BufferedReader & BufferedWriter (NIO) – Read & write file (java/example)

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Read Write file IO using BufferedReader & BufferedWriter

  • Given a file, read & write file contents using BufferReader & BufferWriter in java.
  • Use java NIO (Non-Blocking or New IO) feature to perform java IO operations.
  • BufferWriter writes to character based stream & BufferReader reads from character based stream, so as to provide efficient writing/reading of characters, arrays, and strings.
  • We have already discussed similar posts:

Program – read & write file using BufferedReader & BufferedWriter (NIO)

package org.learn.io;
 
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
 
public class BufferReaderWriterNIO {
    public static void main(String[] args) throws IOException {
        writeUsingNIO();   
        readUsingNIO();
    }
 
    private static void writeUsingNIO() throws IOException {
        System.out.println("1. Start writting contents to file - BufferedWriter(NIO)");
        Path path = Paths.get("sampleFile.txt");
        try (BufferedWriter bufferWriter = Files.newBufferedWriter(path)) {
            bufferWriter.write("Soccer");
            bufferWriter.newLine();
            bufferWriter.write("Tennis");
            bufferWriter.newLine();
            bufferWriter.write("Badminton");
            bufferWriter.newLine();
            bufferWriter.write("Hockey");
            bufferWriter.newLine();
        }
        System.out.println("2. Successfully written contents to file - BufferedWriter(NIO)");
    }
     
    private static void readUsingNIO() throws IOException {
        Path path = Paths.get("sampleFile.txt");
        try (BufferedReader bufferedReader = Files.newBufferedReader(path)) {
            String line;
            System.out.println("\n3. Start Reading file using BufferedReader (NIO)");
            while ((line = bufferedReader.readLine()) != null) {
                System.out.println(line);
            }
            System.out.println("4. End reading file using BufferedReader (NIO)");
        }
    }
}

The content of sampleFile.txt is as follows:

BufferWriter BufferReader file NIO operation
Fig 1: Write contents using BufferWriter

Output: Read & write file in java (BufferedReader & BufferedWriter)

1. Start writting contents to file - BufferedWriter(NIO)
2. Successfully written contents to file - BufferedWriter(NIO)
 
3. Start Reading file using BufferedReader (NIO)
Soccer
Tennis
Badminton
Hockey
4. End reading file using BufferedReader (NIO)

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