What throws an IOException in Java?

Assume you were:

  1. Reading a network file and got disconnected.
  2. Reading a local file that was no longer available.
  3. Using some stream to read data and some other process closed the stream.
  4. Trying to read/write a file, but don't have permission.
  5. Trying to write to a file, but disk space was no longer available.

There are many more examples, but these are the most common, in my experience.


In general, I/O means Input or Output. Those methods throw the IOException whenever an input or output operation is failed or interpreted. Note that this won't be thrown for reading or writing to memory as Java will be handling it automatically.

Here are some cases which result in IOException.

  • Reading from a closed inputstream
  • Try to access a file on the Internet without a network connection