Conditional operator with Guava's Optional object in Java 7

Question

I want to use the conditional operator in Java 7 where the returned object is com.google.common.base.Optional , something like this:

import com.google.common.base.Optional;
public Optional<String> getFirstElement(String str, String separator) {
    final String[] strs = str.split(separator);
    return strs.length == 0 ? Optional.absent() : Optional.of(strs[0]);
}

However, Optional.absent() has type Optional<?> instead of Optional<String> . Any idea about how to solve this?

Answer 1

On Java 7, just specify the type explicitly

public Optional<String> getFirstElement(String str, String separator) {
    final String[] strs = str.split(separator);
    return strs.length == 0 ? Optional.<String>absent() : Optional.of(strs[0]);
}

The Optional#absent() method is generic.

In Java 8, your code will compile fine thanks to some improved type inferrence.