What are these weird symbols showing up in my source code listings?

Question

I have a LaTeX document, and am trying to embed some Java code via the listings package. I have the following LaTeX source:

\documentclass{article}
\usepackage{listings}
\title{Sample Document}
\begin{document}

\section*{Source Code:}

\lstset{ language=Java }
\lstinputlisting{example.java}

\end{document}

And, for the most part, the code shows up nicely. But, in certain places I get these weird symbols where spaces should be (code coloring added):

It appears that, within any quoted string, the spaces are converted to these U-like symbols. Any idea why this is happening?

Answer 1

Spaces in strings appear as the symbol you mentioned. To suppress the symbols showing the spaces, add the option showstringspaces=false to \lstset.