第一单元：（吃货联盟订餐系统项目案例）

package learn;

import java.util.Scanner;

public class Ordering {
	public static void main(String[] args) {
		String[] names = new String[4];// 保存订餐人姓名
		String[] dishMegs = new String[4];//e 保存所选信息，包括菜品名及份数
		int[] times = new int[4];// 保存送餐时间
		String[] addresses = new String[4];// 保存送餐地址
		int[] states = new int[4];// 保存订单状态：0表示已预定，1表示已完成
		double[] sumPrices = new double[4];// 保存订单总额
		String[] dishNames = { "红烧带鱼", "鱼香肉丝", "时令鲜蔬" };// 菜品名称
		double[] prices = new double[] { 30.8, 20.0, 10.0, };// 菜品单价
		int[] praiseNums = new int[3];// 点赞数
		System.out.println("\t\t欢迎使用吃货联盟订餐系统");
		Scanner input = new Scanner(System.in);
		int num = -1;
		boolean isExit = false;
		do {
			System.out.println("********************************************");
			System.out.println("1、我要订餐" + "\n2、查看餐袋" + "\n3、签收订单" + "\n4、删除订单" + "\n5、我要点赞" + "\n6、退出系统");
			System.out.println("********************************************");
			System.out.print("请选择:");
			int choice = input.nextInt();
			switch (choice) {
			case 1:
				System.out.println("********1.我要订餐********");
				boolean isAdd = false;
				for (int i = 0; i < names.length; i++) {
					if (names[i] == null) {
						isAdd = true;
						System.out.print("请输入订餐人姓名:");
						String name = input.next();
						System.out.println("序号\t" + "菜名\t" + "单价\t" + "点赞数");
						for (int j = 0; j < dishNames.length; j++) {
							String price = prices[j] + "元";
							String praiseNum = (praiseNums[j]) > 0 ? praiseNums[j] + "赞" : "0";
							System.out.println((j + 1) + "\t" + dishNames[j] + "\t" + price + "\t" + praiseNum);
						}
						System.out.print("请选择您需要的菜品编号:");
						int serial=input.nextInt();
						System.out.print("请选择你需要的份数:");
						int portion=input.nextInt();
						String dishMeg= dishNames[serial-1]+" "+portion+"份";
						double canfei=prices[serial-1]*portion;
						double charge=(canfei>=50)?0:5;
						System.out.print("请输入送餐时间:（时间是10点至20点整送餐）");
						int time = input.nextInt();
						while (time<10 || time>20) {
							System.out.print("您输入的有误请输入10到20点之间的整数");
								time=input.nextInt();
						}
						System.out.print("请输入送餐地址:");
						String site=input.next();
						System.out.println("订餐成功！");
						System.out.println("您订的是"+dishMeg);
						System.out.println("送餐时间"+time+"点");
						System.out.println("餐费:"+canfei+"元,送餐费"+charge+"元,总计:"+(canfei+charge)+"元");
						names[i]=name;
						dishMegs[i]=dishMeg;
						times[i]=time;
						addresses[i]=site;
						sumPrices[i]=canfei+charge;
						break;
					}
					if(!isAdd) {
						System.out.println("对不起，您的餐袋已满!");
					}
				}
				break;
			case 2:
				System.out.println("********2.查看餐袋********");
				System.out.println("序号\t订餐人\t餐品信息\t\t送餐时间\t\t送餐地址\t\t总金额\t\t订单状态");
				for (int i = 0; i < names.length; i++) {
					if(names[i]!=null) {
						String state= (states[i]==0)?"已预定":"已完成";
						String date= times[i]+"点";
						String sumPrice= sumPrices[i]+"元";
						System.out.println((i+1)+"\t"+names[i]+"\t"+dishMegs[i]+"\t"+date+"\t\t"+addresses[i]+"\t\t"+sumPrice+"\t"+state);
					}
				}
				break;
			case 3:
				System.out.println("********3.签收订单********");
				boolean isSignFind = false;
				System.out.println("请选择要签收的订单号:");
				int signOrderId = input.nextInt();
				for (int i = 0; i < names.length; i++) {
					if(names[i]!=null && states[i]==0 && signOrderId==i+1){
						states[i]=1;
						System.out.println("订单签收成功！");
						isSignFind=true;
					}
				}
				break;
			case 4:
				System.out.println("********4.删除订单********");
				boolean isDelFind = false;
				System.out.println("请输入要删除的订单号:");
				int delId = input.nextInt();
				for (int i = 0; i < names.length; i++) {
					if(names[i]!=null && states[i]==1 && delId==i+1) {
						isDelFind= true;
						for (int j = delId-1; j < names.length; j++) {
							names[j]=names[j+1];
							dishMegs[j]= dishMegs[j+1];
							times[j]= times[j+1];
							addresses[j]= addresses[j+1];
							states[j]= states[j+1];
							sumPrices[j]= sumPrices[j+1];
						}
						int enIndex= names.length-1;
						names[enIndex]= null;
						dishMegs[enIndex]=null;
						times[enIndex]=0;
						addresses[enIndex]=null;
						states[enIndex]=0;
						sumPrices[enIndex]=0;
						System.out.println("删除订单成功！");
						break;
					}else if(names[i]!=null && states[i]==0 && delId==i+1) {
						System.out.println("您选择的订单未签收，不能删除！");
						isDelFind= true;
						break;
					}
				}
				if(!isDelFind) {
					System.out.println("您要删除的订单不存在！");
				}
				break;
			case 5:
				System.out.println("********5.我要点赞********");
				System.out.println("序号"+"\t"+"菜名"+"\t"+"单价");
				for (int i = 0; i < dishNames.length; i++) {
					String price= prices[i]+"元";
					String priaiseNum= (praiseNums[i])>0 ? praiseNums[i]+"赞":"";
					System.out.println((i+1)+"\t"+dishNames[i]+"\t"+price+"\t"+priaiseNum);
				}
				System.out.println("请选择您要点赞的菜品编号:");
				int priaiseNum = input.nextInt();
				praiseNums[priaiseNum-1]++;
				System.out.println("点赞成功！");
				break;
			case 6:
				isExit=true;
				System.out.println("感谢的使用，欢迎下次光临！");
				break;
			}
			if (!isExit) {
				System.out.println("输入0返回:");
				num = input.nextInt();
			} else {
				break;
			}
		} while (num == 0);
	}
}