question: public boolean isExpired ( RepositoryProxyCache proxyCache ) { long methodCacheTime = proxyCache . getCacheTime ( ) ; boolean unlimitedCache = methodCacheTime <= 0 ; File cacheFile = buildFile ( proxyCache . getCacheDir ( ) , proxyCache . getFileName ( ) , DEFAULT_FILE_NAME ) ; if ( isCached ( cacheFile ) ) { if ( unlimitedCache ) { return false ; } long lastModifiedTime = fileManager . getLastModifiedTime ( cacheFile ) ; boolean expired = System . currentTimeMillis ( ) > ( lastModifiedTime + methodCacheTime ) ; if ( expired ) { evict ( proxyCache ) ; } return expired ; } return true ; }
target:  Warning: This is an I/O operation and this method must to be performed in a different Thread.