IntelliJ IDEA “cannot resolve symbol” and “cannot resolve method”

Question

What are common causes for IntelliJ IDEA not being able to resolve built-in JVM types and methods? For example, when I mouse over String the tooltip says \"Cann

Answer 1

I was facing the same problem when import projects into IntelliJ.

for in my case first, check SDK details and check you have configured JDK correctly or not.

Go to File-> Project Structure-> platform Settings-> SDKs

Check your JDK is correct or not.

Next, I Removed project from IntelliJ and delete all IntelliJ and IDE related files and folder from the project folder (.idea, .settings, .classpath, dependency-reduced-pom). Also, delete the target folder and re-import the project.

The above solution worked in my case.