作为年初
 Calendar calendarEnd = new GregorianCalendar();//定义一个日历，变量作为年末
 calendar.set(Calendar.YEAR, year);
 calendar.set(Calendar.MONTH, 0);
 calendar.set(Calendar.DAY_OF_MONTH, 1);//设置年初的日期为1月1日
 calendarEnd.set(Calendar.YEAR, year);
 calendarEnd.set(Calendar.MONTH, 11);
 calendarEnd.set(Calendar.DAY_OF_MONTH, 31);//设置年末的日期为12月31日
 
 SimpleDateFormat sf = new SimpleDateFormat("yyyy-MM-dd");
 
 while(calendar.getTime().getTime()<=calendarEnd.getTime().getTime()){//用一整年的日期循环
  if(calendar.get(Calendar.DAY_OF_WEEK)==5){//判断如果为星期四时，打印
   System.out.println(sf.format(calendar.getTime()));
  }
  calendar.add(Calendar.DAY_OF_MONTH, 1);//日期+1
 }
}

看能不能达到你想要的效果

Answer 2

 public static void main(String[]args) {

        int year = 2013;
        Calendar calendar = Calendar.getInstance();
        calendar.set(Calendar.YEAR,year);
        calendar.set(Calendar.MONTH,11);

        int allWeek =  calendar.get(Calendar.WEEK_OF_YEAR);

        for(int i= 1; i <= allWeek ; i++ ){
            System.out.println(fmtDate(getThursdayOfWeek(calendar.getTime(),i),""));
        }

    }

    public static String fmtDate(Date date,String fmt){
        if(date==null) return null;
        SimpleDateFormat sdf = new SimpleDateFormat((fmt!=null && !"".equals(fmt)) ? fmt : "yyyy-MM-dd");
        return sdf.format(date);
    }


    public static Date getThursdayOfWeek(Date year, int week) {
        Calendar c = Calendar.getInstance();
        c.setTime(year);
        c.set(Calendar.WEEK_OF_YEAR, week);
        c.set(Calendar.DAY_OF_WEEK, Calendar.THURSDAY);
        return c.getTime();
    }
    
    感觉好像还有点问题 我再修改一下

Answer 3

public static void main(String[] args) {

Scanner sc = new Scanner(System.in);
System.out.println("输入年份：");
String input = sc.nextLine();
try {
int year = Integer.parseInt(input);
Calendar c = Calendar.getInstance();
c.clear();
//设置年份
c.set (Calendar.YEAR, year);
//设置星期四
c.set(Calendar.DAY_OF_WEEK, 5);
while(true){
if(c.get(Calendar.YEAR)!=year){
break;
}
System.out.println(c.getTime());
//增加1星期
c.add(Calendar.DAY_OF_WEEK, c.getMaximum(Calendar.DAY_OF_WEEK));
}
} catch (Exception e) {
System.out.println("输入有误！");
}

}

Answer 4

用Calendar API,整体思路是先找到第一个星期四，之后每隔7天取出日期

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;

public class CalendarTest {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
PrintTuesday("2014");
}

public static void PrintTuesday(String year){ /*找到第一个星期四*/

String tempdate = year+"-01-01"; //先取第一天的值
SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");
Calendar cal = Calendar.getInstance();
try {
cal.setTime(formatter.parse(tempdate));
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
if(cal.get(Calendar.DAY_OF_WEEK) == 5){ //如果第1天就是星期四，就直接调用全年星期四函数
PrintYearTuesday(cal);
}
else{
for(int i =0;i<7;i++){ //否则循环看看接下来7天内肯定有1天是星期四
cal.add(Calendar.DAY_OF_YEAR,1 );
if(cal.get(Calendar.DAY_OF_WEEK) == 5){
PrintYearTuesday(cal); //找到星期四后调用全年星期四函数
break; //找到后跳出，后面的循环无意义
}
}
}

}
public static void PrintYearTuesday(Calendar cal){ /*打印全年所有星期四*/
int tempyear = cal.get(Calendar.YEAR);
while(cal.get(Calendar.YEAR) == tempyear){

System.out.println(cal.get(Calendar.YEAR)+"-"+(cal.get(Calendar.MONTH)+1)+"-"+cal.get(Calendar.DAY_OF_MONTH));
cal.add(Calendar.DAY_OF_YEAR,7); //下个星期四肯定在7天后

}
}
}