0129 JAVA 第三课 分支、循环、例外

作业：

1. 分支语句：if-else,break,switch,return;
2. 循环语句：while,do-while,for,continue;
3. 例外处理语句：try-catch-finally,throw;
4. 数组-二维数组，Java中列表的使用
5. 列表使用 区分set和List的区别
   输出星期一到星期日的英文单词，几种不同的实现。

技能学习-如果能和实际情况联系起来，就可以做到学以致用，使用一次后，才会有第二次使用，才会有举一反三。

//if-else
  public void printWeek(int day) {
        int i = 0;
        i = day % 7;
        if (i < 6) {
            System.out.println("今天是：" + week[i] + ",是个工作日");
        } else {
            System.out.println("今天是：" + week[i] + ",是个休息日");
        }
    }

//switch-case
    public void printForWeek(int day) {

        switch (day) {
        case 1:
            System.out.println("printForWeek今天是：" + week[0] + ",是个工作日");
            break;
        case 2:
            System.out.println("printForWeek今天是：" + week[1] + ",是个工作日");
            break;
        case 3:
            System.out.println("printForWeek今天是：" + week[2] + ",是个工作日");
            break;
        case 4:
            System.out.println("printForWeek今天是：" + week[3] + ",是个工作日");
            break;
        case 5:
            System.out.println("printForWeek今天是：" + week[4] + ",是个工作日");
            break;
        case 6:
            System.out.println("printForWeek今天是：" + week[5] + ",是个休息日");
            break;
        case 7:
            System.out.println("printForWeek今天是：" + week[6] + ",是个休息日");
            break;
        default:
            System.out.println("printForWeek请输入1-7的数字");
        }
    }
//while
    public void printForWeekWhile() {
        int i = 0;
        while (i < week.length) {
            System.out.println("printForWeekWhile今天是：" + week[i] + "");
            i++;
        }
    }
//do-while
    public void printForWeekDo() {
        int i = week.length;
        do {
            System.out.println("printForWeekDo今天是：" + week[i - 1] + "");
            i--;
        }
        while (i > 0);
    }

//打印二维数组,第一个纬度是数组，第二个纬度是定义一种数据结构
//网上的例子，比如 {zhangsan，男，23岁}，{李四，男，24岁}
       public void printFowWeekS() {
        String weeks[][] = {{"Mon","1","星期一"},
                        {"Tue","2","星期二"},
                        {"Wed","3","星期三"}, 
                        {"Thu","4","星期四"},
                        {"Fri","5","星期五"},
                        {"Sat","6","星期六"},
                        {"Sun","7","星期日"}};
        for (int i = 0; i < weeks.length; i++) {
            System.out.println("printFowWeekS数组：" + i);
            for (int j = 0; j < weeks[i].length; j++) {
                System.out.print(" " + weeks[i][j] + " ");
            }
            System.out.println();
        }
    }
//根据日期打印星期几
    public int dayForWeek(String pTime) throws Exception {
        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
        Calendar c = Calendar.getInstance();
        c.setTime(format.parse(pTime));
        int dayForWeek = 0;
        if (c.get(Calendar.DAY_OF_WEEK) == 1) {
            dayForWeek = 7;
        } else {
            dayForWeek = c.get(Calendar.DAY_OF_WEEK) - 1;
        }
        return dayForWeek;
    }

//验证
    public static void main(String[] args) {
        int week = 0;
        Logic logic = new Logic();
        logic.printWeek(2);
        logic.printWeek(3);
        logic.printWeek(6);
        try {
            week = logic.dayForWeek("2016-01-31");
            System.out.println("今天星期" + week);
            week = logic.dayForWeek("2016-02-01");
            System.out.println("今天星期" + week);
            week = logic.dayForWeek("eee");
        }
        catch (Exception e) {
            System.out.println("日期格式不对");
            e.printStackTrace();

        }finally{
             System.out.println("始终都会执行的语句");
        }
        logic.printForWeek(6);
        logic.printForWeek(8);
        logic.printForWeekWhile();
        logic.printForWeekDo();
        logic.printFowWeekS();
    }

结果
今天是：Wed,是个工作日
今天是：Thu,是个工作日
今天是：Sun,是个休息日
今天星期7
今天星期1
日期格式不对
java.text.ParseException: Unparseable date: "eee"
    at java.text.DateFormat.parse(Unknown Source)
    at pers.qingqian.study.basic.Logic.dayForWeek(Logic.java:82)
    at pers.qingqian.study.basic.Logic.main(Logic.java:47)
始终都会执行的语句
printForWeek今天是：Sat,是个休息日
printForWeek请输入1-7的数字
printForWeekWhile今天是：Mon
printForWeekWhile今天是：Tue
printForWeekWhile今天是：Wed
printForWeekWhile今天是：Thu
printForWeekWhile今天是：Fri
printForWeekWhile今天是：Sat
printForWeekWhile今天是：Sun
printForWeekDo今天是：Sun
printForWeekDo今天是：Sat
printForWeekDo今天是：Fri
printForWeekDo今天是：Thu
printForWeekDo今天是：Wed
printForWeekDo今天是：Tue
printForWeekDo今天是：Mon
printFowWeekS数组：0
 Mon  1  星期一 
printFowWeekS数组：1
 Tue  2  星期二 
printFowWeekS数组：2
 Wed  3  星期三 
printFowWeekS数组：3
 Thu  4  星期四 
printFowWeekS数组：4
 Fri  5  星期五 
printFowWeekS数组：5
 Sat  6  星期六 
printFowWeekS数组：6
 Sun  7  星期日