java新手代码大全_java新手的一串代码「建议收藏」

importjava.util.*;importjava.io.*;abstractclassGood{Stringname;doubleprice;Good(Stringname,doubleprice){this.name=name;this.price=price;}}classBookextendsGood{Stringname;…

import java.util.*;

import java.io.*;

abstract class Good{

String name;

double price;

Good(String name,double price){

this.name=name;

this.price=price;

}

}

class Book extends Good{

String name;

double price;

int passage;

Book(String name,double price,int passage){

super(name,price);

this.passage=passage;

}

public String toString(){

return “name:”+name+” price:”+price+” passage:”+passage;

}

}

class NoGoodException extends Exception{

public NoGoodException(String msg){

super(msg);

}

}

interface Shopper{

void add(Good good);

void buy(String n) throws NoGoodException;

}

class Shop implements Shopper {

private List bookArrayList = new ArrayList<>();

@Override

public void add(Good good) {

if (good instanceof Book) {

addBook((Book) good);

}}

private void addBook(Book book) {

bookArrayList.add(book);

}

public void buy(String n) throws NoGoodException {

for (Book book : bookArrayList) {

if (book.name == n) {

System.out.println(“You buy it!!! ” + book.toString());

bookArrayList.remove(book);

return;

}

}

throw new NoGoodException(n + ” no found”);}

}

public class a {

public static void main(String[] args) throws Exception {

Good book1 = new Book(“book1”, 10, 155);

Good book2 = new Book(“book2”, 12, 168);

Shop shop = new Shop();

shop.add(book1);

shop.add(book2);

try {

shop.buy(“book1”);

shop.buy(“book20”);

} catch (NoGoodException a) {

System.out.println(a.getMessage());

}

}

}

只能输出一行。。。而且输出的结果明显不是我想要的

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