how to detect latest open file on computer and detect absolute file path

[jhovarie]

hello guys i have only a basic knowledge about c++ im a java user but some times i found some difficulty using java and i use to combine c++ and java to achieve my goals. and this is my problem.

im developing some text editor and one of my project is pdfreader or pdfviewer and here is my problem.

how to detect latest open file on computer and detect absolute file path? i want to do this to achieve this so that i can use it on my project.

i already post this related question in https://forums.oracle.com/forums/thread.jspa?messageID=9872038#9872038
my question there is
-start-
Hello Every one i have an application a java application that read pdf file and display
the pdf file on a jPanel but i hate the way it work because before i can open and read
pdf file i must click the jmenuitem and open the jfilebrowser so that my java application will open and read the pdf file.

i want that i will automatically click any pdf file on my computer with out running my java application and my application will automatically run and will be the one who read the pdf file if i double click any pdf file on my computer.
-end-

plss help.. where should i start to achieve this?