Lots of code cleanup, including removing some useless null checks,

preventing some NPE's before they ever occur, and clean up some
of the inheritance hierarchy.

forge-core/src/main/java/forge/util/ReflectionUtil.java

@@ -1,40 +1,61 @@
 package forge.util;
 
 import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
 
-/** 
- * TODO: Write javadoc for this type.
- *
+/**
+ * Static utilities related to reflection.
+ * 
+ * @see java.lang.Class
  */
-public class ReflectionUtil {
+public final class ReflectionUtil {
 
-    public static <T> T makeDefaultInstanceOf(Class<? extends T> cls) {
-        if ( null == cls )
+    /**
+     * Private constructor to prevent instantiation.
+     */
+    private ReflectionUtil() {
+    }
+
+    /**
+     * Generates a default instance of the supplied class, using that class'
+     * default constructor.
+     * 
+     * @param cls
+     *            a {@link Class}.
+     * @return an instance of the supplied class.
+     * @throws RuntimeException
+     *             if the supplied class has no visible default constructor, or
+     *             if an exception is thrown by the constructor.
+     * @see Class#newInstance()
+     */
+    public static <T> T makeDefaultInstanceOf(final Class<? extends T> cls) {
+        if (null == cls) {
             throw new IllegalArgumentException("Class<? extends T> cls must not be null");
-        
-        @SuppressWarnings("unchecked")
-        Constructor<? extends T>[] cc = (Constructor<? extends T>[]) cls.getConstructors();
-        for (Constructor<? extends T> c : cc) {
-            Class<?>[] pp = c.getParameterTypes();
-            if (pp.length == 0) {
-                try {
-                    T res = c.newInstance();
-                    return res;
-                } catch (Exception e) {
-                    e.printStackTrace();
-                }
-            }
         }
-        throw new RuntimeException("No default constructor found in class " + cls.getName());
+
+        try {
+            final Constructor<? extends T> c = cls.getConstructor();
+            return c.newInstance();
+        } catch (final NoSuchMethodException e) {
+            throw new RuntimeException(String.format("No default constructor found in class %s", cls.getName()));
+        } catch (final SecurityException | InstantiationException | IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
+            throw new RuntimeException(String.format("Can't instantiate class %s using default constructor", cls.getName()));
+        }
     }
 
     /**
      * Cast object to a given type if possible, returning null if not possible
+     * 
      * @param obj
+     *            an object.
      * @param type
+     *            the {@link Class} to which to cast the object.
+     * @return a reference to the object if it's an instance of the given class,
+     *         or {@code null} if it isn't.
+     * @see Class#isInstance(Object)
      */
     @SuppressWarnings("unchecked")
-    public static <T> T safeCast(Object obj, Class<T> type) {
+    public static <T> T safeCast(final Object obj, final Class<T> type) {
         if (type.isInstance(obj)) {
             return (T) obj;
         }