I/O Operations Flashcards
7 cards from real 1Z0-819 practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 I/O Operations flashcards as text
Which `Files` method reads all lines of a text file into a `List` using the default charset?
Answer: Files.readAllLines(path)
`Files.readAllLines(path)` reads all lines into a `List` using UTF-8 by default in Java 11.
What is the key difference between `Files.lines(path)` and `Files.readAllLines(path)`?
Answer: `Files.lines` returns a lazy `Stream` while `readAllLines` loads everything into memory immediately
`Files.lines` is lazy and streams lines on demand, whereas `readAllLines` materializes all lines into a `List` at once.
Which method creates all missing parent directories for a given path in one call?
Answer: Files.createDirectories(path)
`Files.createDirectories` creates the target directory and all missing parents without throwing an error if they already exist.
What does `Path.normalize()` do?
Answer: Removes redundant `.` and `..` elements from the path
`normalize()` eliminates redundant `.` (current directory) and `..` (parent directory) segments without accessing the filesystem.
Which method on `Path` combines the current path with another path segment?
Answer: resolve()
`resolve()` appends the given path to the base path, handling absolute/relative combinations correctly.
What does `Files.isSameFile(path1, path2)` check?
Answer: Whether both paths locate the same file on the filesystem, even via different names or symlinks
`Files.isSameFile` uses the OS to determine if both paths refer to the same inode/file, resolving symlinks.
What happens when you call `Files.delete(path)` on a non-empty directory?
Answer: It throws `DirectoryNotEmptyException`
`Files.delete` will throw `DirectoryNotEmptyException` if the directory still contains entries.