Ensured that ServerAddressSelector.choose returns either a List with a single ok ServerDescription, or else an empty list.

Ensured that an attempt to invalidate a server after an error doesn't fail if that server has already been removed from the cluster description.

      JAVA-1634

Author: jyemin

src/main/com/mongodb/ClusterDescription.java

@@ -86,7 +86,7 @@ public Set<ServerDescription> getAll() {
 
     public ServerDescription getByServerAddress(final ServerAddress serverAddress) {
         for (ServerDescription cur : getAll()) {
-            if (cur.getAddress().equals(serverAddress)) {
+            if (cur.isOk() && cur.getAddress().equals(serverAddress)) {
                 return cur;
             }
         }

src/main/com/mongodb/DBTCPConnector.java

@@ -30,6 +30,7 @@
 import static com.mongodb.ClusterType.Unknown;
 import static com.mongodb.MongoAuthority.Type.Set;
 import static java.util.concurrent.TimeUnit.MILLISECONDS;
+import static java.util.concurrent.TimeUnit.NANOSECONDS;
 import static org.bson.util.Assertions.isTrue;
 
 /**
@@ -479,7 +480,12 @@ void done( DBPort port ) {
          */
         void error( DBPort port , Exception e ){
             if (!(e instanceof InterruptedIOException)) {
-                getServer(new ServerAddressSelector(port.getAddress())).invalidate();
+                try {
+                    // no need to wait if the server is no longer available
+                    cluster.getServer(new ServerAddressSelector(port.getAddress()), 1, NANOSECONDS).invalidate();
+                } catch (MongoTimeoutException timeoutException) {
+                    // ignore this if the server is already no longer available
+                }
             }
             port.close();
             pinnedRequestStatusThreadLocal.remove();

src/main/com/mongodb/ServerAddressSelector.java

@@ -17,6 +17,7 @@
 package com.mongodb;
 
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
 
 class ServerAddressSelector implements ServerSelector {
@@ -28,6 +29,10 @@ public ServerAddressSelector(final ServerAddress address) {
 
     @Override
     public List<ServerDescription> choose(final ClusterDescription clusterDescription) {
-        return Arrays.asList(clusterDescription.getByServerAddress(address));
+        ServerDescription serverDescription = clusterDescription.getByServerAddress(address);
+        if (serverDescription != null) {
+            return Arrays.asList(serverDescription);
+        }
+        return Collections.emptyList();
     }
 }

src/test/com/mongodb/ClusterDescriptionTest.java

@@ -39,6 +39,7 @@
 import static java.util.Arrays.asList;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 
 public class ClusterDescriptionTest {
@@ -111,6 +112,12 @@ public void testPrimaryOrSecondary() throws UnknownHostException {
                                                                                                     new Tag("bar", "2")))));
     }
 
+    @Test
+    public void testServerAddress(){
+        assertEquals(primary, cluster.getByServerAddress(primary.getAddress()));
+        assertNull(cluster.getByServerAddress(notOkMember.getAddress()));
+    }
+
     @Test
     public void testSortingOfAll() throws UnknownHostException {
         ClusterDescription description =

src/test/com/mongodb/ServerAddressSelectorTest.java

@@ -0,0 +1,43 @@
+package com.mongodb;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import java.net.UnknownHostException;
+import java.util.Collections;
+
+import static com.mongodb.ServerConnectionState.Connected;
+import static com.mongodb.ServerDescription.builder;
+import static java.util.Arrays.asList;
+import static org.junit.Assert.assertEquals;
+
+public class ServerAddressSelectorTest {
+
+    private ClusterDescription clusterDescription;
+    private ServerDescription goodServer;
+    private ServerDescription badServer;
+
+
+    @Before
+    public void setUp() throws UnknownHostException {
+        goodServer = builder().ok(true).state(Connected).address(new ServerAddress("localhost", 27018)).build();
+        badServer = builder().ok(false).state(Connected).address(new ServerAddress("localhost", 27019)).build();
+        clusterDescription = new ClusterDescription(ClusterConnectionMode.Multiple, ClusterType.ReplicaSet,
+                                                    asList(goodServer, badServer));
+    }
+
+    @Test
+    public void shouldFindServerDescriptionForServerAddress() throws UnknownHostException {
+        assertEquals(new ServerAddressSelector(new ServerAddress("localhost", 27018)).choose(clusterDescription), asList(goodServer));
+    }
+
+    @Test
+    public void shouldNotFindServerDescriptionForServerAddressThatIsNotOk() throws UnknownHostException {
+        assertEquals(new ServerAddressSelector(new ServerAddress("localhost", 27019)).choose(clusterDescription), Collections.emptyList());
+    }
+
+    @Test
+    public void shouldNotFindServerDescriptionForServerAddressThatIsNotInClusterDescription() throws UnknownHostException {
+        assertEquals(new ServerAddressSelector(new ServerAddress("localhost", 27017)).choose(clusterDescription), Collections.emptyList());
+    }
+}