Question

我有一个文本文件，格式如下：

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

我需要创建一个对象的arrayList，它将玩家的名字（Han Solo）和他们的分数（1000）存储为属性。我希望能够通过逐行读取文件并拆分字符串以获得所需的属性来创建此arrayList。我尝试使用Scanner对象，但没有走远。对此有任何帮助将非常感谢，谢谢。

Answer 1

您可以创建班级电话player。 playerName和score将成为属性。

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

然后您可以创建List

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

现在你可以尝试完成你的任务了。

此外，您可以在split之前阅读文件和:每行，并将第一部分设为playerName，将第二部分设为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

你可以拥有这样的Player课程： -

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.
}

您可以解析包含以下数据的文件： -

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

如果你有对象：

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;
    }

}

创建一个从文件中读取的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 哈利100 罗恩10 尤达0

Answer 4

假设您有一个名为播放器的类，它包含两个数据成员 - String类型的 name 和int类型的得分。

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

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以申请结果的字符串和拆分功能。

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
    }

我需要让文件阅读器逐行读取文本文件并用Java格式化它们

6 个答案: