Query the position using the SeekableByteChannel - Java File Path IO

Java examples for File Path IO:File Channel

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Description

Query the position using the SeekableByteChannel

Demo Code

import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.SeekableByteChannel;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.StandardOpenOption;

public class Main {

  public static void main(String[] args) throws IOException {
    int bufferSize = 8;
    Path path = Paths.get("/home/docs/users.txt");
    ////from  w w w.  j  a v  a2s. com
    final String newLine = System.getProperty("line.separator");
    try (SeekableByteChannel sbc = Files.newByteChannel(path, StandardOpenOption.WRITE)) {
      ByteBuffer buffer;
      long position = sbc.size();
      sbc.position(position);
      System.out.println("Position: " + sbc.position());

      buffer = ByteBuffer.wrap((newLine + "Paul").getBytes());
      sbc.write(buffer);
      System.out.println("Position: " + sbc.position());
      buffer = ByteBuffer.wrap((newLine + "Carol").getBytes());
      sbc.write(buffer);
      System.out.println("Position: " + sbc.position());
      buffer = ByteBuffer.wrap((newLine + "Fred").getBytes());
      sbc.write(buffer);
      System.out.println("Position: " + sbc.position());
    }

  }

}

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