如何捕捉两个文件的FileNotFoundException？

Question

我有两个文本文件，如果找不到文件，我想抛出一个异常。我有一个类FileReader来检查文件是否存在，并且在我的主目录中我尝试捕获异常。

    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
         }

在另一个类中，如果文件丢失，我想捕捉异常。

public class FileIO {

public static void main(String[] args) {

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

如果只缺少一个文件，这将非常有效。但是如果文件1和文件2都缺失，我只捕捉到第一个缺失文件的异常，然后程序结束。我的输出是：

File "file1.txt" is not found.

我如何捕捉两者的异常？我希望它输出：

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

Answer 1

您可以在引发异常之前先构造错误消息。

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