Java Programming

*Hi All,
Im able to convert wav file of PCM audio format to ULAW audio format using the below code,*

import java.io.IOException;
import java.io.File;
import javax.sound.sampled.AudioFileFormat;
import javax.sound.sampled.AudioFormat;
import javax.sound.sampled.AudioInputStream;
import javax.sound.sampled.AudioSystem;

public class UlawEncoder{
	public static void main(String[] args){
		File	pcmFile = new File(args[0]);
		File	ulawFile = new File(args[1]);
		AudioInputStream	ais = null;
		
		try{
			ais = AudioSystem.getAudioInputStream(pcmFile);
		}catch (Exception e){
			e.printStackTrace();
		}
		
		AudioFormat.Encoding	targetEncoding = AudioFormat.Encoding.ULAW;
		AudioInputStream	ulawAudioInputStreamAIS = AudioSystem.getAudioInputStream(targetEncoding, ais);
		AudioFileFormat.Type	fileType = AudioFileFormat.Type.WAVE;
		int	nWrittenFrames = 0;
		try{
			nWrittenFrames = AudioSystem.write(ulawAudioInputStreamAIS, fileType, ulawFile);
		}catch (IOException e){
			e.printStackTrace();
		}
	}
}

And now i want to make the Audio Sample Rate to 8000 and i have done like the code below,

		
		try{
			ais = AudioSystem.getAudioInputStream(pcmFile);
			format = ais.getFormat();
			
			format = new AudioFormat(
                    AudioFormat.Encoding.ULAW,
                    8000.0f,
                    format.getSampleSizeInBits(),
					format.getChannels(),
                    format.getFrameSize(),
                    format.getFrameRate(),
                    true);			
				ais = AudioSystem.getAudioInputStream(format, ais);
			
		}catch (Exception e){
			e.printStackTrace();
		}
		
		AudioInputStream	AudioInputStreamAIS = AudioSystem.getAudioInputStream(format, ais);
		AudioFileFormat.Type	fileType = AudioFileFormat.Type.WAVE;
		int	nWrittenFrames = 0;
		try{
			nWrittenFrames = AudioSystem.write(AudioInputStreamAIS, fileType, ulawFile);
		}catch (IOException e){
			e.printStackTrace();
		}

im getting Exception

java.lang.IllegalArgumentException: Unsupported conversion: ULAW 8000.0 Hz, 16 bit, mono, 2 bytes/fr
ame, 11025.0 frames/second,  from PCM_SIGNED 11025.0 Hz, 16 bit, mono, 2 bytes/frame, little-endian
        	
	

How can i make the audio sample rate to 8000. please help.
Thanks in advance.