微信小程序录音文件格式silk遇到的问题及解决方法

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import com.qcloud.Utilities.Base64;
public class Base64Webm {
 public static void readTxtFile(String filePath) {
 try {
 String encoding = "utf-8";
 File file = new File(filePath);
 if (file.isFile() && file.exists()) { // 判断文件是否存在
 InputStreamReader read = new InputStreamReader(new FileInputStream(file), encoding);// 考虑到编码格式
 BufferedReader bufferedReader = new BufferedReader(read);
 StringBuilder lineTxt = new StringBuilder();
 String line = null;
 while ((line = bufferedReader.readLine()) != null) {
  lineTxt.append(line);
 }
 read.close();
 
 String olddata = lineTxt.toString();
 olddata = olddata.replace("data:audio/webm;base64,", "");
 System.out.println(olddata);
 
   try { 
   
   File webmFile = new File("D:\\project\\liulei\\Doc\\互动直播室\\微课网页开发\\silk2mp3\\caole.webm");
   byte[] bt = Base64.decode(olddata) ;
    FileOutputStream in = new FileOutputStream(webmFile); 
    try { 
     in.write(bt, 0, bt.length); 
     in.close(); 
     // boolean success=true; 
     // System.out.println("写入文件成功"); 
    } catch (IOException e) { 
     // TODO Auto-generated catch block 
     e.printStackTrace(); 
    } 
   } catch (FileNotFoundException e) { 
    // TODO Auto-generated catch block 
    e.printStackTrace(); 
   } 
 } else {
 System.out.println("找不到指定的文件");
 }
 } catch (Exception e) {
 System.out.println("读取文件内容出错");
 e.printStackTrace();
 }
 }
 
 public static void main(String[] args) {
 readTxtFile("D:\\project\\liulei\\Doc\\互动直播室\\微课网页开发\\silk2mp3\\liulie.silk");
 }
}