Question

The following code doesn’t compile

import com.google.common.collect.LinkedHashMultimap;

public class Test {
    public static void main(String[] args) {
        LinkedHashMultimap<String, String> p = new LinkedHashMultimap<String, String>();    
    }
}

the error is: The constructor LinkedHashMultimap() is not visible

I have imported the google Java libraries, they are in the build path

and

        LinkedHashMultimap<String, String> p;

alone doesn’t cause compile error… weird

Answer 1

LinkedHashMultimap has no public constructors and the way to get an instance is by using the factory method create. The reason for this is the loophole in Java Generics due to which type inference works only for methods and not for constructors. This means that instead of for example

LinkedHashMultimap<String, Map<String, List<String>>> = 
  new LinkedHashMultimap<String, Map<String, List<String>>>();

you can write

LinkedHashMultimap<String, Map<String, List<String>>> = 
  LinkedHashMultimap.create();

With Java 7 the pressure has subsided due to the “diamond operator”.