Question

while (inFile.hasNextLine()) {
    SortedArrayList<Fruit> fruitList = new SortedArrayList<Fruit>();
    String marketName = inFile.next();
    while (inFile.hasNexLine()) {
        String line = inFile.nextLine();
        if(line.isEmpty())
            break;
        else {
                Sting fruitName = inFile.next();
                int price = inFile.nextInt();
                int stock = inFile.nextInt();
                fruit = new Fruit(fruitName, price, stock);
                fruitList.insert(fruit);
        }        
    }
    market = new Market(marketName, fruitList);
    marketList.insert(market);
}

我想要阅读文本文件文本文件的内容如下：

A_market  
apple 1000 11  
orange 2000 6   
grape 1600 17

B_market  
apple 900 20   
orange 2100 12  

...

每个市场都无法提前知道每种水果的数量每个市场将用空行分隔如何识别文本文件中的空白行？

我希望在嵌套迭代器的基础上留空我尝试isEmpty（），正则表达式，检查字母表等。
但是，错误不是意志。

再次抱歉问题。
如何提供帮助将不胜感激。

Answer 1

一个问题可能与混合nextLine和next / nextInt有关。请参阅Skipping nextLine() after use next(), nextInt() or other nextFoo() methods。

通常混合这些是一个坏主意。选择其中一个。

您的部分内容也会被彻底删除：

// this line is being skipped
// when it's not empty
String line = inFile.nextLine();
if(line.isEmpty())
    break;
else {
    Sting fruitName = inFile.next();
    int price = inFile.nextInt();
    int stock = inFile.nextInt();
    ...
}

我建议每次想要从一行获取每个水果的信息时使用第二个Scanner：

while (inFile.hasNextLine()) {
    String marketName = inFile.nextLine();

    while (inFile.hasNextLine()) {
        String line = inFile.nextLine();
        if (line.isEmpty()) {
            break;
        }

        // create a new Scanner just
        // for this line so it doesn't
        // mess up the calls to nextLine
        Scanner lineIn = new Scanner(line);

        Sting fruitName = lineIn.next();
        int price = lineIn.nextInt();
        int stock = lineIn.nextInt();
        ...
    }

    ...
}

Answer 2

Java代码

 while (inFile.hasNextLine()) {
        String marketName = inFile.next();
        while (inFile.hasNexLine()) {
            String line = inFile.nextLine();
            if(line.length()==0)     //blank line
                break;
            else {
                    Sting fruitName = inFile.next();
                    int price = inFile.nextInt();
                    int stock = inFile.nextInt();
                    fruit = new Fruit(fruitName, stock, price);
                    fruitList.insert(fruit);
            }        
        }
        market = new Market(marketName, fruitList);
        marketList.insert(market);
    }

我如何嵌套Iterator？

2 个答案: