IGNITE-15188 JDBC driver for 3.0: Database metadata (#339)

modules/client-common/src/main/java/org/apache/ignite/client/proto/query/JdbcQueryEventHandler.java

@@ -19,6 +19,14 @@
 
 import org.apache.ignite.client.proto.query.event.BatchExecuteRequest;
 import org.apache.ignite.client.proto.query.event.BatchExecuteResult;
+import org.apache.ignite.client.proto.query.event.JdbcMetaColumnsRequest;
+import org.apache.ignite.client.proto.query.event.JdbcMetaColumnsResult;
+import org.apache.ignite.client.proto.query.event.JdbcMetaPrimaryKeysRequest;
+import org.apache.ignite.client.proto.query.event.JdbcMetaPrimaryKeysResult;
+import org.apache.ignite.client.proto.query.event.JdbcMetaSchemasRequest;
+import org.apache.ignite.client.proto.query.event.JdbcMetaSchemasResult;
+import org.apache.ignite.client.proto.query.event.JdbcMetaTablesRequest;
+import org.apache.ignite.client.proto.query.event.JdbcMetaTablesResult;
 import org.apache.ignite.client.proto.query.event.QueryCloseRequest;
 import org.apache.ignite.client.proto.query.event.QueryCloseResult;
 import org.apache.ignite.client.proto.query.event.QueryExecuteRequest;
@@ -61,4 +69,36 @@ public interface JdbcQueryEventHandler {
      * @return Result.
      */
     QueryCloseResult close(QueryCloseRequest req);
+
+    /**
+     * {@link JdbcMetaTablesRequest} command handler.
+     *
+     * @param req Jdbc tables metadata request.
+     * @return Result.
+     */
+    JdbcMetaTablesResult tablesMeta(JdbcMetaTablesRequest req);
+
+    /**
+     * {@link JdbcMetaColumnsRequest} command handler.
+     *
+     * @param req Jdbc columns metadata request.
+     * @return Result.
+     */
+    JdbcMetaColumnsResult columnsMeta(JdbcMetaColumnsRequest req);
+
+    /**
+     * {@link JdbcMetaSchemasRequest} command handler.
+     *
+     * @param req Jdbc schemas metadata request.
+     * @return Result.
+     */
+    JdbcMetaSchemasResult schemasMeta(JdbcMetaSchemasRequest req);
+
+    /**
+     * {@link JdbcMetaPrimaryKeysRequest} command handler.
+     *
+     * @param req Jdbc primary keys metadata request.
+     * @return Result.
+     */
+    JdbcMetaPrimaryKeysResult primaryKeysMeta(JdbcMetaPrimaryKeysRequest req);
 }

modules/client-common/src/main/java/org/apache/ignite/client/proto/query/event/ClientMessageUtils.java

@@ -0,0 +1,52 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.ignite.client.proto.query.event;
+
+import org.apache.ignite.internal.client.proto.ClientMessagePacker;
+import org.apache.ignite.internal.client.proto.ClientMessageUnpacker;
+
+/**
+ * Client message utils class.
+ */
+public class ClientMessageUtils {
+    /**
+     * Packs a string or null if string is null.
+     *
+     * @param packer Message packer.
+     * @param str String to serialize.
+     */
+    public static void writeStringNullable(ClientMessagePacker packer, String str) {
+        if (str == null)
+            packer.packNil();
+        else
+            packer.packString(str);
+    }
+
+    /**
+     * Unpack a string or null if no string is presented.
+     *
+     * @param unpacker Message unpacker.
+     * @return String or null.
+     */
+    public static String readStringNullable(ClientMessageUnpacker unpacker) {
+        if (!unpacker.tryUnpackNil())
+            return unpacker.unpackString();
+
+        return null;
+    }
+}