http://www.dropwizard.io/1.3.16/dropwizard-jersey: Dropwizard is a Java framework for developing ops-friendly, high-performance, RESTful web applications.
  • Coda Hale
  • Nick Telford
  • Graham O'Regan
  • Ryan Kennedy
  • Camille Fournier
  • Carlo Barbara
  • Matt Veitas
  • Ryan Tenney
  • Jochen Schalanda
  • Glenn McAllister
  • Nick Babcock
  • Justin Plock
  • Artem Prigoda 
package io.dropwizard.jersey.params;

import com.google.common.base.Strings;

import javax.annotation.Nullable;
import java.util.Optional;


A parameter encapsulating optional string values with the condition that empty string inputs are interpreted as being absent. This class is useful when it is desired for empty parameters to be synonymous with absent parameters instead of empty parameters evaluating to Optional.of(""). 
/**
 * A parameter encapsulating optional string values with the condition that empty string inputs are
 * interpreted as being absent. This class is useful when it is desired for empty parameters to be
 * synonymous with absent parameters instead of empty parameters evaluating to
 * {@code Optional.of("")}.
 */
public class NonEmptyStringParam extends AbstractParam<Optional<String>> {
    public NonEmptyStringParam(@Nullable String input) {
        super(input);
    }

    public NonEmptyStringParam(@Nullable String input, String parameterName) {
        super(input, parameterName);
    }

    @Override
    protected Optional<String> parse(@Nullable String input) throws Exception {
        return Optional.ofNullable(Strings.emptyToNull(input));
    }
}