作者:AlexTan
E-mail: [email protected]
上一篇博客我們提到代碼太臃腫,那麼這篇博客將來解決這個問題。這篇博客將把上篇博客的代碼改成MVC編程模式,MVC即models,views,controller,詳細介紹請繼續往下看。
MVC編程模式介紹:
-
Model(模型)表示應用程序核心(比如數據庫記錄列表)。
-
View(視圖)顯示數據(數據庫記錄)。
-
Controller(控制器)處理輸入(寫入數據庫記錄)。
那麼根據MVC編程模式,我們把上次的代碼分成一下幾個模塊:
注:ui即view。
我們把增刪改查的函數放入control裏,把輸出輸入放在MainClass裏,把Book,以及BookList放在model下,這樣程序看起來就更系統化了,下面是具體代碼:
Operator.java:
package control;
import model.Book;
import model.BookList;
public class Operator {
public boolean addBook(String bookname, String author, float price)
{
Book book = new Book(bookname,author,price);
if (BookList.booklist.add(book))
{
return true;
}
else
return false;
}
public boolean deleteBook(int id)
{
if(BookList.booklist.remove(id) != null)
{
return true;
}
else
return false;
}
public boolean changeBoo(int id,String bookname, String author, float price)
{
Book book = (Book) BookList.booklist.get(id);
if(book.setBook(bookname,author,price))
return true;
else
return false;
}
public void findBoo(int id)
{
Book book = (Book)BookList.booklist.get(id);
System.out.println("查找成功,您查找到的書爲第"+(id+1)+"本書!"+"書名爲:"+book.getBookname()+" 作者:"+book.getAuthor()+" 單價:"+book.getPrice()+"元/本");
}
public int orderFind(int number)
{
//System.out.println(number);
if(number <= BookList.booklist.size())
{
int id = number - 1;
return id;
}
else
return -1;
}
public int nameFind(String name)
{
int id = -1;
for(int i = 0; i < BookList.booklist.size(); i++)
{
Book book = (Book)BookList.booklist.get(i);
if(book.getBookname().equals(name))
{
id = i;
break;
}
else if(i<BookList.booklist.size())
continue;
else
{
System.out.println("未查找到您想要的書名");
break;
}
}
return id;
}
public void printAllBook()
{
for (int i = 0; i < BookList.booklist.size(); i++)
{
Book book = (Book)BookList.booklist.get(i);
System.out.println("第"+(i+1)+"本書名:"+book.getBookname()+" 作者:"+book.getAuthor()+" 單價:"+book.getPrice()+"元/本");
}
}
}
Book.java和以前的一樣,沒發生任何變化。
BookList.java:
註釋部分是把load加進構造函數裏,但是這樣運行沒成功,所以還是用的tool:
package model;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
/*
public class BookList extends ArrayList{
public static BookList booklist = new BookList();
public BookList()
{
try {
String filename = "D:\\Users\\alext\\workspace\\first\\book.txt";
File file = new File(filename);
BufferedReader reader = new BufferedReader(new FileReader(file));
String temp;
while((temp = reader.readLine()) != null)
{
String bookname = temp.split(",")[0];
String author = temp.split(",")[1];
String pricestr = temp.split(",")[2];
float price = Float.parseFloat(pricestr);
Book book = new Book(bookname,author,price);
this.booklist.add(book);
}
reader.close();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (NumberFormatException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
*/
public class BookList{
public static ArrayList booklist = new ArrayList();
}
IO.java:
這個文件有一點小的變化,主要是用的booklist不一樣了:
package tool;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;
import model.Book;
import model.BookList;
import ui.MainClass;
public class IO {
public void load()
{
try {
String filename = "D:\\Users\\alext\\workspace\\first\\book.txt";
File file = new File(filename);
BufferedReader reader = new BufferedReader(new FileReader(file));
String temp;
while((temp = reader.readLine()) != null)
{
String bookname = temp.split(",")[0];
String author = temp.split(",")[1];
String pricestr = temp.split(",")[2];
float price = Float.parseFloat(pricestr);
Book book = new Book(bookname,author,price);
BookList.booklist.add(book);
}
reader.close();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (NumberFormatException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void save()
{
String fileName = "D:\\Users\\alext\\workspace\\first\\book.txt";
String allbook="";
for(int i = 0; i < BookList.booklist.size(); i++)
{
Book book = (Book)BookList.booklist.get(i);
String temp = book.getBookname() + "," + book.getAuthor() + "," + book.getPrice() + "\r\n";
allbook += temp;
}
try {
File file1 = new File(fileName);
FileWriter fileWriter;
fileWriter = new FileWriter(file1);
fileWriter.write(allbook);
fileWriter.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
MainClass.java:
package ui;
import java.util.ArrayList;
import java.util.Scanner;
import control.Operator;
import model.Book;
import model.BookList;
import tool.IO;
public class MainClass {
/*
public static final int SIZE = 10;
Book[] booklist = new Book[SIZE];
*/
public MainClass()
{
Scanner scan = new Scanner(System.in);
IO io = new IO();
io.load();
printMenu();
while(true)
{
//讀取用戶輸入
int choice = scan.nextInt();
if(choice == 5)
{
io.save();
System.out.println("成功退出系統,歡迎再次光臨!");
break;
}
switch(choice)
{
case 1: addBook(); break;
case 2: deleteBoo(); break;
case 3: changeBoo(); break;
case 4: findBoo(); break;
default: System.out.println("輸入非法"); printMenu(); continue;
}
}
/*
while(true)
{
//根據用戶輸入調用不同方法
if(choice == 1)
{
addBook();
}
else if(choice == 2)
{
deleteBoo();
}
else if(choice == 3)
{
changeBoo();
}
else if(choice == 4)
{
findBoo();
}
else if(choice == 5)
{
System.out.println("成功退出系統,歡迎再次光臨!");
break;
}
}
*/
}
void printMenu()
{
//打印菜單
System.out.println("歡迎...");
System.out.println("增加圖書...1");
System.out.println("刪除圖書...2");
System.out.println("修改圖書...3");
System.out.println("查詢圖書...4");
System.out.println("退出系統...5");
}
void addBook()
{
System.out.println("當前共有:"+BookList.booklist.size()+"本書!");
Scanner scan = new Scanner(System.in);
System.out.println("請輸入圖書名:");
String bookname = scan.next();
System.out.println("請輸入作者:");
String author = scan.next();
System.out.println("請輸入單價:");
float price = scan.nextFloat();
Operator operator = new Operator();
boolean isSuccess = operator.addBook(bookname, author, price);
if(isSuccess)
{
System.out.println("增加成功!");
}
else
{
System.out.println("增加失敗!");
}
operator.printAllBook();
}
void deleteBoo()
{
Scanner scan = new Scanner(System.in);
while(true)
{
System.out.println("請輸入按哪種方法刪除圖書:1、序號/2、書名/3、返回主菜單");
int choose = scan.nextInt();
if(choose == 1)
{
System.out.println("請輸入要刪除第幾本書:");
int id = scan.nextInt();
Operator operator = new Operator();
id = operator.orderFind(id);
//System.out.println(id);
if(id > -1)
{
/*
for(int i = id; i < count - 1 ; i++)
booklist[i]=booklist[i+1];
*/
boolean isSuccess = operator.deleteBook(id);
if(isSuccess)
System.out.println("刪除成功!");
else
System.out.println("刪除失敗!");
operator.printAllBook();
}
else
{
System.out.println("輸入錯誤!");
}
}
else if(choose == 2)
{
System.out.println("請輸入您要刪除的書名:");
String name = scan.next();
Operator operator = new Operator();
int id = operator.nameFind(name);
if(id > -1)
{
/*
for(int j = id; j<count-1; j++)
{
booklist[j]=booklist[j+1];
}
*/
boolean isSuccess = operator.deleteBook(id);
if(isSuccess)
System.out.println("刪除成功!");
else
System.out.println("刪除失敗!");
operator.printAllBook();
}
else
{
System.out.println("未查找到您想要的書名");
}
}
else if(choose == 3)
{
printMenu();
break;
}
else
{
System.out.println("輸入非法!");
}
}
}
void changeBoo()
{
Scanner scan = new Scanner(System.in);
while(true)
{
System.out.println("請輸入按哪種方法修改圖書:1、序號/2、書名/3、返回主菜單");
int choose = scan.nextInt();
if(choose == 1)
{
System.out.println("請輸入要修改第幾本書:");
int number = scan.nextInt();
Operator operator = new Operator();
int id = operator.orderFind(number);
if(id > -1)
{
Book book = (Book)BookList.booklist.get(id);
//System.out.println("原書名爲:"+booklist[id].getBookname()+" 請輸入你要修改爲什麼書名:");
System.out.println("原書名爲:"+book.getBookname()+" 請輸入你要修改爲什麼書名:");
String str = scan.next();
System.out.println("請輸入作者:");
String author = scan.next();
System.out.println("請輸入單價:");
float price = scan.nextFloat();
//booklist[id].setBook(str,author,price);
boolean isSuccess = operator.changeBoo(id,str,author,price);
if(isSuccess)
System.out.println("修改成功!");
else
System.out.println("修改失敗!");
operator.printAllBook();
}
else
{
System.out.println("輸入錯誤!");
}
}
else if(choose == 2)
{
System.out.println("請輸入您要修改的書名:");
String name = scan.next();
Operator operator = new Operator();
int id = operator.nameFind(name);
if(id > -1)
{
Book book = (Book)BookList.booklist.get(id);
//System.out.println("原書名爲:"+booklist[id].getBookname()+" 請輸入你要修改爲什麼書名:");
System.out.println("原書名爲:"+book.getBookname()+" 請輸入你要修改爲什麼書名:");
String str = scan.next();
System.out.println("請輸入作者:");
String author = scan.next();
System.out.println("請輸入單價:");
float price = scan.nextFloat();
//booklist[id].setBook(str,author,price);
boolean isSuccess = operator.changeBoo(id,str,author,price);
if(isSuccess)
System.out.println("修改成功!");
else
System.out.println("修改失敗!");
operator.printAllBook();
}
}
else if(choose == 3)
{
printMenu();
break;
}
else
{
System.out.println("輸入非法!");
}
}
}
void findBoo()
{
Scanner scan = new Scanner(System.in);
Operator operator = new Operator();
while(true)
{
System.out.println("請輸入按哪種方法查找圖書:1、序號/2、書名/3、返回主菜單");
int choose = scan.nextInt();
if(choose == 1)
{
System.out.println("請輸入要查找第幾本書:");
int number = scan.nextInt();
int id = operator.orderFind(number);
if(id > -1)
{
operator.findBoo(id);
}
else
{
System.out.println("輸入錯誤!");
}
}
else if(choose == 2)
{
System.out.println("請輸入您要查找的書名:");
String name = scan.next();
int id = operator.nameFind(name);
if(id > -1)
{
operator.findBoo(id);
}
}
else if(choose == 3)
{
printMenu();
break;
}
else
{
System.out.println("輸入非法!");
}
}
}
public static void main(String[] args) {
// TODO Auto-generated method stub
new MainClass();
}
}
好了!這樣就把以前的代碼改成MVC編程模式了,沒什麼基礎的人可能現在不知道這樣有什麼作用,等在接下來的文章裏,你便會發現它的神奇之處!
請期待下一篇:Java入門教程之圖書管理系統(由簡入繁)(五)
轉載請註明出處:http://blog.csdn.net/alextan_/article/details/65450781