private int removeNext(){
  if (lastUsageDates.isEmpty()) {
    return INVALID_SIZE;
  }
  Long oldestUsage=null;
  File mostLongUsedFile=null;
  Set<Entry<File,Long>> entries=lastUsageDates.entrySet();
synchronized (lastUsageDates) {
    for (    Entry<File,Long> entry : entries) {
      if (mostLongUsedFile == null) {
        mostLongUsedFile=entry.getKey();
        oldestUsage=entry.getValue();
      }
 else {
        Long lastValueUsage=entry.getValue();
        if (lastValueUsage < oldestUsage) {
          oldestUsage=lastValueUsage;
          mostLongUsedFile=entry.getKey();
        }
      }
    }
  }
  int fileSize=0;
  if (mostLongUsedFile != null) {
    if (mostLongUsedFile.exists()) {
      fileSize=getSize(mostLongUsedFile);
      if (mostLongUsedFile.delete()) {
        lastUsageDates.remove(mostLongUsedFile);
      }
    }
 else {
      lastUsageDates.remove(mostLongUsedFile);
    }
  }
  return fileSize;
}

private int removeNext ( ) { if ( lastUsageDates . isEmpty ( ) ) { return INVALID_SIZE ; } Long oldestUsage = null ; File mostLongUsedFile = null ; Set < Entry < File , Long > > entries = lastUsageDates . entrySet ( ) ; synchronized ( lastUsageDates ) { for ( Entry < File , Long > entry : entries ) { if ( mostLongUsedFile == null ) { mostLongUsedFile = entry . getKey ( ) ; oldestUsage = entry . getValue ( ) ; } else { Long lastValueUsage = entry . getValue ( ) ; if ( lastValueUsage < oldestUsage ) { oldestUsage = lastValueUsage ; mostLongUsedFile = entry . getKey ( ) ; } } } } int fileSize = 0 ; if ( mostLongUsedFile != null ) { if ( mostLongUsedFile . exists ( ) ) { fileSize = getSize ( mostLongUsedFile ) ; if ( mostLongUsedFile . delete ( ) ) { lastUsageDates . remove ( mostLongUsedFile ) ; } } else { lastUsageDates . remove ( mostLongUsedFile ) ; } } return fileSize ; }
remove next file and returns it ' s size
