Code inspections
In IntelliJ IDEA, there is a set of code inspections that detect and correct anomalous code in your project before you compile it. The IDE can find and highlight various problems, locate dead code, find probable bugs, spelling problems, and improve the overall code structure.
Inspections can scan your code in all project files, or only in specific scopes (for example, only in production code, or in modified files).
Every inspection has a severity level — the extent to which a problem can affect your code. Severities are highlighted differently in the editor so that you can quickly distinguish between critical problems and less important things. IntelliJ IDEA comes with a set of predefined severity levels and enables you to create your own.
Inspections and their settings are grouped in profiles. Each profile contains the information on the enabled inspections, a scope of files that they analyze, and their severity levels.
Access all available inspections and their settings
In the Settings/Preferences dialog Ctrl+Alt+S, go to .
You can also press Ctrl+Alt+Shift+H and select Configure Inspections in the popup that opens.
Use 
to filter the inspections list. For example, you can filter inspections by severity or by language.