java如何检查文件是否存在并打开它？

问题描述：

如何检查文件是否存在并打开它？

how to check if file exists and open it?

if(file is found)
{
    FileInputStream file = new FileInputStream("file");
}

答

File.isFile 将告诉您文件存在且不是目录。

File.isFile will tell you that a file exists and is not a directory.

请注意，您的检查和尝试之间的文件可能会被删除打开它，该方法不会检查当前用户是否具有读取权限。

Note, that the file could be deleted between your check and your attempt to open it, and that method does not check that the current user has read permissions.

File f = new File("file");
if (f.isFile() && f.canRead()) {
  try {
    // Open the stream.
    FileInputStream in = new FileInputStream(f);
    // To read chars from it, use new InputStreamReader
    // and specify the encoding.
    try {
      // Do something with in.
    } finally {
      in.close();
    }
  } catch (IOException ex) {
    // Appropriate error handling here.
  }
}

java如何检查文件是否存在并打开它？

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