How can I check for an inputted word against a list of words in a text file?

I want to be able to see if an inputted string matches a line of text in a text file containing 200k+ words (1 per line).

I already looked into HashSets/HashTables, but I'm working in Java, and don't want to have to rewrite hundreds of lines of code to convert to C#. I also saw StreamReader, but that also seems more geared towards C#, and what little I did find on it with Java confused me on its own. I could do an Array, but making an array of 200k+ words would be stupidly time consuming and incredibly resource intensive.

Can anyone help me with this issue? This is literally the only thing left I need to figure out for this project, and I'd be bummed if I couldn't make it work simply because I used the wrong language the whole time.

Thanks for any input!