android 异常，求各位大神帮帮忙！！

aaa225213 2013-05-08 10:28:44

05-08 14:21:14.318: DEBUG/dalvikvm(133): GC_EXPLICIT freed 782 objects / 43792 bytes in 250ms
05-08 14:21:15.128: WARN/System.err(1368): java.io.IOException: Permission denied
05-08 14:21:15.128: WARN/System.err(1368): at java.io.File.createNewFileImpl(Native Method)
05-08 14:21:15.149: WARN/System.err(1368): at java.io.File.createNewFile(File.java:1160)
05-08 14:21:15.149: WARN/System.err(1368): at com.utils.FileUtils.createFileInSDCard(FileUtils.java:26)
05-08 14:21:15.149: WARN/System.err(1368): at com.utils.FileUtils.write2SDFromInput(FileUtils.java:58)
05-08 14:21:15.149: WARN/System.err(1368): at com.download.HttpDownloader.downFile(HttpDownloader.java:66)
05-08 14:21:15.178: WARN/System.err(1368): at com.mp3player.service.DownloadService$DownloadThread.run(DownloadService.java:44)
05-08 14:21:15.178: WARN/System.err(1368): at java.lang.Thread.run(Thread.java:1096)
05-08 14:21:15.178: WARN/System.err(1368): java.lang.NullPointerException
05-08 14:21:15.178: WARN/System.err(1368): at com.utils.FileUtils.write2SDFromInput(FileUtils.java:72)
05-08 14:21:15.178: WARN/System.err(1368): at com.download.HttpDownloader.downFile(HttpDownloader.java:66)
05-08 14:21:15.178: WARN/System.err(1368): at com.mp3player.service.DownloadService$DownloadThread.run(DownloadService.java:44)
05-08 14:21:15.178: WARN/System.err(1368): at java.lang.Thread.run(Thread.java:1096)
05-08 14:21:19.558: DEBUG/dalvikvm(200): GC_EXPLICIT freed 93 objects / 3776 bytes in 419ms
05-08 14:21:24.387: DEBUG/dalvikvm(256): GC_EXPLICIT freed 53 objects / 2512 bytes in 250ms
05-08 14:22:09.768: DEBUG/SntpClient(58): request time failed: java.net.SocketException: Address family not supported by protocol

权限已经有了，如下：
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
</manifest>
FileUtils()函数如下：
public FileUtils() {
//得到当前外部存储设备的目录
SDCardRoot = Environment.getExternalStorageDirectory().getAbsolutePath() + File.separator;
}
public File createFileInSDCard(String fileName,String dir) throws IOException {
File file = new File(SDCardRoot+ dir + File.separator + fileName);
System.out.println("file--->" + file);
file.createNewFile();
return file;
}
public File creatSDDir(String dir) {
File dirFile = new File(SDCardRoot + dir + File.separator);
System.out.println(dirFile.mkdirs());
return dirFile;
}
public boolean isFileExist(String fileName,String path){
File file = new File(SDCardRoot + path + File.separator + fileName);
return file.exists();
}

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