Here Keywords are extracted from pdf file if we are aware of list of possible keywords for the given document or domain.
The result contains three column namely 'Keywords' which list out all present keywords in pdf file, 'Normalized Weightage' which is used to know the importance of keywords in that document. This importance is calculated by counting number of occurrence of all keywords in that document. Thus weightage is calculated from only one document and 'No of occurrence' is the number of occurrence of keywords in that document.
The pdf file is of Basic java notes. Since this file is related to java programming language. Hence java programming language related keywords are used for extraction.