Add Labeled interface (#66)

src/main/java/info/freelibrary/util/Constants.java

@@ -6,125 +6,86 @@
  */
 public final class Constants {
 
-    /**
-     * A constant for a message slot.
-     */
+    /** A constant for a message slot. */
     public static final String MESSAGE_SLOT = "{}";
 
-    /**
-     * The default / any host IP address.
-     */
+    /** The default / any host IP address. */
     public static final String INADDR_ANY = "0.0.0.0"; // NOPMD - don't hard code IPs
 
-    /**
-     * A constant for an end of line character.
-     */
+    /** A constant for an end of line character. */
     public static final String EOL = System.lineSeparator();
 
-    /**
-     * A constant for an empty string.
-     */
+    /** A constant for an empty string. */
     public static final String EMPTY = "";
 
-    /**
-     * A constant for a space character.
-     */
+    /** A constant for a space character. */
     public static final String SPACE = " ";
 
-    /**
-     * A constant for a colon.
-     */
+    /** A constant for a colon. */
     public static final String COLON = ":";
 
-    /**
-     * A constant for a slash.
-     */
+    /** A constant for a slash. */
     public static final String SLASH = "/";
 
-    /**
-     * A constant for a hash.
-     */
+    /** A constant for a hash. */
     public static final String HASH = "#";
 
-    /**
-     * A constant for a dash.
-     */
+    /** A constant for a dash. */
     public static final String DASH = "-";
 
-    /**
-     * A constant for a comma.
-     */
+    /** A constant for a comma. */
     public static final String COMMA = ",";
 
-    /**
-     * A constant for a period.
-     */
+    /** A constant for a period. */
     public static final String PERIOD = ".";
 
-    /**
-     * A constant for a vertical bar.
-     */
+    /** A constant for a vertical bar. */
     public static final String VERTICAL_BAR = "|";
 
-    /**
-     * A constant for the plus symbol.
-     */
+    /** A constant for the plus symbol. */
     public static final String PLUS = "+";
 
-    /**
-     * A constant for the equals sign.
-     */
+    /** A constant for the equals sign. */
     public static final String EQUALS = "=";
 
-    /**
-     * A constant for a question mark.
-     */
+    /** A constant for a question mark. */
     public static final String QUESTION_MARK = "?";
 
-    /**
-     * A constant for a single instance.
-     */
+    /** A constant for a quote. */
+    public static final String QUOTE = "\"";
+
+    /** A constant for a single instance. */
     public static final int SINGLE_INSTANCE = 1;
 
-    /**
-     * A constant for a zero character.
-     */
+    /** A constant for a zero character. */
     public static final char ZERO_CHAR = '0';
 
-    /**
-     * A constant for a dash character.
-     */
+    /** A constant for a dash character. */
     public static final char DASH_CHAR = '-';
 
-    /**
-     * A constant for a plus character.
-     */
+    /** A constant for a plus character. */
     public static final char PLUS_CHAR = '+';
 
-    /**
-     * A constant for a dot character.
-     */
+    /** A constant for a dot character. */
     public static final char DOT_CHAR = '.';
 
-    /**
-     * A constant for the string representation of Boolean.TRUE.
-     */
+    /** A constant for the string representation of Boolean.TRUE. */
     public static final String TRUE = "true";
 
-    /**
-     * A constant for the string representation of Boolean.FALSE.
-     */
+    /** A constant for the string representation of Boolean.FALSE. */
     public static final String FALSE = "false";
 
-    /**
-     * A constant for the string representation of null.
-     */
+    /** A constant for the string representation of null. */
     public static final String NULL = "null";
 
+    /** A constant for an underscore string. */
+    public static final String UNDERSCORE = "_";
+
     /**
      * Private constructor for a constants class.
      */
     private Constants() {
+        // This is intentionally left empty.
     }
 
 }

src/main/java/info/freelibrary/util/Labeled.java

@@ -0,0 +1,15 @@
+
+package info.freelibrary.util;
+
+/**
+ * An interface for enumerations that standardizes accessing the enum's label.
+ */
+public interface Labeled {
+
+    /**
+     * Gets the enumeration's label.
+     *
+     * @return A label
+     */
+    String label();
+}