如何捕獲兩個文件的FileNotFoundException？

Question

我有兩個文本文件，我想拋出一個異常，如果沒有找到文件。我有一個類FileReader，檢查文件是否存在，並在我的主要我試圖捕捉異常。

public FileReader() throws FileNotFoundException { 
     super(); 
     File file1 = new File("file1.txt"); 
     File file2 = new File("file2.txt"); 

     //Throws the FileNotFoundException if the files aren't found 
     if (!file1.exists()) { 
      throw new FileNotFoundException("File \"file1.txt\" was not found."); 
     } else { 
     //do something 
     } 
     if (!file2.exists()) { 
      throw new FileNotFoundException("File \"file2.txt\" was not found."); 
     } else { 
     //do something 
     } 

在另一個類中，我想捕捉異常如果文件丟失。

public class FileIO { 

public static void main(String[] args) { 

    try { 
     //do stuff 
    } catch(FileNotFoundException e) { 
     System.out.println(e.getMessage()); 
    } 

如果只有一個文件丟失，這很有用。但是，如果file1和file2都丟失了，我只會捕獲第一個丟失文件的異常，然後程序結束。我的輸出是：

File "file1.txt" is not found. 

我該如何捕捉兩者的例外？我想要它輸出：

File "file1.txt" is not found. 
File "file2.txt" is not found. 

Answer 1

您可以在拋出異常之前構造錯誤消息。

public FileReader() throws FileNotFoundException { 
    super(); 
    File file1 = new File("file1.txt"); 
    File file2 = new File("file2.txt"); 

    String message = ""; 

    if (!file1.exists()) { 
     message = "File \"file1.txt\" was not found."; 
    } 
    if (!file2.exists()) { 
     message += "File \"file2.txt\" was not found."; 
    } 

    //Throws the FileNotFoundException if the files aren't found 
    if (!messag.isEmpty()) { 
     throw new FileNotFoundException(message); 
    } 

    //do something