习题求助！

[帅帅没人爱]

代码如下：要求是输入形式是：name_quantity_price
输入时 以下划线做出区分，同时将输入的值赋给不同类型的name quantity 和price
private Product readProduct() throws IOException {

final String DELIM = "_";

String name = "";
int quantity = 0;
double price = 0.0;
/* PLACE YOUR CODE HERE */
System.out.print("Product [Name_Quantity_Price] :");
try
{
String s=new Scanner(System.in).next();
StringTokenizer st=new StringTokenizer(s,DELIM,true);

name+=st.nextToken();
quantity=Integer.parseInt(st.nextToken());
price=Double.parseDouble(st.nextToken());
}
catch(NumberFormatException e)
{
e.printStackTrace();
}
return new Product(name, quantity, price);
}

[qybao]

for example

private Product readProduct() throws Exception {

    final String DELIM = "_";

    String name = "";
    int quantity = 0;
    double price = 0.0;
    /* PLACE YOUR CODE HERE */
    System.out.print("Product [Name_Quantity_Price] :");
    try {
        String s=new Scanner(System.in).nextLine();
        if (!s.matches(".*?_\\d+_\\d+([.]\\d+)?")) { //可以做个一个判断
            thorws new Exception("the format of input data is error.");
        }
        StringTokenizer st=new StringTokenizer(s,DELIM,true);
        name+=st.nextToken();
        quantity=Integer.parseInt(st.nextToken());
        price=Double.parseDouble(st.nextToken());
    } catch(NumberFormatException e) {
        e.printStackTrace();
        thorw e; //把异常抛出，否则要自己return一个null什么的
    }
    return new Product(name, quantity, price); //要不然这里就不对了
}

[风尘中国]

使用String.split方法来做吧

import java.util.Scanner;
import java.util.StringTokenizer;
import java.io.IOException;

/**
 * Created by IntelliJ IDEA.
 * User: Administrator
 * Date: 2011-9-24
 * Time: 19:05:34
 * To change this template use File | Settings | File Templates.
 */
public class Demo1 {
    private Product readProduct() throws IOException {

        final String DELIM = "_";

        String name = "";
        int quantity = 0;
        double price = 0.0;
/* PLACE YOUR CODE HERE */
        System.out.print("Product [Name_Quantity_Price] :");
        try
        {
            String s=new Scanner(System.in).next();
            String[] inputs=s.split(DELIM);
//            StringTokenizer st=new StringTokenizer(s,DELIM,true);
//
            name+=inputs[0];
            quantity=Integer.parseInt(inputs[1]);
            price=Double.parseDouble(inputs[2]);
        }
        catch(NumberFormatException e)
        {
            e.printStackTrace();
        }
        return new Product(name, quantity, price);
    }

    public static void main(String[] args)throws Exception{
        System.out.println(new Demo1().readProduct());
    }
}

class Product{
    private String name;
    private int quantity;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getQuantity() {
        return quantity;
    }

    public void setQuantity(int quantity) {
        this.quantity = quantity;
    }

    public double getPrice() {
        return price;
    }

    public void setPrice(double price) {
        this.price = price;
    }

    private double price;

    public Product(){}

    public Product(String name,int quantity,double price){
        this.name=name;
        this.quantity=quantity;
        this.price=price;
    }

    @Override
    public String toString() {
        return "Product{" +
                "name='" + name + '\'' +
                ", quantity=" + quantity +
                ", price=" + price +
                '}';
    }
}

[帅帅没人爱]

谢谢！再问一个问题，输入的时候怎么将空格键输入进一个字符串呢？
比如说 Mp3 Player

[风尘中国]

用Scanner直接输入空格解析出来就有了
String s =new Scanner(System.in).next();
Sysetem.out.println(s);
你输入a b c d
可以输出输入的字符串
[Quote=引用 3 楼 aecsun 的回复:]
谢谢！再问一个问题，输入的时候怎么将空格键输入进一个字符串呢？
比如说 Mp3 Player
[/Quote]

[帅帅没人爱]

谢谢！我刚才提交了作业，方法参考了你给的，就是输入流换成了readLine赋值个name。总之特别感谢！

[Quote=引用 4 楼 ioe_gaoyong 的回复:]

用Scanner直接输入空格解析出来就有了
String s =new Scanner(System.in).next();
Sysetem.out.println(s);
你输入a b c d
可以输出输入的字符串
引用 3 楼 aecsun 的回复:
谢谢！再问一个问题，输入的时候怎么将空格键输入进一个字符串呢？
比如说 Mp3 Player
[/Quote]