下面是DiskBasedCache#pruneIfNeeded()源码：
private void pruneIfNeeded(int neededSpace) {
if ((mTotalSize + neededSpace) < mMaxCacheSizeInBytes) {
return;
}
long before = mTotalSize;
int prunedFiles = 0;
long startTime = SystemClock.elapsedRealtime();
Iterator<map.entry<string, cacheheader="">> iterator = mEntries.entrySet().iterator();
while (iterator.hasNext()) {
Map.Entry<string, cacheheader=""> entry = iterator.next();
CacheHeader e = entry.getValue();
boolean deleted = getFileForKey(e.key).delete();
if (deleted) {
mTotalSize -= e.size;
} else {
}
iterator.remove();
prunedFiles++;
&nbs
