[java] How to check if a folder exists

From SonarLint, if you already have the path, use path.toFile().exists() instead of Files.exists for better performance.

The Files.exists method has noticeably poor performance in JDK 8, and can slow an application significantly when used to check files that don't actually exist.

The same goes for Files.notExists, Files.isDirectory and Files.isRegularFile.

Noncompliant Code Example:

Path myPath;
if(java.nio.Files.exists(myPath)) {  // Noncompliant
    // do something
}

Compliant Solution:

Path myPath;
if(myPath.toFile().exists())) {
    // do something
}