Online Java Regular Expression Testing

Here is an online regular expression testing for Java. For example, to find all comments in a source code file.

First input //.* as regular expression, input some strings for testing, such as "//testing", "testing".

When it is submitted, the web page gives the following result.

For reference to use Regular Expression, here is a pretty good and brief guide.

Category >> Regular Expressions  
If you want someone to read your code, please put the code inside <pre><code> and </code></pre> tags. For example:
String foo = "bar";