import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.IOException;
import java.io.File;
import java.io.FileOutputStream;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.channels.FileChannel;

public class IOFileTest {
  public static void main(String[] args) throws IOException{
    
    String line;
//Use a BufferedReader for reading in an entire line from keyboard to the String line.    
    BufferedReader byteReader = new BufferedReader(new InputStreamReader(System.in));
    line = byteReader.readLine();
    System.out.println(line);
    
//Create directory and file objects.
    File myDir = new File("testdir");
    File myFile = new File(myDir, "testfile.txt");
    System.out.println("myDir is " + 
      (myDir.isDirectory() ? "" : "not ") +
      "a directory.");
    System.out.println("myFile is " + 
      (myFile.isFile() ? "" : "not ") +
      "a file.");

//Create physical directory and file.
    System.out.println("Are you ready to create the directory and file?");
    line = byteReader.readLine();
    myDir.mkdir();
    myFile.createNewFile();
    System.out.println("myDir is " + 
      (myDir.isDirectory() ? "" : "not ") +
      "a directory.");
    System.out.println("myFile is " + 
      (myFile.isFile() ? "" : "not ") +
      "a file.");

//Set up for file output.
    FileOutputStream outStream = new FileOutputStream(myFile);
    FileChannel outChannel = outStream.getChannel();
    ByteBuffer outBuf = ByteBuffer.allocate(120);

//Copy line from keyboard to file.
    System.out.println("Enter a line of text:");
    line = byteReader.readLine();
    outBuf.put(line.getBytes());
    outBuf.flip();
    outChannel.write(outBuf);

//Do it again.
    outBuf.clear();
    System.out.println("Enter another line of text:");
    line = byteReader.readLine();
    outBuf.put(line.getBytes());
    outBuf.flip();
    outChannel.write(outBuf);

//Do it again, but output as unicode chars.
    outBuf.clear();
    System.out.println("Enter another line of text:");
    line = byteReader.readLine();
    for(int i = 0; i<line.length();i++)
      outBuf.putChar(line.charAt(i));
    outBuf.flip();
    outChannel.write(outBuf);   

//Output another line as unicode, using a view buffer.
    outBuf.clear();
    System.out.println("Enter another line of text:");
    line = byteReader.readLine();
    CharBuffer cBuf = outBuf.asCharBuffer();
    cBuf.put(line);
    outBuf.position(0);
    outBuf.limit(2*cBuf.position());
    outChannel.write(outBuf);    

    outStream.close();

  }
}