Take a look at the String.compareTo method.

Copys1.compareTo(s2)

From the javadocs:

The result is a negative integer if this String object lexicographically precedes the argument string. The result is a positive integer if this String object lexicographically follows the argument string. The result is zero if the strings are equal; compareTo returns 0 exactly when the equals(Object) method would return true.

Copyint compare = a.compareTo(b);
if (compare < 0){
    System.out.println(a + " is before " +b);
} else if (compare > 0) {
    System.out.println(b + " is before " +a);
} else {
    System.out.println("Strings are equal")
}

If you would like to ignore case you could use the following:

String s = "yip";
String best = "yodel";
int compare = s.compareToIgnoreCase(best);
if(compare < 0){
    //-1, --> s is less than best. ( s comes alphabetically first)
}
else if(compare > 0 ){
// best comes alphabetically first.
}
else{
    // strings are equal.
}