praveenhm · February 22, 2016 19:59 · Feb 22, 2016
diff --git a/TypeReference.java b/TypeReference.java
@@ -0,0 +1,43 @@
+
+public abstract class TypeReference<T> {
+
+    private final Type type;
+    private volatile Constructor<?> constructor;
+
+    protected TypeReference() {
+        Type superclass = getClass().getGenericSuperclass();
+        if (superclass instanceof Class) {
+            throw new RuntimeException("Missing type parameter.");
+        }
+        this.type = ((ParameterizedType) superclass).getActualTypeArguments()[0];
+    }
+
+    /**
+     * Instantiates a new instance of {@code T} using the default, no-arg
+     * constructor.
+     */
+    @SuppressWarnings("unchecked")
+    public T newInstance()
+            throws NoSuchMethodException, IllegalAccessException,
+                   InvocationTargetException, InstantiationException {
+        if (constructor == null) {
+            Class<?> rawType = type instanceof Class<?>
+                ? (Class<?>) type
+                : (Class<?>) ((ParameterizedType) type).getRawType();
+            constructor = rawType.getConstructor();
+        }
+        return (T) constructor.newInstance();
+    }
+
+    /**
+     * Gets the referenced type.
+     */
+    public Type getType() {
+        return this.type;
+    }
+
+    public static void main(String[] args) throws Exception {
+        List<String> l1 = new TypeReference<ArrayList<String>>() {}.newInstance();
+        List l2 = new TypeReference<ArrayList>() {}.newInstance();
+    }
+}