1 files changed, 74 insertions, 0 deletions
diff --git a/src/main/java/org/apache/commons/math3/geometry/euclidean/twod/Euclidean2D.java b/src/main/java/org/apache/commons/math3/geometry/euclidean/twod/Euclidean2D.java
new file mode 100644
index 0000000..af7630d
--- /dev/null
+++ b/src/main/java/org/apache/commons/math3/geometry/euclidean/twod/Euclidean2D.java
@@ -0,0 +1,74 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.commons.math3.geometry.euclidean.twod;
+
+import java.io.Serializable;
+
+import org.apache.commons.math3.geometry.Space;
+import org.apache.commons.math3.geometry.euclidean.oned.Euclidean1D;
+
+/**
+ * This class implements a two-dimensional space.
+ * @since 3.0
+ */
+public class Euclidean2D implements Serializable, Space {
+
+    /** Serializable version identifier. */
+    private static final long serialVersionUID = 4793432849757649566L;
+
+    /** Private constructor for the singleton.
+     */
+    private Euclidean2D() {
+    }
+
+    /** Get the unique instance.
+     * @return the unique instance
+     */
+    public static Euclidean2D getInstance() {
+        return LazyHolder.INSTANCE;
+    }
+
+    /** {@inheritDoc} */
+    public int getDimension() {
+        return 2;
+    }
+
+    /** {@inheritDoc} */
+    public Euclidean1D getSubSpace() {
+        return Euclidean1D.getInstance();
+    }
+
+    // CHECKSTYLE: stop HideUtilityClassConstructor
+    /** Holder for the instance.
+     * <p>We use here the Initialization On Demand Holder Idiom.</p>
+     */
+    private static class LazyHolder {
+        /** Cached field instance. */
+        private static final Euclidean2D INSTANCE = new Euclidean2D();
+    }
+    // CHECKSTYLE: resume HideUtilityClassConstructor
+
+    /** Handle deserialization of the singleton.
+     * @return the singleton instance
+     */
+    private Object readResolve() {
+        // return the singleton instance
+        return LazyHolder.INSTANCE;
+    }
+
+}