即使文件存在，Java FileNotFoundException也是如此 [英] Java FileNotFoundException even though file exists

问题描述

我正在尝试阅读位于C：\ Users \Siddharth \Documents\aarti \yeh_vidhi_mangal.txt的文件。以下代码表示文件存在

I am trying to read a file located at "C:\Users\Siddharth\Documents\aarti\yeh_vidhi_mangal.txt". Following code indicates that file exists

String filename = "C:\\Users\\Siddharth\\Documents\\aarti\\yeh_vidhi_mangal.txt";
        File file = new File(filename);
        System.out.println(file.exists());

但是当我尝试使用

FileInputStream in = new FileInputStream(file);

a FileNotFoundException 被抛出。这是因为访问被拒绝了吗？我检查了文件权限，他们没事。

a FileNotFoundException is thrown. Is this because access is denied? I checked file permissions and they are fine.

我也尝试过没有eclipse的工作。从命令行：

I have also tried working without eclipse. from the command line:

 C:\Users\Siddharth\workspace\file_io_test\src>javac Foo.java
    Foo.java:16: error: unreported exception FileNotFoundException; must be caught o
    r declared to be thrown
                    FileInputStream in = new FileInputStream(file);
                                         ^
    1 error

推荐答案

根据 FileInputStream ，如果指定的文件不存在，则是目录而不是常规文件，或由于某些其他原因无法打开阅读然后抛出FileNotFoundException。 （强调我的）文件可能被另一个应用程序锁定或使用。

According to the documentation for FileInputStream, "If the named file does not exist, is a directory rather than a regular file, or for some other reason cannot be opened for reading then a FileNotFoundException is thrown." (emphasis mine) The file may be locked or in use by another application.

file.canRead（）返回？

现在您已经用更多数据更新了问题，我可以看到您误解了错误信息。错误是您正在调用抛出某种类型的异常的方法，并且您没有正确报告或处理异常。您可以为 FileNotFoundException 添加 try / catch 或者在方法声明中添加 throws ，声明可以抛出 FileNotFoundException 。

Now that you've updated your question with more data, I can see that you are misinterpreting the error message. The error is that you are calling a method which throws a certain type of exception and you are not properly reporting or handling the exception. You can either add a try / catch for FileNotFoundException or add a throws to your method declaration which states that FileNotFoundException can be thrown.

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