Java-如何读取在同一行中包含Int和Strings的文本文件

Question

如果文本文件包含

1 Apple
2 Banana
3 Orange
4 Carrot
5 Lemon
6 Lime
7 Mango 

如何读取文件以将第4行胡萝卜的内容存储到变量中，将第6行Lime的内容存储到单独的变量中？

    //Get data from file
    String fruit = "";
    String greenFruit = "";


    FileReader file = new FileReader("my/file/path.txt");
    BufferedReader reader = new BufferedReader(file);

    System.out.println(fruit);
    System.out.println(greenFruit);

最终结果是类似的东西>

"Fruit number 5 is a Lemon and Fruit Number 6 is a Lime"

如果文本文件包含1个Apple 2香蕉3橙4胡萝卜5柠檬6酸橙7芒果，如何读取该文件以存储内容，例如，将第4行胡萝卜变成变量，而将第6行石灰变成...。 >

Answer 1

尝试这样的事情：

String line = "";
String[] tokens;
int number;
String name;

while((line = reader.readLine()) != null)
{
    tokens = line.split(" ");

    // Use the following if you would rather split on whitespace for tab separated data
    // tokens = line.split("\\s+");

    number = Integer.parseInt(tokens[0]);
    name = tokens[1];

    System.out.println("Fruit number " + number + " is a " + name + "."
}

Answer 2

我们可以使用Java NIO api来读取文件中的所有行，

Answer 3

Fruit number 1 is a Apple and Fruit number 2 is a Banana and Fruit number 3 is a Orange and Fruit number 4 is a Carrot and Fruit number 5 is a Lemon and Fruit number 6 is a Lime and Fruit number 7 is a Mango

Answer 4

Java 8样式：

Answer 5

您可以使用

// normal solution
try (Stream<String> stream = Files.lines(Paths.get(fileName))) {
        stream.foreach(line -> {
           tokens = line.split(" ");

           number = Integer.parseInt(tokens[0]);
           name = tokens[1];
           System.out.println("Fruit number " + number + " is a " + name + "."
        });

        } catch (IOException e) {
            e.printStackTrace();
        }


// more OOP style
public class Fruit {
  private int number;
  private String name;

  public Fruit(String line) {
     String[] line = line.split(" ");
     this.number = Integer.parseInt(line[0]);
     this.name = line[1];
  }  
}
List<Fruit> list = new ArrayList;
try (Stream<String> stream = Files.lines(Paths.get(fileName))) {
            //1. convert all content to a object
            //2. convert it into a List
            list = stream
                    .map(Fruit::new)
                    .collect(Collectors.toList());

        } catch (IOException e) {
            e.printStackTrace();
        }

// then you can loop the list get what you want

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