I have question regarding best practices.

Let's say I am writing a method that takes a String parameter and
returns a formatted String.

For this discussion we'll use the following.

String makeUpper( String paramString ) {
   return parameterString.toUpperCase();
}

If parameterString is null then the code will return a
NullPointerException.  I have two ways to solve this problem.

Use a try/catch block
String makeUpper( String paramString ) {
   try {
       return parameterString.toUpperCase();
   }
   catch ( NullPointerException e ) {
       return "-";
   }
}

OR

Use an if/else condition
String makeUpper( String paramString ) {
   if ( paramString != null ) {
       return parameterString.toUpperCase();
   }
   else {
       return "-";
   }
}

As far as I know both will accomplish the same thing, but I am not sure
which is the best practice for such situations or if it just personal
preference.

If one is better than the other, please set me straight.

Thanks