小白在實訓的學習實訓的第二週開始寫圖書管理系統程式碼，接下來是記錄學習的過程。
建立了一個Library 類和Booktest類
建立Library類對圖書管理系統 建立方法，然後在寫構造方法

package com.lenovo.www.entity;

public class Library {

    private int Id;
    private String BookName;
    private String Author;
    private String Reader;
    private String price;
    private
 
 String TypeId;
    private String BookDesc;
    public Library() {}


    public Library(int id, String bookName, String author, String reader, String price, String typeId,
            String bookDesc) {
        super();
        Id = id;
        BookName = bookName;
        Author = author;
        Reader = reader;
        this
 
.price = price;
        TypeId = typeId;
        BookDesc = bookDesc;
    }


    public int getId() {
        return Id;
    }
    public void setId(int id) {
        Id = id;
    }
    public String getBookName() {
        return BookName;
    }
    public void setBookName(String bookName) {
        BookName = bookName;
    }
    public
 
 String getAuthor() {
        return Author;
    }
    public void setAuthor(String author) {
        Author = author;
    }
    public String getReader() {
        return Reader;
    }
    public void setReader(String reader) {
        Reader = reader;
    }
    public String getPrice() {
        return price;
    }
    public void setPrice(String price) {
        this.price = price;
    }
    public String getTypeId() {
        return TypeId;
    }
    public void setTypeId(String typeId) {
        TypeId = typeId;
    }
    public String getBookDesc() {
        return BookDesc;
    }
    public void setBookDesc(String bookDesc) {
        BookDesc = bookDesc;
    }

}

用ArrayList進行儲存資訊，if  ....else語句迴圈執行，建立掃描器，使使用者可以輸入

package com.lenovo.www.entity;
/**
* private int id;
private String bookName;// 圖書名稱
private String author;// 作者
private String reader;// 借閱人
private String price;// 圖書價格
private String TypeId;// 圖書類別
private String bookDesc;// 備註
*/

import java.awt.print.Book;
import java.util.ArrayList;
import java.util.Scanner;

public class Booktest {
static ArrayList bookList = new ArrayList<>();

public Booktest(int i, String string, String string2, String string3, String string4, String string5,
        String string6) {
    // TODO Auto-generated constructor stub
}

public static void main(String[] args) {
    System.out.println("請輸入選單序號，");
    System.out.println("查詢圖書，1");
    System.out.println("新增圖書，2");
    System.out.println("刪除圖書，3");
    System.out.println("退出程式，0");
    Scanner src = new Scanner(System.in);
    if (src.nextInt() == 1) {
        Library s1 = new Library(321, "《白鹿原》", "陳忠實", "小明", "30.00元", "文學類", "  借閱人數較多 ");
        Library s2 = new Library(322, "《西遊記》", "吳承恩", "小紅", "35.00元", "文學類", "   ");
        Library s3 = new Library(323, "《紅樓夢》", "曹雪芹", "小白", "36.00元", "文學類", "   ");
        Library s4 = new Library(324, "《水滸傳》", "施耐庵", "小黑", "37.00元", "文學類", "  未到指定日期歸還 ");
        Library s5 = new Library(325, "《三國演義》", "羅貫中", "小明", "40.00元", "文學類", "   ");
        Library s6 = new Library(326, "《白夜行》", "東野奎吾", "小藍", "35.00元", "懸疑類", "   ");

        bookList.add(s1);
        bookList.add(s2);
        bookList.add(s3);
        bookList.add(s4);
        bookList.add(s5);
        bookList.add(s6);
        for (int i = 0; i < bookList.size(); i++) {

            Library a = bookList.get(i);

            System.out.println("圖書編號 : " + a.getId() + "  圖書名稱： " + a.getBookName() + "  作者： " + a.getAuthor()
                    + "     借閱人姓名： " + a.getReader() + " 圖書價格： " + a.getPrice() + " 圖書類別 ：" + a.getTypeId()
                    + " 備註：  " + a.getBookDesc());
        }
    } else  {



        System.exit(0);
    }

}

}

   這是第一天的程式碼，日後不斷完善
   寫這段程式碼中出現了錯誤

Library s1 = new Library(321, “《白鹿原》”, “陳忠實”, “小明”, “30.00元”, “文學類”, ” 借**閱人數較多 “);
Library s2 = new Library(322, “《西遊記》”, “吳承恩”, “小紅”, “35.00元”, “文學類”, ” “);
Library s3 = new Library(323, “《紅樓夢》”, “曹雪芹”, “小白”, “36.00元”, “文學類”, ” “);
Library s4 = new Library(324, “《水滸傳》”, “施耐庵”, “小黑”, “37.00元”, “文學類”, ” 未到指定日期歸還 “);
Library s5 = new Library(325, “《三國演義》”, “羅貫中”, “小明”, “40.00元”, “文學類”, ” “);
Library s6 = new Library(326, “《白夜行》”, “東野奎吾”, “小藍”, “35.00元”, “懸疑類”, ” “);

****由於粗心將Library類寫成了booklist**

定義的int整形類卻輸入了0501這種不符合int型別的數

private int id;

Library s2 = new Library(322, "《西遊記》", "吳承恩", "小紅", "35.00元", "文學類", "   ");
    Library s2 = new Library(0501, "《西遊記》", "吳承恩", "小紅", "35.00元", "文學類", "   ");（錯誤的） 

“`