如何使用Scanner的分隔符方法

Question

我目前正致力于游戏风险的实施。在构建国家，大陆及其邻接的Board类中，我正在阅读三个不同的文本文件。当我建造一个新的大陆时，它的“大陆”构造函数需要以下内容 （String name，int bonusArmies，ArrayList memberCountries）。 现在，我正在使用扫描仪从一个组织如下的文本文件中读取， 它拥有的名称，奖金军队以及每条线上的其余部分都是其成员国。

北美，5，阿拉斯加，艾伯塔省，中美洲，美国东部，格陵兰岛，西北地区，安大略省，魁北克省，美国西部 南美洲，2，阿根廷，巴西，委内瑞拉 欧洲，5，英国，冰岛，北欧，斯堪的那维亚，南欧，乌克兰，西欧 非洲，3，刚果，东非，埃及，马达加斯加，北非，南非 亚洲，7，阿富汗，中国，印度，伊尔库茨克，日本，堪察加半岛，中东，蒙古，暹罗，西伯利亚，乌拉尔，雅库茨克 澳大利亚，2，澳大利亚东部，印度尼西亚，LotR，新几内亚，西澳大利亚

我知道我需要为Scanner设置一个分隔符，我已尝试过多种方法，但无济于事。这是我尝试创建Continents散列图的示例。

public void createContinents()
{   

    Scanner inputTwo = new Scanner( new File( "continents.txt");

while( inputTwo.hasNext())  //continues to create and add countries until their are none next
{   
    String line = inputTwo.nextLine();  //stores the entire line
    Scanner lineScan = new Scanner( line);  //passes the entire line into Scanner
    lineScan.useDelimiter(","); //sets the Scanner's delimiter pattern

    String name = inputTwo.next();  //stores the first String which is the name of the current continent being created
    System.out.println( " the name is" + name);

    int bonusArmies = inputTwo.nextInt();   //stores the second String which is casted into an int for the continent bonus armies
    System.out.println(" the number of bonus armies is" + bonusArmies);

    ArrayList<Country> memberCountries = new ArrayList<Country>();  //creates an arraylist to hold the member countries of current continent

    while( inputTwo.hasNext())  //goes through the rest of the line to add the member countries until it reaches the end of the line
    {   

        memberCountries.add( countries.get(inputTwo.next()));//gets string name of country and pass it as key to store into temp arraylist of countries         
        System.out.println( "the member countries" + memberCountries);
    }

        continent = new Continent( name,  bonusArmies,  memberCountries);   //creates continent
        continents.put(name , continent);   //associates a key to the current continent

}


    inputTwo.close();

 }    

这是该图片中的文字。

    PS C:\Users\repti_000\desktop\risk\homeworks2120\game> java BoardTester
     the name is
    SouthAmerica,2,Argentina,Brazil,Venezuela 

    Exception in thread "main" java.util.InputMismatchException
    at java.util.Scanner.throwFor(Unknown Source)
    at java.util.Scanner.next(Unknown Source)
    at java.util.Scanner.nextInt(Unknown Source)
    at java.util.Scanner.nextInt(Unknown Source)
    at Board.createContinents(Board.java:66)
    at Board.loadBoard(Board.java:141)
    at Board.<init>(Board.java:27)
    at BoardTester.main(BoardTester.java:7)
   PS C:\Users\repti_000\desktop\risk\homeworks2120\game>

Answer 1

您从inputTwo而不是lineScan获取数据。你应该在这里考虑更清晰的名字，这样可以更容易地发现这类问题。而不是inputTwo mapData或worldScanner而不是lineScan可能是continentData。

Answer 2

我将扫描仪和一些变量重命名为更清晰，并添加了一些带有CHANGED的注释。我想知道为什么你的hashmap大陆看起来像大陆（名称，大陆），而你的商店是大陆的名称（当你用构造函数给它时）。使用continent.getName（）似乎是一种更好的做法。

正如RotN爵士指出的那样，你使用了错误的扫描仪，你的名字确实不清楚。尽量让你的变量名更清晰一些，这应该有时间。

    public void createContinents()  { 

    //  Scan the continents.txt file
    Scanner worldScan = new Scanner( new File( "continents.txt");

    //  While worldScan has a next line, run loop
    //  CHANGED: not hasNext(), but hasNextLine()
    while( worldScan.hasNextLine()) {

        //  Create a scanner for the selected line in worldScan
        String continentLine = inputTwo.nextLine();
        Scanner continentScan = new Scanner(continentLine);
        continentScan.useDelimiter(",");

        //  Grab the continent from the scanner
        String name = continentScan.next();
        System.out.println( " the continent name is" + name);

        //  Grab the armies from the scanner
        //  CHANGED: you read it out as a string, not as an int
        int bonusArmies = Integer.toString(continentScan.next());
        System.out.println(" the number of bonus armies is" + bonusArmies);

        //  Instantiate loop variable countries
        ArrayList<Country> memberCountries = new ArrayList<Country>();

        while( continentScan.hasNext()) {
            memberCountries.add(countries.get(continentScan.next()));
            System.out.println( "the member countries" + memberCountries);
        }

        //  Instantiate loop variable continent
        Continent continent = new Continent( name,  bonusArmies,  memberCountries);

        //  Add continent to the hashmap
        continents.put(name,continent);

        continentScan.close();
    }

    worldScan.close();
 }