OCP OCP Java IO and NIO

Question 1

Which Java class is designed specifically to read character data from a file using a character stream?

Accepted Answer

FileReader

Answer

FileReader is a character stream (Reader subclass) that reads text data from a file, while FileInputStream reads raw bytes.

Question 2

What is the primary benefit of wrapping a FileWriter with a BufferedWriter in Java?

Accepted Answer

It reduces the number of actual write operations through internal buffering

Answer

BufferedWriter wraps another Writer with an internal buffer, batching multiple small writes into fewer, more efficient I/O operations.

Question 3

What exception type must be handled or declared when performing file I/O operations in Java?

Accepted Answer

IOException

Answer

IOException is a checked exception that is the parent of all I/O-related exceptions and must be handled with try-catch or declared in the method signature.

Question 4

Which Java I/O class provides methods like readInt() and readDouble() to read primitive data types from a binary file?

Accepted Answer

DataInputStream

Answer

DataInputStream wraps an InputStream and adds typed read methods for all Java primitive data types, making binary file parsing straightforward.

Question 5

What guarantee does the Java try-with-resources statement provide when used with I/O streams?

Accepted Answer

Streams are automatically closed when the try block exits

Answer

Try-with-resources automatically invokes close() on any AutoCloseable resource declared in the try header when the block completes, normally or exceptionally.

(OCP) Oracle Certified Professional Practice Test

(OCP) Oracle Certified Professional Practice Test

OCP OCP Java IO and NIO