java提取wav的频谱

以下是Java提取wav的频谱的示例代码：

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

public class WavSpectrumExtractor {
    
    public static void main(String[] args) {
        // 设置wav文件路径
        String filePath = "path/to/wav/file.wav";
        
        try {
            // 读取wav文件
            File file = new File(filePath);
            AudioInputStream audioInputStream = AudioSystem.getAudioInputStream(file);
            
            // 获取音频数据的格式
            AudioFileFormat audioFileFormat = AudioSystem.getAudioFileFormat(file);
            AudioFormat audioFormat = audioFileFormat.getFormat();
            
            // 获取音频数据的长度和采样率
            int numBytes = (int) file.length();
            int sampleRate = (int) audioFormat.getSampleRate();
            
            // 将音频数据读入缓冲区
            byte[] audioBytes = new byte[numBytes];
            audioInputStream.read(audioBytes);
            
            // 将缓冲区中的音频数据转换为double类型的数组
            int[] audioData = new int[numBytes / 2];
            for (int i = 0; i < audioData.length; i++) {
                audioData[i] = ((audioBytes[i * 2 + 1] & 0xff) << 8) + (audioBytes[i * 2] & 0xff);
            }
            
            // 计算FFT
            DoubleFFT_1D fft = new DoubleFFT_1D(audioData.length);
            double[] fftData = new double[audioData.length * 2];
            for (int i = 0; i < audioData.length; i++) {
                fftData[i * 2] = audioData[i];
                fftData[i * 2 + 1] = 0;
            }
            fft.realForward(fftData);
            
            // 计算频谱
            double[] freqData = new double[audioData.length / 2];
            for (int i = 0; i < freqData.length; i++) {
                double real = fftData[i * 2];
                double imag = fftData[i * 2 + 1];
                freqData[i] = Math.sqrt(real * real + imag * imag);
            }
            
            // 输出频谱
            for (int i = 0; i < freqData.length; i++) {
                System.out.println((i * sampleRate / audioData.length) + "Hz: " + freqData[i]);
            }
            
            audioInputStream.close();
        } catch (UnsupportedAudioFileException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

这个示例代码使用了JTransforms库中的DoubleFFT_1D类来计算FFT。在计算FFT之前，需要将音频数据转换为double类型的数组，并将其传递给DoubleFFT_1D对象的realForward()方法。计算FFT之后，需要计算频谱并输出结果。