OutputStreamWriter is a bridge from character streams to byte streams. It encodes character data into bytes using a specified charset and writes them to an underlying byte stream (like FileOutputStream,Socket.getOutputStream()).
It is typically used when you need to write character data to a destination that only supports byte streams.
Commonly Used Constructors and Methods
Simple Program: Writing Characters to File
Write a string to a file using OutputStreamWriter and ensure proper character encoding (UTF-8).
import java.io.*;
public class OutputStreamWriterSimpleDemo {
public static void main(String[] args) {
try (OutputStreamWriter osw = new OutputStreamWriter(new FileOutputStream("output_utf8.txt"), "UTF-8")) {
osw.write("Hello from OutputStreamWriter!\n");
osw.write("This supports UTF-8 encoding.");
System.out.println("Data written successfully to output_utf8.txt");
} catch (IOException e) {
e.printStackTrace();
}
}
}Problem Statement:
LotusJavaPrince is developing a logging system for an international banking application. Mahesh suggests logging messages in different languages (e.g., English, Hindi, Japanese) to a UTF-8 encoded file using OutputStreamWriter.
import java.io.*;
public class MultilingualLogger {
public static void main(String[] args) {
String[] messages = {
"English: Welcome to the system.",
"Hindi: स्वागत है सिस्टम में।",
"Japanese: システムへようこそ。"
};
try (OutputStreamWriter writer = new OutputStreamWriter(
new FileOutputStream("multilingual_log.txt", true), "UTF-8")) {
for (String msg : messages) {
writer.write(msg + "\n");
}
System.out.println("Multilingual log written successfully.");
} catch (IOException e) {
e.printStackTrace();
}
}
}
The OutputStreamWriter class is a powerful and essential tool in Java’s I/O framework for writing character data to byte-oriented streams. It acts as a bridge between character streams and byte streams, making it indispensable for applications that need to handle internationalization or write character data to files, sockets, or other byte-based outputs.