public BlobKey getBlobKey(AppEngineFile file) {
if (null == file) {
throw new NullPointerException("file is null");
}
if (file.getFileSystem() != AppEngineFile.FileSystem.BLOBSTORE) {
throw new IllegalArgumentException("file is not of type BLOBSTORE");
}
BlobKey cached = getCachedBlobKey(file);
if (null != cached) {
return cached;
}
String creationHandle = getCreationHandle(file);
if (creationHandle == null) {
return new BlobKey(file.getNamePart());
}
Entity blobInfoEntity = getBlobInfoEntity(creationHandle);
if (blobInfoEntity == null) {
return null;
}
BlobInfo blobInfo = new BlobInfoFactory().createBlobInfo(blobInfoEntity);
return blobInfo.getBlobKey();
}
