"In a Java method": do you by any chance mean programming language by the word method? If so, you should say in the Java programming language, or, preferably, just in Java, just like we say: programs written in C++, Visual Basic etc. If method is what you mean, though, then it's ok, since, as I infer from you new post, you're actually saying there are more than one methods.
"I am here with attaching HLD document for review": I'm not sure I quite understand what you mean. Are you saying you're still at your computer attaching some document you're about to send by email perhaps? If that is the case, then something along the following lines should do: "I'm still here, just about to send an email with an attached HLD document for review".