Refactor: extract static values to Constants class, split packages

Change-Id: I5d9f07b6e0d82b40d9c1fa216b233af881ff11ab
diff --git a/apps/simplefabric/app/src/main/java/org/onosproject/simplefabric/util/RouteTools.java b/apps/simplefabric/app/src/main/java/org/onosproject/simplefabric/util/RouteTools.java
new file mode 100644
index 0000000..d02fed2
--- /dev/null
+++ b/apps/simplefabric/app/src/main/java/org/onosproject/simplefabric/util/RouteTools.java
@@ -0,0 +1,56 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+ *
+ * Licensed 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.
+ */
+/*
+ * local copy of onos/incubator/api/src/main/java/org/onosproject/incubator/net/routing/RouteTools.java
+ * to remove dependency on onos.incubator.routing services, since 2017-08-09.
+ */
+
+package org.onosproject.simplefabric.util;
+
+import org.onlab.packet.IpPrefix;
+
+/**
+ * Routing tools.
+ */
+public final class RouteTools {
+
+    private RouteTools() {
+    }
+
+    /**
+     * Creates a binary string representation of an IP prefix.
+     *
+     * For each string, we put a extra "0" in the front. The purpose of
+     * doing this is to store the default route inside InvertedRadixTree.
+     *
+     * @param ipPrefix the IP prefix to use
+     * @return the binary string representation
+     */
+    public static String createBinaryString(IpPrefix ipPrefix) {
+        byte[] octets = ipPrefix.address().toOctets();
+        StringBuilder result = new StringBuilder(ipPrefix.prefixLength());
+        result.append("0");
+        for (int i = 0; i < ipPrefix.prefixLength(); i++) {
+            int byteOffset = i / Byte.SIZE;
+            int bitOffset = i % Byte.SIZE;
+            int mask = 1 << (Byte.SIZE - 1 - bitOffset);
+            byte value = octets[byteOffset];
+            boolean isSet = ((value & mask) != 0);
+            result.append(isSet ? "1" : "0");
+        }
+        return result.toString();
+    }
+}