FileNotFoundException: Thrown when an attempt to open the file denoted by a specified pathname has failed.
Example:

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
try {
 File file = new File("nonexistentFile.txt");
 FileReader fr = new FileReader(file);
} catch (FileNotFoundException e) {
 System.out.println("Caught FileNotFoundException: " + e.getMessage());
}