Java File I/O Streams Flashcards

File I/O API Overview

• The File I/O API is represented by java.io.File, which manages file operations.
• URI stands for Uniform Resource Identifier; an example is file c://c:/data.txt.

File Class Functionality

• The File class does not handle data input or output processes.
• Provides metadata about files and directories.

Streams in Java

• Streams represent sequences of data.
• Input streams read data from various sources, not limited to files.
• Output streams write data to various sources, also not limited to files.

Types of Streams

• Types of streams in Java I/O include:
  • Byte stream
  • Character stream
  • Buffered streams
  • Object streams
  • Line-oriented I/O

Stream Characteristics

• Byte streams offer a low-level API for handling data in bytes.
• Character streams provide a higher-level API that converts data to text format automatically.
• Buffered streams enhance performance by minimizing direct OS I/O operations, utilizing internal buffers.
• Object streams read and write Java objects to files; objects must implement java.io.Serializable.

File Access Methods

• Sequential file access means data cannot be modified in the middle without rewriting the entire file.
• Random file access allows direct access to data at any position in the file.

Random Access File Class

• The java.io.RandomAccessFile class enables random file access, allowing binary read and write operations.

File Types and Serialization

• Binary files store data in binary format and can be distinguished from text files.
• Serialization facilitates writing entire objects to streams and retrieving them later.

Input/Output Concepts

• The acronym I/O stands for Input/Output.
• Character streams utilize java.io.FileReader and java.io.FileWriter for I/O operations.
• Byte streams rely on java.io.FileInputStream and java.io.FileOutputStream.

Java File Representation

• Java treats each file as a sequential stream of bytes.
• Character streams process data as sequences of characters, with each character representing 2 bytes.
• Byte streams handle data in binary format, where a char is 2 bytes, int is 4 bytes, and double is 8 bytes.

Stream Objects and Buffered Streams

• Java creates three standard stream objects upon opening a file: System.in, System.out, and System.err.
• Buffered stream APIs for character streams include java.io.BufferedReader and java.io.BufferedWriter.
• Buffered stream APIs for byte streams consist of java.io.BufferedInputStream and java.io.BufferedOutputStream.

Buffer Flushing and Console Management

• The flush method clears the buffer in buffered output streams.
• Standard streams supported by Java include System.in, System.out, and System.err.
• The console provides a true character stream, while the standard streams provide byte streams.
• The console is invoked using System.console(), returning null if unavailable.

Console API and Password Handling

• The Console API is represented by java.io.Console.
• The readPassword() method in the Console class supports secure password entry.

Data Streams

• Data streams are implemented using java.io.DataInputStream and java.io.DataOutputStream.
• Data Input Streams support various data types, enabling type-specific read and write operations.

Test your knowledge on Java's File I/O API with these flashcards. Each card highlights key concepts and terminology essential for understanding file operations in Java. Ideal for students and developers looking to strengthen their Java programming skills.