1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18 package org.apache.shardingsphere.proxy.backend.handler;
19
20 import org.apache.shardingsphere.proxy.backend.response.data.QueryResponseRow;
21 import org.apache.shardingsphere.proxy.backend.response.header.ResponseHeader;
22
23 import java.sql.SQLException;
24 import java.util.Collections;
25
26 /**
27 * Proxy backend handler.
28 */
29 public interface ProxyBackendHandler {
30
31 /**
32 * Execute command.
33 *
34 * @return backend response
35 * @throws SQLException SQL exception
36 */
37 ResponseHeader execute() throws SQLException;
38
39 /**
40 * Goto next result value.
41 *
42 * @return has more result value or not
43 * @throws SQLException SQL exception
44 */
45 default boolean next() throws SQLException {
46 return false;
47 }
48
49 /**
50 * Get row data.
51 *
52 * @return row data
53 * @throws SQLException SQL exception
54 */
55 default QueryResponseRow getRowData() throws SQLException {
56 return new QueryResponseRow(Collections.emptyList());
57 }
58
59 /**
60 * Close.
61 *
62 * @throws SQLException SQL exception
63 */
64 default void close() throws SQLException {
65 }
66 }