[IO-810] Javadoc in FileUtils does not reflect code for thrown exceptions

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.12.0, 2.13.0
• Fix Version/s: 2.15.0
• Component/s: Utilities
• Assignee: Unassigned
• Reporter: Gregor Dschung
• Created: 27/Sep/23 07:51
• Updated: 30/Sep/23 11:58
• Resolved: 28/Sep/23 18:24

Description

The JavaDoc of FileUtils#readFileToString(...) is stating that a FileNotFoundException is thrown if the file doesn't exist. This isn't true with version 2.12 and above, including the current 2.14 snapshot, where a NoSuchFileException is thrown. I haven't tested, but I guess that other methods like FileUtils#readFileToByteArray(...) are affected, too, as the exception is coming via Files#newByteChannel(...).

Root cause seems to be, like in IO-800, this commit from 2021, where openInputStream(file) (which is calling 
new FileInputStream(file) from java.io) is replaced by Files.newInputStream(file.toPath()) from java.nio.

I'm unsure if just the JavaDoc should be updated or the old behavior be restored: I noticed the bug because we catch a FileNotFoundException, which doesn't work for 2.12 and above.

Old Stacktrace

java.io.FileNotFoundException: doesnt-exist.txt (No such file or directory)
	at java.base/java.io.FileInputStream.open0(Native Method) ~[na:na]
	at java.base/java.io.FileInputStream.open(FileInputStream.java:219) ~[na:na]
	at java.base/java.io.FileInputStream.<init>(FileInputStream.java:157) ~[na:na]
	at org.apache.commons.io.FileUtils.openInputStream(FileUtils.java:2388) ~[commons-io-2.11.0.jar:2.11.0]
	at org.apache.commons.io.FileUtils.readFileToString(FileUtils.java:2506) ~[commons-io-2.11.0.jar:2.11.0]
	at org.apache.commons.io.FileUtils.readFileToString(FileUtils.java:2526) ~[commons-io-2.11.0.jar:2.11.0]

New Stacktrace

java.nio.file.NoSuchFileException: doesnt-exist.txt
	at java.base/sun.nio.fs.UnixException.translateToIOException(UnixException.java:92) ~[na:na]
	at java.base/sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:111) ~[na:na]
	at java.base/sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:116) ~[na:na]
	at java.base/sun.nio.fs.UnixFileSystemProvider.newByteChannel(UnixFileSystemProvider.java:219) ~[na:na]
	at java.base/java.nio.file.Files.newByteChannel(Files.java:371) ~[na:na]
	at java.base/java.nio.file.Files.newByteChannel(Files.java:422) ~[na:na]
	at java.base/java.nio.file.spi.FileSystemProvider.newInputStream(FileSystemProvider.java:420) ~[na:na]
	at java.base/java.nio.file.Files.newInputStream(Files.java:156) ~[na:na]
	at org.apache.commons.io.FileUtils.lambda$readFileToString$12(FileUtils.java:2616) ~[commons-io-2.13.0.jar:2.13.0]
	at org.apache.commons.io.IOUtils.toString(IOUtils.java:3177) ~[commons-io-2.13.0.jar:2.13.0]
	at org.apache.commons.io.IOUtils.toString(IOUtils.java:3152) ~[commons-io-2.13.0.jar:2.13.0]
	at org.apache.commons.io.FileUtils.readFileToString(FileUtils.java:2616) ~[commons-io-2.13.0.jar:2.13.0]
	at org.apache.commons.io.FileUtils.readFileToString(FileUtils.java:2599) ~[commons-io-2.13.0.jar:2.13.0]

Issue Links

• is related to: IO-800 Fix back-incompatible change for PathUtils.deleteDirectory(): throw NoSuchFileException instead of IllegalArgumentException
• links to: GitHub Pull Request #486