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The docs of Java 7 for FileWriter and FileOutputStream shows that the constructor of FileWriter throws IOException, while the constructor of FileOutputStream throws FileNotFoundException.

The reason for both the exceptions is same though. It says,"if the file exists but is a directory rather than a regular file, does not exist but cannot be created, or cannot be opened for any other reason"

If this is the case, then why a specialized exception for FileOutputStream and a general exception for FileWriter is decided by Java creators??

whitehat
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1 Answers1

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  1. FileWriter extends OutputStreamWriter whose constructor throws UnsupportedEncodingException.
  2. If you look at the implementation of FileWriter, it uses FileOutputStream which throws FileNotFoundException.

Because the FileWriter constructor can now throw either of these exceptions, it is declared to throw IOException, which is a common superclass for both exceptions. (Alternatively, it could have been declared to throw two individual exceptions.)

casablanca
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  • FileReader extends InputStreamReader (which constructors may throw UnsupportedCharsetException), but FileReader constructors throw only FileNotFoundException (FileReader constructors call FileInputStream constructors which throw only FileNotFoundException). – Code Complete Feb 24 '18 at 10:58