Java I/O API and Securing Applications →hardMultiple SelectObjective-mapped

1Z0-829 Java I/O API and Securing Applications Practice Question

Which THREE are valid ways to read the contents of a text file into a String in Java?

⚠ Common exam trap

Many candidates confuse `Files.readAllLines()` (which returns a `List`) with `Files.readString()` (which returns a `String`), or assume `FileReader` has a `readString()` method when it does not.

Answer choices

Why each option matters

Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.

Correct answer & explanation

✓

String content = Files.readString(Path.of("file.txt"));

`Files.readString()` (introduced in Java 11) reads the entire content of a text file into a `String` in one call, handling charset encoding (default UTF-8) and closing the file automatically. It is the simplest and most direct method for this task.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

✓
String content = Files.readString(Path.of("file.txt"));
Why this is correct
Files.readString() reads entire file into a String.
✗
String content = new FileReader("file.txt").readString();
Why it's wrong here
FileReader does not have readString() method.
✗
String content = Files.readAllLines(Path.of("file.txt"));
Why it's wrong here
readAllLines returns List<String>, not String.
✓
String content = new Scanner(new File("file.txt")).useDelimiter("\\Z").next();
Why this is correct
Scanner with delimiter \\Z reads entire file content as one token.
✓
String content = Files.lines(Path.of("file.txt")).collect(Collectors.joining("\n"));
Why this is correct
Files.lines() returns a stream of lines, then joining combines them.

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1Z0-829 Java I/O API and Securing Applications Practice Question

Why each option matters

Option-by-option breakdown

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