使用useDelimiter（）连接子串 [英] Using useDelimiter() to join substrings

问题描述

我的方法 readDataFromFile（）可以读取如下文本文件：

My method readDataFromFile() can read text files like:

Bird    Golden Eagle    Eddie
Mammal  Tiger   Tommy
Mammal  Lion    Leo
Bird    Parrot  Polly
Reptile Cobra   Colin

第一列是动物的'Type'，第二列是'Species'，第三列是'Name'。

The first column is the 'Type' of animal, second column is 'Species' and third is 'Name'.

当前输出：

Bird  Golden Eagle  < (Golden and Eagle count as different substrings).
    Mammal  Tiger Tommy
    Mammal  Lion Leo
    Bird  Parrot Polly
    Reptile  Cobra Colin

• 我如何使用 useDelimiter 方法将金鹰算作一个品种？


• How would I use the useDelimiter method to make 'Golden Eagle' count as one species?

当前代码：

while(scanner.hasNextLine())
       {
       String type = scanner.next();
       String species = scanner.next();
       String name = scanner.next();
       System.out.println(type + "  " + species + " " + name);
       scanner.nextLine();

       addAnimal( new Animal(species, name, this) );
       }




推荐答案




第一行的'Golden Eagle'都用标签分隔

the first line has 'Golden Eagle' both separated by a tab

这是不对的。

您的问题来源显示了这些列全部由制表符分隔（ \t 又名 \ u0009 ），但 Golden 和 Eagle 由 space 字符分隔（ \ u0020 ）。

The source of your question shows that the columns are all separated by a tab character (\t aka \u0009), but Golden and Eagle are separated by a space character (\u0020).

请勿使用扫描程序读取文件。它非常慢，不适合解析文件。相反，使用 BufferedReader 和 readline（）方法，然后 split（）列成行。

Do not read your file using Scanner. It is very slow and not the appropriate tool for parsing your file. Instead, use a BufferedReader and the readline() method, then split() the line into columns.

演示

try (BufferedReader in = Files.newBufferedReader(Paths.get("animals.txt"))) {
    for (String line; (line = in.readLine()) != null; ) {
        String[] values = line.split("\t");
        for (String value : values)
            System.out.printf("%-15s", value);
        System.out.println();
    }
}

输出

Bird           Golden Eagle   Eddie          
Mammal         Tiger          Tommy          
Mammal         Lion           Leo            
Bird           Parrot         Polly          
Reptile        Cobra          Colin          

如你所见，金鹰文字未被分割。

As you can see, the Golden Eagle text did not get split.

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