用java 写一个wav 转mp3的程序

要将 WAV 转换为 MP3，需要使用第三方库。以下是使用 LAME 库进行转换的 Java 代码示例：

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import javax.sound.sampled.AudioFormat;
import javax.sound.sampled.AudioInputStream;
import javax.sound.sampled.AudioSystem;

import org.apache.commons.io.FileUtils;
import org.apache.commons.io.FilenameUtils;

import javazoom.jl.converter.Converter;
import javazoom.jl.decoder.JavaLayerException;

public class WavToMp3Converter {

    public static void main(String[] args) throws IOException, JavaLayerException {
        String inputFilePath = "path/to/input/wav/file.wav";
        String outputFilePath = "path/to/output/mp3/file.mp3";
        convertWavToMp3(inputFilePath, outputFilePath);
    }

    public static void convertWavToMp3(String inputFilePath, String outputFilePath)
            throws IOException, JavaLayerException {
        File inputFile = new File(inputFilePath);
        File outputFile = new File(outputFilePath);

        // Copy the input file to a temporary file
        File tempFile = new File(
                FilenameUtils.getFullPath(outputFile.getAbsolutePath()) + "temp_" + outputFile.getName());
        FileUtils.copyFile(inputFile, tempFile);

        // Open the input and output streams
        InputStream inputStream = new FileInputStream(tempFile);
        OutputStream outputStream = new FileOutputStream(outputFile);

        // Convert the WAV file to MP3
        AudioInputStream audioInputStream = AudioSystem.getAudioInputStream(inputStream);
        AudioFormat sourceFormat = audioInputStream.getFormat();
        AudioFormat targetFormat = new AudioFormat(
                AudioFormat.Encoding.PCM_SIGNED, sourceFormat.getSampleRate(), 16,
                sourceFormat.getChannels(), sourceFormat.getChannels() * 2, sourceFormat.getSampleRate(),
                false);
        AudioInputStream pcmAudioInputStream = AudioSystem.getAudioInputStream(targetFormat, audioInputStream);
        Converter converter = new Converter();
        converter.convert(pcmAudioInputStream, outputStream);

        // Clean up
        inputStream.close();
        outputStream.close();
        audioInputStream.close();
        pcmAudioInputStream.close();
        FileUtils.deleteQuietly(tempFile);
    }

}

请注意，这个示例代码依赖于 LAME 库，可以从以下网址下载：http://www.java2s.com/Code/Jar/l/Downloadlame070jar.htm

此外，还需要导入 Apache Commons IO 库。可以从以下网址下载：https://commons.apache.org/proper/commons-io/download_io.cgi