无法通过Java运行命令，但可以通过cmd运行 CreateProcess error=2, The system cannot find the file specified

Question

I am unable to convert my mp3s to wavs for easier data manipulation using Java. I can open a command prompt and copy the exact string stored in s when I debug and this will properly create the wav file. The code is below. I was able to use ffmpeg by building strings this way to split up a few mp3s into separate tracks based on a tracklist. I reinstalled Windows 10, so I'm assuming it has something to do with that. Is there a setting I have to change? Why would it run in the command prompt, but not with Java?

package mp3towav;

import java.io.File;
import java.io.IOException;

public class Mp3towav {

    // mp3 folder
    public static final String MP3FOLDER = "C:\\Users\\Al\\Documents\\Sounds\\PokemonOST\\YellowOST\\MP3";

    public static void main(String[] args) throws IOException {

        // Gets the mp3 files and converts them to wav
        File mp3folder = new File(MP3FOLDER);

        String[] mp3s = mp3folder.list();

        File f;

        String s; 

        for(int i = 0; i < mp3s.length; i++) {
            f = new File(mp3s[i]);
            s = ("ffmpeg -i " + MP3FOLDER + "\\" + f.getName() + " " + (MP3FOLDER + "\\" + f.getName()).replaceAll("MP3", "WAV").replaceAll("mp3", "wav"));
            Runtime.getRuntime().exec(s);
            System.out.println("test");
        }



    }

}

Edit :

So I never got Java to use PATH, but added in the absolute path to the ffmpeg executable in Java.

Answer 1

我不得不添加到 ffmpeg bin 的路径，包括文件名 ffmpeg.exe，而不是让 Java 依赖 Windows 中的 PATH 变量，即使 ffmpeg 在 CMD 窗口中正常工作。