findbugs: pattern in used in split method

plugins/network-elements/bigswitch/src/com/cloud/network/bigswitch/BigSwitchBcfUtils.java

@@ -528,11 +528,13 @@ public class BigSwitchBcfUtils {
         }
     }
 
+    // returns null: should throw something^%*%#&
+    // Integer -> int
     public Integer getSubnetMaskLength(String maskString){
         if(!IPAddress.isValidIPv4(maskString)){
             return null;
         }
-        String[] octets = maskString.split(".");
+        String[] octets = maskString.split("\\.");
         Integer bits = 0;
         for (String o: octets){
             switch(o){

plugins/network-elements/bigswitch/test/com/cloud/network/bigswitch/BigSwitchBcfUtilsTest.java

@@ -0,0 +1,74 @@
+package com.cloud.network.bigswitch;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+import com.cloud.agent.AgentManager;
+import com.cloud.dc.dao.VlanDao;
+import com.cloud.host.dao.HostDao;
+import com.cloud.network.NetworkModel;
+import com.cloud.network.dao.BigSwitchBcfDao;
+import com.cloud.network.dao.FirewallRulesCidrsDao;
+import com.cloud.network.dao.FirewallRulesDao;
+import com.cloud.network.dao.IPAddressDao;
+import com.cloud.network.dao.NetworkDao;
+import com.cloud.network.vpc.NetworkACLItemCidrsDao;
+import com.cloud.network.vpc.NetworkACLItemDao;
+import com.cloud.network.vpc.dao.VpcDao;
+import com.cloud.vm.dao.NicDao;
+import com.cloud.vm.dao.VMInstanceDao;
+
+public class BigSwitchBcfUtilsTest {
+
+    @Mock
+    NetworkDao networkDao;
+    @Mock
+    NicDao nicDao;
+    @Mock
+    VMInstanceDao vmDao;
+    @Mock
+    HostDao hostDao;
+    @Mock
+    VpcDao vpcDao;
+    @Mock
+    BigSwitchBcfDao bigswitchBcfDao;
+    @Mock
+    AgentManager agentMgr;
+    @Mock
+    VlanDao vlanDao;
+    @Mock
+    IPAddressDao ipAddressDao;
+    @Mock
+    FirewallRulesDao fwRulesDao;
+    @Mock
+    FirewallRulesCidrsDao fwCidrsDao;
+    @Mock
+    NetworkACLItemDao aclItemDao;
+    @Mock
+    NetworkACLItemCidrsDao aclItemCidrsDao;
+    @Mock
+    NetworkModel networkModel;
+    @Mock
+    BigSwitchBcfUtils bsUtil;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+        bsUtil = new BigSwitchBcfUtils(networkDao, nicDao, vmDao, hostDao,
+                vpcDao, bigswitchBcfDao, agentMgr, vlanDao, ipAddressDao,
+                fwRulesDao, fwCidrsDao, aclItemDao, aclItemCidrsDao,
+                networkModel);
+    }
+
+    @Test
+    public void getSubnetMaskLengthTest() {
+        Integer rc = bsUtil.getSubnetMaskLength("255.255.255.254");
+        assertEquals("failed", new Integer(31), rc);
+        rc = bsUtil.getSubnetMaskLength("128.255.255.254");
+        assertEquals("failed", new Integer(1), rc);
+    }
+}