/* package whatever; // don't place package name! */
 
import java.util.*;
import java.lang.*;
import java.io.*;
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
    public static void main(String[] args) {
        System.out.println(validaPlaca("AAA3B11")); // true
        System.out.println(validaPlaca("DXQ9F92")); // true
        System.out.println(validaPlaca("ABC1233")); // false
        System.out.println(validaPlaca("1234")); // false
        System.out.println(validaPlaca("")); // false
    }
 
    public static boolean validaPlaca(String placa) {
        if (placa == null) {
            return false;
        }
 
        return placa.matches("^[A-Z]{3}[0-9][A-Z][0-9]{2}$");
    }
}

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