从一个文件中读取数字并创建一个数组（java）

Question

我无法弄清楚如何将这个带有数字的txt文件放入数组中，我能够读取并打印屏幕，但我需要能够组织数字并删除重复项。这是我的代码看起来像到目前为止

import java.io.BufferedReader; 
import java.io.FileNotFoundException; 
import java.io.FileReader; 
import java.io.IOException; 

public class File { 
public static void main(String[] args) { 
String filename = "C:/input.txt"; 

File rfe = new File(); 
rfe.readFile(filename); 
} 

private void readFile(String name) { 
String input; 

    try (BufferedReader reader = new BufferedReader(new FileReader(name))) { 

    while((input = reader.readLine()) != null) { 
     System.out.format(input); // Display the line on the monitor 
    } 
} 
catch(FileNotFoundException fnfe) { 

} 
catch(IOException ioe) { 

} 
catch(Exception ex) { // Not required, but a good practice 

} 


} 
} 

Answer 1

我会建议使用ArrayList而不是数组。

对于数组，您必须先解析列表并计算行数，然后才能对其进行初始化。 ArrayList更灵活，因为您无需声明将添加多少个值。

import java.io.BufferedReader; 
import java.io.FileNotFoundException; 
import java.io.FileReader; 
import java.io.IOException; 
import java.util.ArrayList; 
import java.util.List; 

public class File { 

private List<Integer> data = new ArrayList<Integer>(); //Create ArrayList 

public static void main(String[] args) { 
    String filename = "C:/input.txt"; 

    File rfe = new File(); 
    rfe.readFile(filename); 
} 

private void readFile(String name) { 
    String input; 

    try (BufferedReader reader = new BufferedReader(new FileReader(name))) { 

     while((input = reader.readLine()) != null) { 
      data.add(Integer.parseInt(input));//Add each parsed number to the arraylist 
      System.out.println(input); // Display the line on the monitor 
     } 
    } 
    catch(FileNotFoundException fnfe) { 

    } 
    catch(IOException ioe) { 

    } 
    catch(Exception ex) { // Not required, but a good practice 
     ex.printstacktrace(); //Usually good for general handling 
    } 

} 
}