Fix SCTL statement execute error with comments (#3093)

* Fix SCTL statement execute error with comment

* Add  SCTLUtils class to trim sql

sharding-proxy/sharding-proxy-backend/src/main/java/org/apache/shardingsphere/shardingproxy/backend/text/TextProtocolBackendHandlerFactory.java

@@ -38,6 +38,7 @@ import org.apache.shardingsphere.shardingproxy.backend.text.admin.UnicastBackend
 import org.apache.shardingsphere.shardingproxy.backend.text.admin.UseDatabaseBackendHandler;
 import org.apache.shardingsphere.shardingproxy.backend.text.query.QueryBackendHandler;
 import org.apache.shardingsphere.shardingproxy.backend.text.sctl.ShardingCTLBackendHandlerFactory;
+import org.apache.shardingsphere.shardingproxy.backend.text.sctl.utils.SCTLUtils;
 import org.apache.shardingsphere.shardingproxy.backend.text.transaction.SkipBackendHandler;
 import org.apache.shardingsphere.shardingproxy.backend.text.transaction.TransactionBackendHandler;
 import org.apache.shardingsphere.spi.database.DatabaseType;
@@ -60,8 +61,9 @@ public final class TextProtocolBackendHandlerFactory {
      * @return instance of text protocol backend handler
      */
     public static TextProtocolBackendHandler newInstance(final DatabaseType databaseType, final String sql, final BackendConnection backendConnection) {
-        if (sql.toUpperCase().startsWith(ShardingCTLBackendHandlerFactory.SCTL)) {
-            return ShardingCTLBackendHandlerFactory.newInstance(sql, backendConnection);
+        final String trimSql = SCTLUtils.trimComment(sql);
+        if (trimSql.toUpperCase().startsWith(ShardingCTLBackendHandlerFactory.SCTL)) {
+            return ShardingCTLBackendHandlerFactory.newInstance(trimSql, backendConnection);
         }
         SQLStatement sqlStatement = new SQLParseKernel(ParseRuleRegistry.getInstance(), databaseType, sql).parse();
         if (sqlStatement instanceof TCLStatement) {

sharding-proxy/sharding-proxy-backend/src/main/java/org/apache/shardingsphere/shardingproxy/backend/text/sctl/utils/SCTLUtils.java

+/*
+ * 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.shardingsphere.shardingproxy.backend.text.sctl.utils;
+
+public class SCTLUtils {
+
+    private static final String COMMENT_PREFIX = "/*";
+
+    private static final String COMMENT_SUFFIX = "*/";
+
+    private static final String SQL_END = ";";
+
+    /**
+     * Trim the comment of sql.
+     *
+     * @param sql SQL to be trim
+     * @return the sql remove comment
+     */
+    public static String trimComment(final String sql) {
+        String result = sql;
+        if (sql.startsWith(COMMENT_PREFIX)) {
+            result = result.substring(sql.indexOf(COMMENT_SUFFIX) + 2);
+        }
+        if (sql.endsWith(SQL_END)) {
+            result = result.substring(0, result.length() - 1);
+        }
+        return result.trim();
+    }
+}

sharding-proxy/sharding-proxy-backend/src/test/java/org/apache/shardingsphere/shardingproxy/backend/TextProtocolBackendHandlerFactoryTest.java

@@ -30,6 +30,7 @@ import org.apache.shardingsphere.shardingproxy.backend.text.admin.UnicastBackend
 import org.apache.shardingsphere.shardingproxy.backend.text.admin.UseDatabaseBackendHandler;
 import org.apache.shardingsphere.shardingproxy.backend.text.query.QueryBackendHandler;
 import org.apache.shardingsphere.shardingproxy.backend.text.sctl.set.ShardingCTLSetBackendHandler;
+import org.apache.shardingsphere.shardingproxy.backend.text.sctl.show.ShardingCTLShowBackendHandler;
 import org.apache.shardingsphere.shardingproxy.backend.text.transaction.SkipBackendHandler;
 import org.apache.shardingsphere.shardingproxy.backend.text.transaction.TransactionBackendHandler;
 import org.apache.shardingsphere.spi.database.DatabaseType;
@@ -70,6 +71,13 @@ public final class TextProtocolBackendHandlerFactoryTest {
         TextProtocolBackendHandler actual = TextProtocolBackendHandlerFactory.newInstance(databaseType, sql, backendConnection);
         assertThat(actual, instanceOf(ShardingCTLSetBackendHandler.class));
     }
+
+    @Test
+    public void assertNewInstanceSCTLWithComment() {
+        String sql = "/*ApplicationName=DataGrip 2018.1.4*/ sctl:show cached_connections;";
+        TextProtocolBackendHandler actual = TextProtocolBackendHandlerFactory.newInstance(databaseType, sql, backendConnection);
+        assertThat(actual, instanceOf(ShardingCTLShowBackendHandler.class));
+    }
     
     @Test
     public void assertNewInstanceWithBegin() {