Throw correct exception type while constructing session and transaction (#229)

## What is the goal of this PR?

We have fixed a bug which caused incorrect exception type being thrown while constructing session and transaction.

## What are the changes implemented in this PR?

- Catch `StatusRuntimeException` and convert it to `GraknClientException` in `Session` and `Transaction` constructor.

Author: lriuui0x0

rpc/RPCSession.java

@@ -24,9 +24,11 @@
 import grakn.client.Grakn.Transaction;
 import grakn.client.GraknClient;
 import grakn.client.GraknOptions;
+import grakn.client.common.exception.GraknClientException;
 import grakn.protocol.GraknGrpc;
 import grakn.protocol.SessionProto;
 import io.grpc.Channel;
+import io.grpc.StatusRuntimeException;
 
 import java.util.Timer;
 import java.util.TimerTask;
@@ -45,18 +47,22 @@ public class RPCSession implements Session {
     private final GraknGrpc.GraknBlockingStub blockingGrpcStub;
 
     public RPCSession(GraknClient client, String database, Type type, GraknOptions options) {
-        this.channel = client.channel();
-        this.database = database;
-        this.type = type;
-        blockingGrpcStub = GraknGrpc.newBlockingStub(channel);
-
-        final SessionProto.Session.Open.Req openReq = SessionProto.Session.Open.Req.newBuilder()
-                .setDatabase(database).setType(sessionType(type)).setOptions(options(options)).build();
-
-        sessionId = blockingGrpcStub.sessionOpen(openReq).getSessionId();
-        pulse = new Timer();
-        isOpen = new AtomicBoolean(true);
-        pulse.scheduleAtFixedRate(this.new PulseTask(), 0, 5000);
+        try {
+            this.channel = client.channel();
+            this.database = database;
+            this.type = type;
+            blockingGrpcStub = GraknGrpc.newBlockingStub(channel);
+
+            final SessionProto.Session.Open.Req openReq = SessionProto.Session.Open.Req.newBuilder()
+                    .setDatabase(database).setType(sessionType(type)).setOptions(options(options)).build();
+
+            sessionId = blockingGrpcStub.sessionOpen(openReq).getSessionId();
+            pulse = new Timer();
+            isOpen = new AtomicBoolean(true);
+            pulse.scheduleAtFixedRate(this.new PulseTask(), 0, 5000);
+        } catch (StatusRuntimeException e) {
+            throw new GraknClientException(e);
+        }
     }
 
     @Override
@@ -83,7 +89,11 @@ public boolean isOpen() {
     public void close() {
         if (isOpen.compareAndSet(true, false)) {
             pulse.cancel();
-            blockingGrpcStub.sessionClose(SessionProto.Session.Close.Req.newBuilder().setSessionId(sessionId).build());
+            try {
+                blockingGrpcStub.sessionClose(SessionProto.Session.Close.Req.newBuilder().setSessionId(sessionId).build());
+            } catch (StatusRuntimeException e) {
+                throw new GraknClientException(e);
+            }
         }
     }
 

rpc/RPCTransaction.java

@@ -63,25 +63,29 @@ public class RPCTransaction implements Transaction {
     private final AtomicBoolean isOpen;
 
     RPCTransaction(RPCSession session, ByteString sessionId, Type type, GraknOptions options) {
-        this.type = type;
-        conceptManager = new ConceptManager(this);
-        logicManager = new LogicManager(this);
-        queryManager = new QueryManager(this);
-        collectors = new ResponseCollectors();
-
-        // Opening the StreamObserver exposes these atomics to another thread, so we must initialize them first.
-        isOpen = new AtomicBoolean(true);
-        requestObserver = GraknGrpc.newStub(session.channel()).transaction(responseObserver());
-        final TransactionProto.Transaction.Req.Builder openRequest = TransactionProto.Transaction.Req.newBuilder()
-                .putAllMetadata(tracingData())
-                .setOpenReq(TransactionProto.Transaction.Open.Req.newBuilder()
-                        .setSessionId(sessionId)
-                        .setType(TransactionProto.Transaction.Type.forNumber(type.id()))
-                        .setOptions(options(options)));
-        final Instant startTime = Instant.now();
-        final TransactionProto.Transaction.Open.Res res = execute(openRequest).getOpenRes();
-        final Instant endTime = Instant.now();
-        networkLatencyMillis = (int) ChronoUnit.MILLIS.between(startTime, endTime) - res.getProcessingTimeMillis();
+        try {
+            this.type = type;
+            conceptManager = new ConceptManager(this);
+            logicManager = new LogicManager(this);
+            queryManager = new QueryManager(this);
+            collectors = new ResponseCollectors();
+
+            // Opening the StreamObserver exposes these atomics to another thread, so we must initialize them first.
+            isOpen = new AtomicBoolean(true);
+            requestObserver = GraknGrpc.newStub(session.channel()).transaction(responseObserver());
+            final TransactionProto.Transaction.Req.Builder openRequest = TransactionProto.Transaction.Req.newBuilder()
+                    .putAllMetadata(tracingData())
+                    .setOpenReq(TransactionProto.Transaction.Open.Req.newBuilder()
+                            .setSessionId(sessionId)
+                            .setType(TransactionProto.Transaction.Type.forNumber(type.id()))
+                            .setOptions(options(options)));
+            final Instant startTime = Instant.now();
+            final TransactionProto.Transaction.Open.Res res = execute(openRequest).getOpenRes();
+            final Instant endTime = Instant.now();
+            networkLatencyMillis = (int) ChronoUnit.MILLIS.between(startTime, endTime) - res.getProcessingTimeMillis();
+        } catch (StatusRuntimeException e) {
+            throw new GraknClientException(e);
+        }
     }
 
     @Override
@@ -137,7 +141,11 @@ public void close() {
     private void close(Response.Done doneResponse) {
         if (isOpen.compareAndSet(true, false)) {
             collectors.clear(doneResponse);
-            requestObserver.onCompleted();
+            try {
+                requestObserver.onCompleted();
+            } catch (StatusRuntimeException e) {
+                throw new GraknClientException(e);
+            }
         }
     }