[ONOS-3833] Load balance identifier class and UT

Change-Id: Ice90fbc56be8e214ed9e6657a32eff8839311749

+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * 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.
+ */
+package org.onosproject.vtnrsc;
+
+import static com.google.common.base.Preconditions.checkArgument;
+
+import java.util.Objects;
+
+import com.google.common.base.MoreObjects;
+
+/*
+ * Representation of 5 bit load balance identifier for a service function
+ */
+public final class LoadBalanceId {
+
+    private static final byte MAX_ID = 0x1F;
+    private final byte loadBalanceId;
+
+    /**
+     * Default constructor.
+     *
+     * @param loadBalanceId service function chain path's load balance identifier
+     */
+    private LoadBalanceId(byte loadBalanceId) {
+        checkArgument(loadBalanceId <= MAX_ID, "Load balance id should not be more than 5 bit identifier");
+        this.loadBalanceId = (loadBalanceId);
+    }
+
+    /**
+     * Returns the SfcLoadBalanceId by setting its value.
+     *
+     * @param loadBalanceId service function chain path's load balance identifier
+     * @return LoadBalanceId
+     */
+    public static LoadBalanceId of(byte loadBalanceId) {
+        return new LoadBalanceId(loadBalanceId);
+    }
+
+
+    /**
+     * Returns load balance identifier for a service function.
+     *
+     * @return loadBalanceId
+     */
+    public byte loadBalanceId() {
+        return loadBalanceId;
+    }
+
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(loadBalanceId);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (!(obj instanceof LoadBalanceId)) {
+            return false;
+        }
+        final LoadBalanceId other = (LoadBalanceId) obj;
+        return   Objects.equals(this.loadBalanceId, other.loadBalanceId);
+    }
+
+    @Override
+    public String toString() {
+        return MoreObjects.toStringHelper(this)
+                .add("loadBalanceId", loadBalanceId)
+                .toString();
+    }
+}

+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * 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.
+ */
+package org.onosproject.vtnrsc;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.notNullValue;
+import static org.onlab.junit.ImmutableClassChecker.assertThatClassIsImmutable;
+
+import org.junit.Test;
+
+import com.google.common.testing.EqualsTester;
+
+/**
+ * Unit tests for LoadBalanceId class.
+ */
+public class LoadBalanceIdTest {
+
+    final LoadBalanceId id1 = LoadBalanceId.of((byte) 1);
+    final LoadBalanceId sameAsId1 = LoadBalanceId.of((byte) 1);
+    final LoadBalanceId id2 = LoadBalanceId.of((byte) 2);
+
+    /**
+     * Checks that the LoadBalanceId class is immutable.
+     */
+    @Test
+    public void testImmutability() {
+        assertThatClassIsImmutable(LoadBalanceId.class);
+    }
+
+    /**
+     * Checks the operation of equals() methods.
+     */
+    @Test
+    public void testEquals() {
+        new EqualsTester().addEqualityGroup(id1, sameAsId1).addEqualityGroup(id2)
+        .testEquals();
+    }
+
+    /**
+     * Checks the construction of a LoadBalanceId object.
+     */
+    @Test
+    public void testConstruction() {
+        final LoadBalanceId id = LoadBalanceId.of((byte) 1);
+        assertThat(id, is(notNullValue()));
+        assertThat(id.loadBalanceId(), is((byte) 1));
+    }
+}