如何从目录的文件中读取数据

Question

public class FIlesInAFolder { 

     private static BufferedReader br; 

     public static void main(String[] args) throws IOException { 
      File folder = new File("C:/filesexamplefolder"); 
      FileReader fr = null; 

      if (folder.isDirectory()) { 
       for (File fileEntry : folder.listFiles()) { 
        if (fileEntry.isFile()) { 
         try { 
          fr = new FileReader(folder.getAbsolutePath() + "\\" + fileEntry.getName()); 
          br = new BufferedReader(fr); 
System.out.println(""+br.readLine()); 
         } 
         catch (FileNotFoundException e) { 
          e.printStackTrace(); 
         } 
         finally { 
          br.close(); 
          fr.close(); 
         } 
        } 
       } 
      } 
     } 
    } 

如何从目录的第一个文件打印第一个单词，从第二个文件打印第二个单词并从同一个目录的第三个文件打印第三个单词。

i am able to open directory and print the line from each file of the directory, 
but tell me how to print the first word from first file and second word from second file and so on . . 

Answer 1

像下面这样的东西会从第一个文件中读出第一个字，从第二个文件中读取第二个字，从第n个文件中读取第n个字。您可能需要做一些额外的工作来提高代码的稳定性。

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

public class SOAnswer { 

    private static void printFirst(File file, int offset) throws FileNotFoundException, IOException { 

     FileReader fr = new FileReader(file); 
     BufferedReader br = new BufferedReader(fr); 

     String line = null; 
     while ((line = br.readLine()) != null) { 
      String[] split = line.split(" "); 
      if(split.length >= offset) { 
       String targetWord = split[offset]; 
      } 
      // we do not care if files are read that do not match your requirements, or 
      // for reading complete files as you only care for the first word 
      break; 
     } 

     br.close(); 
     fr.close(); 
    } 

    public static void main(String[] args) throws Exception { 
     File folder = new File(args[0]); 
     if(folder.isDirectory()) { 
      int offset = 0; 
      for(File fileEntry : folder.listFiles()) { 
       if(fileEntry.isFile()) { 
        printFirst(fileEntry, offset++); // handle exceptions if you wish 
       } 
      } 
     } 
    } 
}