跟着教程学习MP3播放器编写，遇到奇怪事，扩展名为MP3、jpg、gif的都可以下载，唯独lrc的下载总失败，终于找到原因！

首先问题描述！
跟着教程学习MP3播放器编写，实现了从自己搭建的服务器下载MP3文件，并播放的功能，但是遇到一个问题，我的下载程序的代码在运行时，下载a01.mp3、a01.jpg、a01.gif、a01.txt等文件都可以正常下载，唯独下载a01.lrc文件时出现异常，下载失败。但如果把a01.lrc文件名改为a01.txt，就可以下载成功，实在找不出问题原因。后来经论坛兄弟帮忙，终于找到解决方法！

代码如下：
负责下载的线程的代码：mp3Name的值赋为01.mp3、a01.jpg、a01.gif、a01.txt等文件都可以正常下载，唯独下载a01.lrc文件时出现异常。

Java code

    
    
    
    

     
     
     
      
     
     
     
     class
     
     
     
      DownloadThread 
     
     
     
     implements
     
     
     
      Runnable { 
     
     
     
     private
     
     
     
      Mp3Info mp3Info 
     
     
     
     =
     
     
     
      
     
     
     
     null
     
     
     
     ; 
     
     
     
     public
     
     
     
      DownloadThread(Mp3Info mp3Info) { 
     
     
     
     this
     
     
     
     .mp3Info 
     
     
     
     =
     
     
     
      mp3Info; } @Override 
     
     
     
     public
     
     
     
      
     
     
     
     void
     
     
     
      run() { 
     
     
     
     //
     
     
     
      下载地址http:
     
     
     
     //
     
     
     
     192.168.1.102/testWeb/歌曲名 
     
     
     
     //
     
     
     
      根据MP3文件的名字，生成下载地址 
     
     
     
     //
     
     
     
     String mp3Name = mp3Info.getMp3Name(); 
     
     
     
     //
     
     
     
     String mp3Name = "a04.lrc";
     
     
     
      
     
     
     
      String mp3Name
     
     
     
     =
     
     
     
     ""
     
     
     
     ; 
     
     
     
     try
     
     
     
      { mp3Name 
     
     
     
     =
     
     
     
      URLEncoder.encode(
     
     
     
     "
     
     
     
     a04.lrc
     
     
     
     "
     
     
     
     ,
     
     
     
     "
     
     
     
     UTF-8
     
     
     
     "
     
     
     
     ); } 
     
     
     
     catch
     
     
     
      (UnsupportedEncodingException e) { 
     
     
     
     //
     
     
     
      TODO Auto-generated catch block
     
     
     
      
     
     
     
      e.printStackTrace(); } String mp3Url 
     
     
     
     =
     
     
     
      mp3url_head 
     
     
     
     +
     
     
     
      URLEncoder.encode(mp3Name); 
     
     
     
     //
     
     
     
      
     
     
     
     //
     
     
     
     生成下载文件所用的对象 
     
     
     
     //
     
     
     
      HttpDownloader httpDownloader = new HttpDownloader(); 
     
     
     
     //
     
     
     
      将文件下载下来，并存储到SDCard中
     
     
     
      
     
     
     
      
     
     
     
     int
     
     
     
      result 
     
     
     
     =
     
     
     
      httpDownloader.downFile(mp3Url, mp3Path, URLEncoder.encode(mp3Name)); String resultMessage 
     
     
     
     =
     
     
     
      
     
     
     
     null
     
     
     
     ; 
     
     
     
     if
     
     
     
      (result 
     
     
     
     ==
     
     
     
      
     
     
     
     -
     
     
     
     1
     
     
     
     ) { resultMessage 
     
     
     
     =
     
     
     
      mp3Name 
     
     
     
     +
     
     
     
      
     
     
     
     "
     
     
     
     下载失败
     
     
     
     "
     
     
     
     ; cancelled 
     
     
     
     =
     
     
     
      
     
     
     
     true
     
     
     
     ; } 
     
     
     
     else
     
     
     
      
     
     
     
     if
     
     
     
      (result 
     
     
     
     ==
     
     
     
      
     
     
     
     1
     
     
     
     ) { resultMessage 
     
     
     
     =
     
     
     
      mp3Name 
     
     
     
     +
     
     
     
      
     
     
     
     "
     
     
     
     已存在，无需重复下载
     
     
     
     "
     
     
     
     ; cancelled 
     
     
     
     =
     
     
     
      
     
     
     
     true
     
     
     
     ; } 
     
     
     
     else
     
     
     
      
     
     
     
     if
     
     
     
      (result 
     
     
     
     ==
     
     
     
      
     
     
     
     0
     
     
     
     ) { resultMessage 
     
     
     
     =
     
     
     
      mp3Name 
     
     
     
     +
     
     
     
      
     
     
     
     "
     
     
     
     下载成功
     
     
     
     "
     
     
     
     ; } 
     
     
     
     //
     
     
     
      发送特定action的广播
     
     
     
      
     
     
     
      Intent Broadcastintent 
     
     
     
     =
     
     
     
      
     
     
     
     new
     
     
     
      Intent(); Broadcastintent.setAction(
     
     
     
     "
     
     
     
     android.intent.action.MY_RECEIVER
     
     
     
     "
     
     
     
     ); Broadcastintent.putExtra(
     
     
     
     "
     
     
     
     resultMessage
     
     
     
     "
     
     
     
     , resultMessage); sendBroadcast(Broadcastintent); } } 
    
    
    
    

 httpDownloader.downFile代码

Java code

    
    
    
    

     
     
     
      
     
     
     
     /**
     
     
     
      * 该函数返回整形 -1：代表下载文件出错 0：代表下载文件成功 1：代表文件已经存在 
     
     
     
     */
     
     
     
      
     
     
     
     public
     
     
     
      
     
     
     
     int
     
     
     
      downFile(String urlStr, String path, String fileName) { InputStream inputStream 
     
     
     
     =
     
     
     
      
     
     
     
     null
     
     
     
     ; 
     
     
     
     try
     
     
     
      { 
     
     
     
     if
     
     
     
      (fileUtils.isFileExist(fileName, path)) { 
     
     
     
     return
     
     
     
      
     
     
     
     1
     
     
     
     ; } 
     
     
     
     else
     
     
     
      { inputStream 
     
     
     
     =
     
     
     
      getInputStreamFromUrl(urlStr); File resultFile 
     
     
     
     =
     
     
     
      fileUtils.write2SDFromInput(path, fileName, inputStream); 
     
     
     
     if
     
     
     
      (resultFile 
     
     
     
     ==
     
     
     
      
     
     
     
     null
     
     
     
     ) { 
     
     
     
     return
     
     
     
      
     
     
     
     -
     
     
     
     1
     
     
     
     ; } } } 
     
     
     
     catch
     
     
     
      (Exception e) { e.printStackTrace(); 
     
     
     
     return
     
     
     
      
     
     
     
     -
     
     
     
     1
     
     
     
     ; } 
     
     
     
     finally
     
     
     
      { 
     
     
     
     try
     
     
     
      { inputStream.close(); } 
     
     
     
     catch
     
     
     
      (Exception e) { e.printStackTrace(); } } 
     
     
     
     return
     
     
     
      
     
     
     
     0
     
     
     
     ; } 
    
    
    
    

getInputStreamFromUrl代码

Java code

    
    
    
    

     
     
     
      
     
     
     
     public
     
     
     
      InputStream getInputStreamFromUrl(String urlStr) 
     
     
     
     throws
     
     
     
      MalformedURLException, IOException { url 
     
     
     
     =
     
     
     
      
     
     
     
     new
     
     
     
      URL(urlStr); HttpURLConnection urlConn 
     
     
     
     =
     
     
     
      (HttpURLConnection) url.openConnection(); urlConn.setRequestMethod(
     
     
     
     "
     
     
     
     GET
     
     
     
     "
     
     
     
     ); InputStream inputStream 
     
     
     
     =
     
     
     
      urlConn.getInputStream(); 
     
     
     
     this
     
     
     
     .lenghtOfFile 
     
     
     
     =
     
     
     
      urlConn.getContentLength(); 
     
     
     
     return
     
     
     
      inputStream; } 
    
    
    
    

fileUtils.write2SDFromInput代码

Java code

    
    
    
    

     
     
     
      
     
     
     
     /**
     
     
     
      * 将一个InputStream里面的数据写入到SD卡中 
     
     
     
     */
     
     
     
      
     
     
     
     public
     
     
     
      File write2SDFromInput(String path, String fileName, InputStream input) { File file 
     
     
     
     =
     
     
     
      
     
     
     
     null
     
     
     
     ; OutputStream output 
     
     
     
     =
     
     
     
      
     
     
     
     null
     
     
     
     ; 
     
     
     
     try
     
     
     
      { creatSDDir(path); file 
     
     
     
     =
     
     
     
      createFileInSDCard(fileName, path); output 
     
     
     
     =
     
     
     
      
     
     
     
     new
     
     
     
      FileOutputStream(file); 
     
     
     
     byte
     
     
     
      buffer[] 
     
     
     
     =
     
     
     
      
     
     
     
     new
     
     
     
      
     
     
     
     byte
     
     
     
     [
     
     
     
     4
     
     
     
      
     
     
     
     *
     
     
     
      
     
     
     
     1024
     
     
     
     ]; 
     
     
     
     int
     
     
     
      temp; 
     
     
     
     while
     
     
     
      ((temp 
     
     
     
     =
     
     
     
      input.read(buffer)) 
     
     
     
     !=
     
     
     
      
     
     
     
     -
     
     
     
     1
     
     
     
     ) { 
     
     
     
     this
     
     
     
     .total 
     
     
     
     +=
     
     
     
      temp;
     
     
     
     //
     
     
     
      total = total + temp
     
     
     
      
     
     
     
      output.write(buffer, 
     
     
     
     0
     
     
     
     , temp); } output.flush(); } 
     
     
     
     catch
     
     
     
      (Exception e) { e.printStackTrace(); } 
     
     
     
     finally
     
     
     
      { 
     
     
     
     try
     
     
     
      { output.close(); } 
     
     
     
     catch
     
     
     
      (Exception e) { e.printStackTrace(); } } 
     
     
     
     return
     
     
     
      file; } 
    
    
    
    

异常情况：

08-01 09:24:37.934: W/System.err(7773): java.io.FileNotFoundException: http://192.168.1.100/testWeb/a04.lrc
08-01 09:24:37.934: W/System.err(7773): at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:1162)
08-01 09:24:37.944: W/System.err(7773): at hk.download.HttpDownloader.getInputStreamFromUrl(HttpDownloader.java:108)
08-01 09:24:37.944: W/System.err(7773): at hk.download.HttpDownloader.downFile(HttpDownloader.java:75)
08-01 09:24:37.954: W/System.err(7773): at hk.mp3player.service.DownloadService$DownloadThread.run(DownloadService.java:175)
08-01 09:24:37.954: W/System.err(7773): at java.lang.Thread.run(Thread.java:1096)
08-01 09:24:37.954: W/System.err(7773): java.lang.NullPointerException
08-01 09:24:37.954: W/System.err(7773): at hk.download.HttpDownloader.downFile(HttpDownloader.java:87)
08-01 09:24:37.954: W/System.err(7773): at hk.mp3player.service.DownloadService$DownloadThread.run(DownloadService.java:175)
08-01 09:24:37.964: W/System.err(7773): at java.lang.Thread.run(Thread.java:1096)
08-01 09:24:38.004: W/System.err(7773): java.io.FileNotFoundException: http://192.168.1.100/testWeb/a03.lrc
08-01 09:24:38.004: W/System.err(7773): at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:1162)
08-01 09:24:38.014: W/System.err(7773): at hk.download.HttpDownloader.getInputStreamFromUrl(HttpDownloader.java:108)
08-01 09:24:38.014: W/System.err(7773): at hk.download.HttpDownloader.downFile(HttpDownloader.java:75)
08-01 09:24:38.014: W/System.err(7773): at hk.mp3player.service.DownloadService$DownloadlrcThread.run(DownloadService.java:215)
08-01 09:24:38.014: W/System.err(7773): at java.lang.Thread.run(Thread.java:1096)
08-01 09:24:38.014: W/System.err(7773): java.lang.NullPointerException
08-01 09:24:38.064: W/System.err(7773): at hk.download.HttpDownloader.downFile(HttpDownloader.java:87)
08-01 09:24:38.064: W/System.err(7773): at hk.mp3player.service.DownloadService$DownloadlrcThread.run(DownloadService.java:215)
08-01 09:24:38.064: W/System.err(7773): at java.lang.Thread.run(Thread.java:1096)

解决方法！！

Win7 在IIS中增加MIME类型文件，步骤如下：

第一步：开始 ->  所有程序 -> 管理工具 -> Internet 信息服务(IIS)管理器

第二步：点击“MIME”类型：

第三步：在上图右侧有一个“添加”按钮，如下图：

第四步：填写MIME设置，例如添加.lrc文件，如下图：