question: public void testPurge ( ) throws Exception { List < MemoryFile > files = new ArrayList < MemoryFile > ( ) ; try { while ( true ) { MemoryFile newFile = new MemoryFile ( "MemoryFileTest" , 10000000 ) ; newFile . allowPurging ( true ) ; newFile . writeBytes ( testString , 0 , 0 , testString . length ) ; files . add ( newFile ) ; for ( MemoryFile file : files ) { try { file . readBytes ( testString , 0 , 0 , testString . length ) ; } catch ( IOException e ) { return ; } } } } finally { for ( MemoryFile fileToClose : files ) { fileToClose . close ( ) ; } } }
target:  Keep allocating new files till the system purges them.