java模拟实现图书检索系统 (基础版)，供大家参考，具体内容如下
练习实现3个简单的功能，没有优化，可以根据需求，自行添加想要实现的功能。
Book.java
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package com.demo3;
public class Book {
private int id; private String name; private double price;
public Book(){}
public Book( int id, String name, double price) { this .id = id; this .name = name; this .price = price; }
public int getId() { return id; }
public void setId( int id) { this .id = id; }
public String getName() { return name; }
public void setName(String name) { this .name = name; }
public double getPrice() { return price; }
public void setPrice( double price) { this .price = price; }
public void showMess() { System.out.println( "Book{" + "编号=" + getId() + ", 书名='" + getName() + ", 价格=" + getPrice() + '}' ); } } |
Tool.java
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package com.demo3;
import com.sun.scenario.effect.impl.sw.sse.SSEBlend_SRC_OUTPeer;
import java.math.BigDecimal; import java.util.Arrays;
public class Tools {
private Book[] books = new Book[ 20 ];
private int size;
public void init(){ Book book1 = new Book( 1 , "老人与海" , 29.8 ); Book book2 = new Book( 2 , "狂人日记" , 36.7 ); Book book3 = new Book( 3 , "玫瑰的葬礼" , 19.2 ); Book book4 = new Book( 4 , "宇宙源头" , 19.2 );
books[ 0 ]=book1; books[ 1 ]=book2; books[ 2 ]=book3; books[ 3 ]=book4; size= 4 ; }
public Book[] getBooks() { return books; }
public void setSize( int size) { this .size = size; }
/*根据编号查询图书*/ public void fingBookById(Book[] books, int id){
int i= 0 ; while (i<size){ if (books[i].getId()== id){ System.out.println( "检索信息: " ); System.out.println( "-------------------Content----------------------" ); books[i].showMess(); System.out.println( "------------------------------------------------" ); break ; } i++; } if (i>=size){ System.out.println( "暂无信息" ); } }
/*根据价格查找图书，返回一个新的数组*/ public Book[] findBookeByPrice(Book[] books, double price){
Book[] newBooks= new Book[books.length]; int length= 0 ;
int i= 0 ; int j= 0 ; /*注意，这里添加一个j*/ while (i<size){ /*提高精度,这里用到了BigDecimal类*/ BigDecimal x1 = new BigDecimal(books[i].getPrice()); BigDecimal x2 = new BigDecimal(price); if (x1.floatValue()==x2.floatValue()){ /*这里用到j，而不是下标i，如果是下标i的话，则就会出现nullpointerexception异常，因为if程序体中的 i的取值不是连续的*/ newBooks[j++]= books[i]; length++; } i++; }
/*这里用到了Array集合类中的copyRange静态方法*/ newBooks= Arrays.copyOfRange(newBooks, 0 ,length); return newBooks; } } |
BookTest.java
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package com.demo3;
import java.util.Scanner;
public class BookTest {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in); /*创建工具类，对其进行初始化*/ Tools tool = new Tools(); tool.init();
prof: while ( true ) { System.out.println( "========图书检索系统=======" ); System.out.println( "1，【编号检索】 2，【价格检索】 3，【退出】" ); System.out.print( "【输入检索【类型】: " );
int num = scanner.nextInt();
while ( true ) {
switch (num) { case 1 : System.out.println( "进入图书【编号】检索:" ); System.out.print( "输入检索【编号】: " ); int checkId = scanner.nextInt(); tool.fingBookById(tool.getBooks(), checkId); break ;
case 2 : System.out.println( "进入图书【价格】检索" ); System.out.print( "输入检索【价格】：" ); double price = scanner.nextDouble(); Book[] books = tool.findBookeByPrice(tool.getBooks(),price); if (books.length> 0 ){ System.out.println( "-------------------Content----------------------" ); for (Book book :books){ book.showMess(); } System.out.println( "------------------------------------------------" ); }; break ; case 3 : System.out.println( "退出成功" ); break prof; }; break ; } } } } |
程序执行如下：
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。
原文链接：https://blog.csdn.net/qq_45399396/article/details/119239512