This post is older than a year. Consider some information might not be accurate anymore.
Since I have a bunch of generated html filed from my WordPress migration to Jekyll, I needed to replace some values in all generated files. IntelliJ has powerful search and replace capabilities.
First select the value you need to replace and enter the substitution in the assistant. Choose the base path, for the replacements.
After you executed the search, IntelliJ requests the scope of the action. Replace all files are perfect.
For more options take a look at the IntelliJ Help.