文件中的Java

Question

我不是開放試圖讀取與內容 一個簡單的文本文件input.txt中

Line 1 
Line 2 
Line 3 

但它總是轉到異常並顯示錯誤。

import java.io.*; 
import java.util.*; 

public class Main { 
    public static void main(String args[]){ 

     List<String> text = new ArrayList<String>(); 
     try{ 
      BufferedReader reader = new BufferedReader(new FileReader("input.txt")); 
      for (String line; (line = reader.readLine()) != null;) { 
       text.add(line); 
      } 
      System.out.println(text.size()); //print how many lines read in 
      reader.close(); 
     }catch(IOException e){ 
      System.out.println("ERROR"); 
     } 
    } 
} 

使用Eclipse作爲我的IDE，如果這有所作爲的話。我試過這個代碼http://www.compileonline.com/compile_java_online.php 它運行良好，爲什麼不運行在Eclipse中？

Answer 1

給出完整的文件路徑，如"C:\\folder_name\\input.txt"或將input.txt放在eclipse項目的src目錄中。

Answer 2

public class Main { 
    public static void main(String args[]){ 

     List<String> text = new ArrayList<String>(); 
     try{ 
      BufferedReader reader = new BufferedReader(
        new FileReader("input.txt")); //<< your problem is probably here, 
      //More than likely you have to supply a path the input file. 
      //Something like "C:\\mydir\\input.txt" 
      for (String line; (line = reader.readLine()) != null;) { 
       text.add(line); 
      } 
      System.out.println(text.size()); //print how many lines read in 
      reader.close(); 
     }catch(IOException e){ 
      System.out.println("ERROR"); //This tells you nothing. 
      System.out.println(e.getMessage()); //Do this 
      //or 
      e.printStackTrace(); //this or both 

     } 
    } 
} 

Answer 3

你很可能有一個不好的路徑。考慮這個主要代替：

public class Main { 
    public static void main(String args[]) throws Exception { 

     List<String> text = new ArrayList<String>(); 

     BufferedReader reader = new BufferedReader(new FileReader("input.txt")); 
     for (String line; (line = reader.readLine()) != null;) { 
      text.add(line); 
     } 
     System.out.println(text.size()); //print how many lines read in 
     reader.close(); 
    } 
} 

「拋出異常」此外允許您專注於代碼，並考慮更好的錯誤處理。另外考慮使用File f = new File("input.txt")並使用它，因爲它允許您打印出f.getAbsolutePath()，告訴你它實際上正在查找的文件名。

Answer 4

將input.txt更改爲src\\input.txt解決了問題！ 我想這是因爲當前目錄實際上是其父母的src文件夾，

感謝您的幫助！