统计目录大小和时间删除早期的大文件

为什么要做这些，等你需要的时候你就知道了

private void deleteOldestFile(File directory)
{
File[] files = directory.listFiles();
Arrays.sort(files, new Comparator<File>() { 
    @Override
    public int compare(File f1, File f2) 
    {       
        return Long.valueOf(f1.lastModified()).compareTo(f2.lastModified());        
    }});
files[0].delete();
 }
private static long dirSize(File dir) {
long result = 0;
File[] fileList = dir.listFiles();
for(int i = 0; i < fileList.length; i++) {
    if(fileList[i].isDirectory()) {
        result += dirSize(fileList [i]);
    } else {
        // Sum the file size in bytes
        result += fileList[i].length();
    }
 }
return result; 
}

File dirlist = new File(Environment.getExternalStorageDirectory() + "/VideoList");
if(!(dirlist.exists()))
dirlist.mkdir();
Long directorySize = dirSize(dirlist);
 if (directorySize > 1073741824) // this is 1GB in bytes
 {
    deleteOldestFile(dirlist); 
 }
File TempFile = new File(Environment.getExternalStorageDirectory() 
                + "/VideoList", dateFormat.format(date) + fileFormat);
mediaRecorder.setOutputFile(TempFile.getPath());

或者

while (directorySize > 1073741824)
{
  deleteOldestFile(dirlist);
  direcotrySize = dirSize(dirlist);
}