Problem : Writting Data Into File Using Channel

[kayanaat sidiqui]

Hi,

I am using the following code for writting data in to file --

 import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.FileNotFoundException;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;

public class MainClass {
  public static void main(String[] args) {
    String phrase = new String("test\n");

    File aFile = new File("test.txt");   
    FileOutputStream outputFile = null;  
    try {
      outputFile = new FileOutputStream(aFile, true);
      System.out.println("File stream created successfully.");
    } catch (FileNotFoundException e) {
      e.printStackTrace(System.err);
    } 

    FileChannel outChannel = outputFile.getChannel();
    
    ByteBuffer buf = ByteBuffer.allocate(1024);
    System.out.println("New buffer:           position = " + buf.position()
                       + "\tLimit = " + buf.limit() + "\tcapacity = "
                       + buf.capacity());

    // Load the data into the buffer
    for (char ch : phrase.toCharArray()) {
      buf.putChar(ch);
    }
    System.out.println("Buffer after loading: position = " + buf.position()
                       + "\tLimit = " + buf.limit() + "\tcapacity = "
                       + buf.capacity());
    buf.flip();
    System.out.println("Buffer after flip:    position = " + buf.position() 
                       + "\tLimit = " + buf.limit() + "\tcapacity = " 
                       + buf.capacity());

    try {
      outChannel.write(buf);
      outputFile.close();
      System.out.println("Buffer contents written to file.");
    } catch (IOException e) {
      e.printStackTrace(System.err);
    }
  }
}
   

but the output file is as follows--

t e s t []

that is output file is having space in between each letter and unable to identify the new line character.

Could you please tell me where m i doing wrong?

Is there any other way to write and/or append data to a file?

Thanks,
Kaya.

[Rob Spoor]

http://faq.javaranch.com/java/UseCodeTags, don't quote text. I've changed it for you, see how much better that looks.

I've tried your code, and the characters are written using the big-endian Unicode charset (UTF-16BE). That's because ByteBuffer.putChar always uses two bytes for a character.

You should try using a different Charset, and then encode the string instead:

Charset charset = Charset.defaultCharset(); // or perhaps Charset.forName("ASCII"), Charset.forName("UTF-8")
ByteBuffer buf = charset.encode(phrase);

[Ravikanth Boorugadda]

The file is getting written with Unicode characters. Use any editor which supports unicode to read the file. I tried with textpad, it is working fine.

[kayanaat sidiqui]

Thanks a lot Rob for your precious comments and solution. It helps a lot.

Also Thanks to Ravikanth.