Ejemplo

public class ClassA {

public ClassA () {
}

public void methodA () {
//..
}
public static void main (String [] args) {
//..
}
public void methodB () {
//..
}
}

Solución
Coloque el método main(String [] args) al final de la clase.

public class ClassA {

public ClassA () {
}

public void methodA () {
//..
}
public void methodB() {
//..
}
public static void main (String [] args) {
//..
}
}