Java 展示星期的一个算法

Java 显示星期的一个算法
比如：总天数是num,num不定的，假设num=6，今天是周二，我需要在一向列表上这样显示

 周四，周五，周六，周日，昨天，今天

package com.demo; import java.util.Calendar; public class MainDemo { private static final String[] WEEKS = new String[]{"周日","周一","周二","周三","周四","周五","周六"}; /** * @param args */ public static void main(String[] args) { MainDemo mainDemo = new MainDemo(); mainDemo.print(9); } public void print(int num){ StringBuffer sb = new StringBuffer(); Calendar calendar = Calendar.getInstance(); int iCurrentWeek = calendar.get(Calendar.DAY_OF_WEEK); if(num > 0){ for(int i = 0;i < num;i++){ if(i < num - 2){ if(iCurrentWeek - (num - i) >= 0){ sb.append(WEEKS[iCurrentWeek - (num - i)] + "\t"); }else{ sb.append(WEEKS[iCurrentWeek - (num - i) + WEEKS.length] + "\t"); } }else{ if(i == num - 2){ sb.append("昨天\t"); }else if(i == num - 1){ sb.append("今天\t"); } } } } System.out.println(sb.toString().trim()); } }