Java.Streams.What subclasses of the Writer class do you know, what are they for?

📘 Writer Overview

• Writer is an abstract class in java.io for writing character data.
• It’s the counterpart to OutputStream, but designed for writing text (characters and strings) rather than raw bytes.

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🔽 Common Subclasses of Writer

Subclass	Description
BufferedWriter	Adds buffering for efficient writing of characters, arrays, and strings.
OutputStreamWriter	Bridges character streams to byte streams using a specified charset.
FileWriter	Convenience subclass of OutputStreamWriter to write to files (uses default charset).
CharArrayWriter	Writes to an in-memory character array, similar to StringBuilder.
StringWriter	Writes to an internal StringBuffer.
PipedWriter	Used with PipedReader for inter-thread communication.
PrintWriter	Writes formatted representations of objects (like System.out) and supports print() and println().
FilterWriter	Abstract class for decorating other writer streams.

✅ Quick Examples

1. BufferedWriter

BufferedWriter writer = new BufferedWriter(new FileWriter("output.txt"));
writer.write("Hello Buffered Writer");
writer.newLine();
writer.close();

2. OutputStreamWriter

OutputStreamWriter writer = new OutputStreamWriter(new FileOutputStream("output.txt"), "UTF-8");
writer.write("Text with UTF-8 encoding");
writer.close();

3. FileWriter

FileWriter writer = new FileWriter("file.txt");
writer.write("Hello FileWriter");
writer.close();

4. StringWriter

StringWriter sw = new StringWriter();
sw.write("Hello StringWriter");
System.out.println(sw.toString());

5. PrintWriter

PrintWriter writer = new PrintWriter("log.txt");
writer.println("Log entry: " + new Date());
writer.close();

6. CharArrayWriter

CharArrayWriter caw = new CharArrayWriter();
caw.write("Hello in memory");
System.out.println(caw.toString());
caw.close();

🧵 Summary Table

Writer Subclass	Purpose
BufferedWriter	Efficient character output
OutputStreamWriter	Converts characters to bytes (with charset)
FileWriter	Writes characters to a file
CharArrayWriter	Writes to in-memory character array
StringWriter	Writes to string buffer (in-memory)
PipedWriter	Sends characters to another thread
PrintWriter	Provides formatted output, like System.out
FilterWriter	Base for decorators