我需要一个文件读取器来逐行读取文本文件并将其格式化为Java

Question

我有一个文本文件，格式如下：

Han Solo:1000
Harry:100
Ron:10
Yoda:0

我需要创建一个arrayList对象，该对象存储玩家的姓名（ Han Solo ）及其得分（ 1000 ）作为属性。 我希望能够通过逐行读取文件并拆分字符串以获取所需的属性来制作此arrayList。 我尝试使用Scanner对象，但没有成功。 在此方面的任何帮助将不胜感激，谢谢。

Answer 1

您可以创建一个Class Call player 。 playerName和score将是属性。

public class Player {
  private String playerName;
  private String score;
  // getters and setters
}

然后您可以创建一个List

List<Player> playerList=new ArrayList<>();

现在，您可以尝试完成任务。

此外，您可以从文件中读取内容，并用: split每一行，并将第一部分作为playerName ，第二部分作为score 。

   List<Player> list=new ArrayList<>();
   while (scanner.hasNextLine()){
       String line=scanner.nextLine();
       Player player=new Player();
       player.setPlayerName(line.split(":")[0]);
       player.setScore(line.split(":")[1]);
       list.add(player);
   }     

Answer 2

您可以拥有一个像这样的Player类：

class Player { // Class which holds the player data
    private String name;
    private int score;

    public Player(String name, int score) {
        this.name = name;
        this.score = score;
    }

    // Getters & Setters
    // Overrride toString()  - I did this. Its optional though.
}

您可以解析包含如下数据的文件：

List<Player> players = new ArrayList<Player>();
try {
    BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream("input.txt"))); // I used BufferedReader instead of a Scanner
    String line = null;
    while ((line = br.readLine()) != null) {
        String[] values = line.split(":"); // Split on ":"
        players.add(new Player(values[0], Integer.parseInt(values[1]))); // Create a new Player object with the values extract and add it to the list
    }
} catch (IOException ioe) {
    // Exception Handling
}
System.out.println(players); // Just printing the list. toString() method of Player class is called.

Answer 3

如果您有对象：

public class User
{
    private String name;
    private int score;

    public String getName()
    {
        return name;
    }

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

    public int getScore()
    {
        return score;
    }

    public void setScore(int score)
    {
        this.score = score;
    }

}

创建一个从文件读取的Reader类：

public class Reader
{
    public static void main(String[] args)
    {
        List<User> list = new ArrayList<User>();
        File file = new File("test.txt");
        BufferedReader reader = null;
        try
        {
            reader = new BufferedReader(new FileReader(file));
            String line;
            while ((line = reader.readLine()) != null)
            {
                String[] splitedString = line.split(":");
                User user = new User();
                user.setName(splitedString[0]);
                user.setScore(Integer.parseInt(splitedString[1]));
                list.add(user);
            }
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
        finally
        {
            if (reader != null)
            {
                try
                {
                    reader.close();
                }
                catch (IOException e)
                {
                    e.printStackTrace();
                }
            }
        }

        for (User user : list)
        {
            System.out.println(user.getName()+" "+user.getScore());
        }
    }
}

输出将是：

Han Solo 1000哈里100罗恩10尤达0

Answer 4

假设您有一个名为Player的类，该类包含两个数据成员-String类型的名称和int类型的score 。

List<Player> players=new ArrayList<Player>();
        BufferedReader br=null;
        try{
            br=new BufferedReader(new FileReader("filename"));
            String record;
            String arr[];
            while((record=br.readLine())!=null){
                arr=record.split(":");
                //Player instantiated through two-argument constructor
                players.add(new Player(arr[0], Integer.parseInt(arr[1])));
            }
        } catch (FileNotFoundException e) {             
            e.printStackTrace();
        } catch (IOException e) {               
            e.printStackTrace();
        }
        finally{
            if(br!=null)
                try {
                    br.close();
                } catch (IOException e1) {                      
                    e1.printStackTrace();
                }
        }

Answer 5

对于小文件（小于8kb），您可以使用此文件

import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.List;

public class NameScoreReader {

List<Player> readFile(final String fileName) throws IOException
{
    final List<Player> retval = new ArrayList<Player>();

    final Path path = Paths.get(fileName);
    final List<String> source = Files.readAllLines(path, StandardCharsets.UTF_8);
    for (final String line : source) {
        final String[] array = line.split(":");
        if (array.length == 2) {
            retval.add(new Player(array[0], Integer.parseInt(array[1])));
        } else {
            System.out.println("Invalid format: " + array);
        }
    }
    return retval;
}


class Player {

    protected Player(final String pName, final int pScore) {
        super();
        this.name = pName;
        this.score = pScore;
    }

    private String name;

    private int score;

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

    public int getScore()
    {
        return this.score;
    }
    public void setScore(final int score)
    {
        this.score = score;
    }

}

}

Answer 6

读取文件并将其转换为可用于结果的字符串和拆分函数。

public static String getStringFromFile(String fileName) {
        BufferedReader reader;
        String str = "";
        try {
            reader = new BufferedReader(new FileReader(fileName));
            String line = null;
            StringBuilder stringBuilder = new StringBuilder();
            while ((line = reader.readLine()) != null) {
                stringBuilder.append(line);
                stringBuilder.append("\n");
            }
                str = stringBuilder.toString();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }

    public static void main(String[] args) {
        String stringFromText = getStringFromFile("C:/DBMT/data.txt");
        //Split and other logic goes here
    }