Automatically fall back to bolt protocol

Author: jsoref

cypher-shell/src/integration-test/java/org/neo4j/shell/commands/CypherShellProtocolIntegrationTest.java

@@ -0,0 +1,24 @@
+package org.neo4j.shell.commands;
+
+import org.junit.Test;
+
+import org.neo4j.shell.ConnectionConfig;
+import org.neo4j.shell.CypherShell;
+import org.neo4j.shell.ShellParameterMap;
+import org.neo4j.shell.StringLinePrinter;
+import org.neo4j.shell.cli.Format;
+import org.neo4j.shell.prettyprint.PrettyConfig;
+import static org.junit.Assert.assertTrue;
+
+import static org.neo4j.shell.DatabaseManager.ABSENT_DB_NAME;
+
+public class CypherShellProtocolIntegrationTest{
+
+    @Test
+    public void shouldConnectWithNeo4jProtocol() throws Exception {
+        CypherShell shell = new CypherShell( new StringLinePrinter(), new PrettyConfig( Format.PLAIN, true, 1000), false, new ShellParameterMap());
+        // This should work even on older databases without the neo4j protocol, by falling back to bolt
+        shell.connect( new ConnectionConfig( "neo4j://", "localhost", 7687, "neo4j", "neo", false, ABSENT_DB_NAME ) );
+        assertTrue(shell.isConnected());
+    }
+}

cypher-shell/src/main/java/org/neo4j/shell/state/BoltStateHandler.java

@@ -26,6 +26,7 @@
 import org.neo4j.driver.Values;
 import org.neo4j.driver.exceptions.ClientException;
 import org.neo4j.driver.exceptions.SessionExpiredException;
+import org.neo4j.driver.internal.DriverFactory;
 import org.neo4j.driver.summary.DatabaseInfo;
 import org.neo4j.driver.summary.ResultSummary;
 import org.neo4j.function.ThrowingAction;
@@ -155,9 +156,25 @@ public void connect( @Nonnull ConnectionConfig connectionConfig, ThrowingAction<
         }
         final AuthToken authToken = AuthTokens.basic(connectionConfig.username(), connectionConfig.password());
         try {
-            setActiveDatabase(connectionConfig.database());
-            driver = getDriver(connectionConfig, authToken);
-            reconnect(command);
+            try {
+                setActiveDatabase(connectionConfig.database());
+                driver = getDriver(connectionConfig, authToken);
+                reconnect(command);
+            } catch (org.neo4j.driver.exceptions.ServiceUnavailableException e) {
+                if (!connectionConfig.scheme().equals(DriverFactory.BOLT_ROUTING_URI_SCHEME + "://")) {
+                    throw e;
+                }
+                connectionConfig = new ConnectionConfig(
+                    DriverFactory.BOLT_URI_SCHEME + "://",
+                    connectionConfig.host(),
+                    connectionConfig.port(),
+                    connectionConfig.username(),
+                    connectionConfig.password(),
+                    connectionConfig.encryption(),
+                    connectionConfig.database());
+                driver = getDriver(connectionConfig, authToken);
+                reconnect();
+            }
         } catch (Throwable t) {
             try {
                 silentDisconnect();

cypher-shell/src/test/java/org/neo4j/shell/state/BoltStateHandlerTest.java

@@ -20,6 +20,7 @@
 import org.neo4j.driver.Value;
 import org.neo4j.driver.exceptions.ClientException;
 import org.neo4j.driver.exceptions.SessionExpiredException;
+import org.neo4j.driver.internal.DriverFactory;
 import org.neo4j.driver.summary.DatabaseInfo;
 import org.neo4j.driver.summary.ResultSummary;
 import org.neo4j.driver.summary.ServerInfo;
@@ -416,6 +417,27 @@ public void turnOnEncryptionIfRequested() throws CommandException {
         assertTrue(provider.config.encrypted());
     }
 
+    @Test
+    public void fallbackToBolt() throws CommandException {
+        final String[] uriScheme = new String[1];
+        RecordingDriverProvider provider = new RecordingDriverProvider() {
+            @Override
+            public Driver apply(String uri, AuthToken authToken, Config config) {
+                uriScheme[0] = uri.substring(0, uri.indexOf(':'));
+                if (uriScheme[0].equals("neo4j")) {
+                    throw new org.neo4j.driver.exceptions.ServiceUnavailableException("Please fall back");
+                }
+                super.apply(uri, authToken, config);
+                return new FakeDriver();
+            }
+        };
+        BoltStateHandler handler = new BoltStateHandler(provider, false);
+        ConnectionConfig config = new ConnectionConfig("neo4j://", "", -1, "", "", false, ABSENT_DB_NAME);
+        handler.connect(config);
+
+        assertEquals("bolt", uriScheme[0]);
+    }
+
     private Driver stubResultSummaryInAnOpenSession(Result resultMock, Session sessionMock, String version) {
         return stubResultSummaryInAnOpenSession(resultMock, sessionMock, version, DEFAULT_DEFAULT_DB_NAME);
     }