java获取上周所有日期

业务上面有这个需求，所以直接拿过来了，来源是百度，感谢原作者

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

public class NewTest {
public static void main(String args[]) {
SimpleDateFormatsf = new SimpleDateFormat("yyyy-MM-dd");
Calendar cal = Calendar.getInstance();
System.out.println("=========LastWeek Days=========");
cal.add(Calendar.WEEK_OF_MONTH, -1);
for (int i = 0; i < 7; i++) {
cal.add(Calendar.DATE, -1 * cal.get(Calendar.DAY_OF_WEEK) + 2 + i);
System.out.println(sf.format(cal.getTime()));
}
System.out.println("=========ThisMonth Days=========");
cal = Calendar.getInstance();
cal.set(cal.get(Calendar.YEAR), cal.get(Calendar.MONTH), 1);
cal.add(Calendar.MONTH, 1);
cal.add(Calendar.DATE, -1);
String lastDay =sf.format(cal.getTime());
String aDay = "";
int i = 1;
while (!lastDay.equals(aDay)) {
cal.set(cal.get(Calendar.YEAR), cal.get(Calendar.MONTH), i);
aDay = sf.format(cal.getTime());
System.out.println(sf.format(cal.getTime()));
i++;
}
System.out.println("=========LastMonth Days=========");
cal = Calendar.getInstance();
cal.set(cal.get(Calendar.YEAR), cal.get(Calendar.MONTH), 1);
cal.add(Calendar.DATE, -1);
lastDay = sf.format(cal.getTime());
i = 1;
while (!lastDay.equals(aDay)) {
cal.set(cal.get(Calendar.YEAR), cal.get(Calendar.MONTH), i);
aDay = sf.format(cal.getTime());
System.out.println(sf.format(cal.getTime()));
i++;
}
}
}