Remove check for not empty seednodes (can be empty in some cases)

network/src/main/java/io/bitsquare/p2p/peers/PeerManager.java

@@ -93,6 +93,7 @@ public class PeerManager implements ConnectionListener {
     public PeerManager(NetworkNode networkNode, Set<NodeAddress> seedNodeAddresses, File storageDir, Clock clock) {
         this.networkNode = networkNode;
         this.clock = clock;
+        // seedNodeAddresses can be empty (in case there is only 1 seed node, the seed node starting up has no other seed nodes)
         this.seedNodeAddresses = new HashSet<>(seedNodeAddresses);
         networkNode.addConnectionListener(this);
         dbStorage = new Storage<>(storageDir);

network/src/main/java/io/bitsquare/p2p/peers/getdata/RequestDataManager.java

@@ -69,10 +69,10 @@ public class RequestDataManager implements MessageListener, ConnectionListener,
         this.networkNode = networkNode;
         this.dataStorage = dataStorage;
         this.peerManager = peerManager;
+        // seedNodeAddresses can be empty (in case there is only 1 seed node, the seed node starting up has no other seed nodes)
         this.seedNodeAddresses = new HashSet<>(seedNodeAddresses);
         this.listener = listener;
 
-        checkArgument(!seedNodeAddresses.isEmpty(), "seedNodeAddresses must not be empty.");
         networkNode.addMessageListener(this);
         peerManager.addListener(this);
     }
@@ -94,22 +94,26 @@ public class RequestDataManager implements MessageListener, ConnectionListener,
     public void requestPreliminaryData() {
         Log.traceCall();
         ArrayList<NodeAddress> nodeAddresses = new ArrayList<>(seedNodeAddresses);
+        if (!nodeAddresses.isEmpty()) {
             Collections.shuffle(nodeAddresses);
             NodeAddress nextCandidate = nodeAddresses.get(0);
             nodeAddresses.remove(nextCandidate);
             requestData(nextCandidate, nodeAddresses);
         }
+    }
 
     public void requestUpdateData() {
         Log.traceCall();
         checkArgument(nodeAddressOfPreliminaryDataRequest.isPresent(), "seedNodeOfPreliminaryDataRequest must be present");
         dataUpdateRequested = true;
         List<NodeAddress> remainingNodeAddresses = new ArrayList<>(seedNodeAddresses);
+        if (!remainingNodeAddresses.isEmpty()) {
             Collections.shuffle(remainingNodeAddresses);
             NodeAddress candidate = nodeAddressOfPreliminaryDataRequest.get();
             remainingNodeAddresses.remove(candidate);
             requestData(candidate, remainingNodeAddresses);
         }
+    }
 
     public Optional<NodeAddress> getNodeAddressOfPreliminaryDataRequest() {
         return nodeAddressOfPreliminaryDataRequest;
@@ -315,10 +319,11 @@ public class RequestDataManager implements MessageListener, ConnectionListener,
                         List<NodeAddress> filteredPersistedPeers = getFilteredNonSeedNodeList(getSortedNodeAddresses(peerManager.getPersistedPeers()), list);
                         list.addAll(filteredPersistedPeers);
 
-                        checkArgument(!list.isEmpty(), "seedNodeAddresses must not be empty.");
+                        if (!list.isEmpty()) {
                             NodeAddress nextCandidate = list.get(0);
                             list.remove(nextCandidate);
                             requestData(nextCandidate, list);
+                        }
                     },
                     RETRY_DELAY_SEC);
         }

network/src/main/java/io/bitsquare/p2p/peers/peerexchange/PeerExchangeManager.java

@@ -16,7 +16,6 @@ import java.util.*;
 import java.util.concurrent.TimeUnit;
 import java.util.stream.Collectors;
 
-import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.base.Preconditions.checkNotNull;
 
 public class PeerExchangeManager implements MessageListener, ConnectionListener, PeerManager.Listener {
@@ -41,7 +40,7 @@ public class PeerExchangeManager implements MessageListener, ConnectionListener,
     public PeerExchangeManager(NetworkNode networkNode, PeerManager peerManager, Set<NodeAddress> seedNodeAddresses) {
         this.networkNode = networkNode;
         this.peerManager = peerManager;
-        checkArgument(!seedNodeAddresses.isEmpty(), "seedNodeAddresses must not be empty");
+        // seedNodeAddresses can be empty (in case there is only 1 seed node, the seed node starting up has no other seed nodes)
         this.seedNodeAddresses = new HashSet<>(seedNodeAddresses);
 
         networkNode.addMessageListener(this);

network/src/main/java/io/bitsquare/p2p/seed/SeedNodesRepository.java

@@ -32,15 +32,15 @@ public class SeedNodesRepository {
             new NodeAddress("izs5oz7i5ta7c2ir.onion:8000"),*/
 
             // v0.3.5, v0.3.6 (backwards compatible)
-            new NodeAddress("hulvbm5xjn7b7ku4.onion:8000"),
+            /*new NodeAddress("hulvbm5xjn7b7ku4.onion:8000"),
             new NodeAddress("3efgjjbdvhbvck3x.onion:8000"),
-            new NodeAddress("3unfcshgwipxhxfm.onion:8000"),
+            new NodeAddress("3unfcshgwipxhxfm.onion:8000"),*/
 
 
             // v0.3.7
-           /* new NodeAddress("ybmi4iaesugslxrw.onion:8000"),
+            new NodeAddress("ybmi4iaesugslxrw.onion:8000"),
             new NodeAddress("ufwnvo775jfnjeux.onion:8000"),
-            new NodeAddress("b66vnevaljo6xt5a.onion:8000"),*/
+            new NodeAddress("b66vnevaljo6xt5a.onion:8000"),
 
             // testnet
             new NodeAddress("znmy44wcstn2rkva.onion:8001"),