main.java

java的经典例子

import java.util.Date;
import java.util.Vector;
import java.io.IOException;
import java.io.DataInputStream;

class Main {
    private final static Vector monthVec = new Vector(12);
    static {
        String[] months = {
            "Jan", "Feb", "Mar", "Apr", "May", "Jun",
            "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
        for (int i = 0; i < months.length; i++)
            monthVec.addElement(months[i]);
    }
    public static int readFromUser(String query, Vector map) {
        System.out.print("Enter " + query + ": ");
        System.out.flush();
        try {
            DataInputStream in = new DataInputStream(System.in);
            String numStr = in.readLine();
            return (map.indexOf(numStr));
        } catch (IOException e) {
        }
        return (0);
    }
    public static int readFromUser(String query) {
        System.out.print("Enter " + query + ": ");
        System.out.flush();
        try {
            DataInputStream in = new DataInputStream(System.in);
            String numStr = in.readLine();
            return (Integer.parseInt(numStr));
        } catch (IOException e) {
            return (0);
        } catch (NumberFormatException e) {
            return (0);
        }
    }
    private final static String[] fortunes = {
        "There is good prospect in store for you",
        "Don't travel aboard",
        "A mysterious stranger is in your future"
    };
    public static String getFortune(Date d) {
        // use birth date to determine fortune
        int days = (int)(d.getTime()/(24*60*60*1000));
        return (fortunes[days%fortunes.length]);
    }
    // Gets birth date from user and tells him his fortune
    public static void FortuneTeller(Date bday) {
        int year = readFromUser("Year");
        if (year > 1900)
            year -= 1900;
        int month = readFromUser("Month", monthVec);
        if (month < 0)
            month = 0;  // ignore
        int day = readFromUser("Day");

        // Set birth date
        bday.setYear(year);
        bday.setMonth(month);
        bday.setDate(day);
        System.out.println("Your fortune is: " + getFortune(bday) + ".");
    }
    public static void main(String[] args) {
        Date d = new Date();
        while (true)
            FortuneTeller(d);
    }
}