Little utility class to easily label any Java enum into a value in a message file

EnumLabel.java

package fr.gist.util;

import java.lang.reflect.Method;
import java.util.ResourceBundle;

/*
 * Auto Label enums matching a label.properties message file
 * 
 * The message key has the format : <type>.<name>
 *
 * Chain:
 *    - if there is a getLabel method => call getLabel method
 *    - then if there is a match in message file => go for it
 *    - else => uppercase name of the enum
 */
public class EnumLabel {

   private final static ResourceBundle bundle = ResourceBundle.getBundle("fr.gist.util.label");

   private final static String KEY_SEPARATOR = ".";

   private final static String LABEL_METHOD = "getLabel";

   //TODO: The call chain should not be write in hard code
   public static String autoLabel(Enum toConvert) {
      return getLabel(toConvert);
   }

   private static String getLabel(Enum toConvert) {
      Method getLabel = hasGetLabelMethod(toConvert);

      if(getLabel != null) {
         try {
            return (String) getLabel.invoke(toConvert);
         } catch (Exception e) {
            return getAlternativeName(toConvert);
         }
      }

      return getAlternativeName(toConvert);
   }

   private static String getAlternativeName(Enum toConvert) {
      String searchKey = getEnumType(toConvert) + KEY_SEPARATOR + getEnumName(toConvert);

      return bundle.containsKey(searchKey) ? bundle.getString(searchKey) : getStandardName(toConvert);
   }

   // Made this Class usable with every Enumeration
   private static String getStandardName(Enum toConvert) {
      return toConvert.name();
   }

   // Message file related methods
   private static String getEnumName(Enum toConvert) {
      return getStandardName(toConvert).toLowerCase();
   }

   private static String getEnumType(Enum toConvert) {
      return toConvert.getDeclaringClass().getSimpleName().toLowerCase();
   }

   // Unit DuckTyping
   private static Method hasGetLabelMethod(Enum toConvert) {
      Method method = null;

      try {
         method = toConvert.getClass().getMethod(LABEL_METHOD);
      } catch (NoSuchMethodException e) {
         return method;
      }

      return method;
   }
}

EnumLabelTest.java

package fr.gist.util;

import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.assertThat;

import org.junit.Test;

enum BaseEnumTest {
    MESSAGE, BLANK, NO_MESSAGE
}

enum LabelEnumTest {

    LABEL("inLabel");

    String label;

    LabelEnumTest(String label) {
        this.label = label;
    }

    public String getLabel() {
        return label;
    }
}

public class EnumLabelTest {

   @Test
   public void testGetLabel() {
      // When
      String availableLabel = EnumLabel.autoLabel(BaseEnumTest.MESSAGE);

      // Then
      assertThat(availableLabel, is("message"));
   }

   @Test
   public void testGetLabelBlank() {
      // When
      String availableLabel = EnumLabel.autoLabel(BaseEnumTest.BLANK);

      // Then
      assertThat(availableLabel, is(""));
   }

   @Test
   public void testGetLabelIfNoMessage() {
      // When
      String availableLabel = EnumLabel.autoLabel(BaseEnumTest.NO_MESSAGE);

      // Then
      assertThat(availableLabel, is("NO_MESSAGE"));
   }

   @Test
   public void testGetLabelIfLabel() {
      // When
      String availableLabel = EnumLabel.autoLabel(LabelEnumTest.LABEL);

      // Then
      assertThat(availableLabel, is("inLabel"));
   }
}

label.properties

#BaseEnumTest
baseenumtest.message=message
baseenumtest.blank=