如何在自己的程序中使用下载的Github库？

Question

我正在编写一个程序，当给定.wav文件时会绘制波形，但我也希望它也适用于.mp3。由于java.sound软件包不支持.mp3文件，因此我找到了一个github程序，该程序将mp3文件转换为.wav文件。我下载了项目并得到了这个：

现在该项目中有一个我特别感兴趣的类，那就是WaveConverter类。这非常简单，并要求输入.mp3文件和要将其转换为什么的输出。它是这样的：

package org.mp3transform.wav;

import java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;

import org.mp3transform.Bitstream;
import org.mp3transform.Decoder;
import org.mp3transform.Header;

public class WavConverter extends Decoder {
    public static void main(String[] args) throws Exception {
    String in = "test.mp3";
    String out = "out.wav";
    for (int i = 0; i < args.length; i++) {
        if ("-in".equals(args[i])) {
            in = args[++i];
        } else if ("-in".equals(args[i])) {
            out = args[++i];
        } else {
            System.out.println("Options: -in <input.mp3> -out <output.wav>");
        }
    }
    WavConverter.convert(in, out);
}

private static void convert(String sourceFileName, String destFileName)
        throws IOException {
    System.out.println(sourceFileName);
    InputStream fileIn = new FileInputStream(sourceFileName);
    BufferedInputStream in = new BufferedInputStream(fileIn, 128 * 1024);
    convert(in, destFileName);
    in.close();
}

private static void convert(InputStream sourceStream, String destFileName)
        throws IOException {
    int frameCount = Integer.MAX_VALUE;
    WavConverter decoder = new WavConverter();
    Bitstream stream = new Bitstream(sourceStream);
    frameCount = Integer.MAX_VALUE;
    try {
        for (int frame = 0; frame < frameCount; frame++) {
            Header header = stream.readFrame();
            if (header == null) {
                break;
            }
            if (decoder.channels == 0) {
                int channels = (header.mode() == Header.MODE_SINGLE_CHANNEL) ? 1
                        : 2;
                int freq = header.frequency();
                decoder.initOutputBuffer(channels, freq, destFileName);
            }
            decoder.decodeFrame(header, stream);
            stream.closeFrame();
        }
    } finally {
        decoder.close();
    }
}

private short[] buffer;
private WaveFileWriter outWave;

public void initOutputBuffer(int numberOfChannels, int freq, String fileName)
        throws IOException {
    super.initOutputBuffer(null, numberOfChannels);
    buffer = new short[BUFFER_SIZE];
    for (int i = 0; i < numberOfChannels; ++i) {
        bufferPointer[i] = (short) i;
    }
    outWave = new WaveFileWriter(fileName, freq, (short) 16,
            (short) numberOfChannels);
}

public void appendSamples(int channel, double[] f) {
    int p = bufferPointer[channel];
    for (int i = 0; i < 32; i++) {
        double sample = f[i];
        short s = ((sample > 32767.0f) ? 32767
                : ((sample < -32768.0f) ? -32768 : (short) sample));
        buffer[p] = s;
        p += 2;
    }
    bufferPointer[channel] = p;
}    

public void writeBuffer() throws IOException {
    outWave.writeData(buffer, bufferPointer[0]);
    for (int i = 0; i < channels; ++i) {
        bufferPointer[i] = i;
    }
 }

 public void close() throws IOException {
    outWave.close();
 }
}

但是，我的问题是我继续获得第50行的FileNotFoundException，这是下面的代码行：

InputStream fileIn =新的FileInputStream（sourceFileName）;

由于某种原因，该程序无法找到我的test.mp3文件，尽管从这张照片中可以看出，它显然在同一目录中：

为什么会这样？有没有更好的方法来使用github项目中的类？我真的很困惑，很乐意提供帮助。谢谢。

Answer 1

当您看到类WavConverter实际上只是文件中随后定义的静态方法的实现时，这并不令人感到惊讶。采取所需的方法，将实现留在后面。