1 package org.apache.maven.search.backend.smo.internal;
2
3 /*
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 import java.io.IOException;
23 import java.io.InputStream;
24 import java.util.Properties;
25
26 import org.apache.maven.search.SearchRequest;
27
28 /**
29 * A trivial "transport abstraction" to make possible pluggable implementations.
30 */
31 public abstract class SmoSearchTransportSupport
32 {
33 private final String clientVersion;
34
35 public SmoSearchTransportSupport()
36 {
37 this.clientVersion = discoverVersion();
38 }
39
40 private String discoverVersion()
41 {
42 Properties properties = new Properties();
43 InputStream inputStream = getClass().getClassLoader().getResourceAsStream( "smo-version.properties" );
44 if ( inputStream != null )
45 {
46 try ( InputStream is = inputStream )
47 {
48 properties.load( is );
49 }
50 catch ( IOException e )
51 {
52 // fall through
53 }
54 }
55 return properties.getProperty( "version", "unknown" );
56 }
57
58 /**
59 * Exposes this backend version, for example to be used in HTTP {@code User-Agent} string, never {@code null}.
60 */
61 protected String getClientVersion()
62 {
63 return clientVersion;
64 }
65
66 /**
67 * Exposes full HTTP {@code User-Agent} string ready to be used by HTTP clients, never {@code null}.
68 */
69 protected String getUserAgent()
70 {
71 return "Apache Search SMO/" + getClientVersion();
72 }
73
74 /**
75 * This method should issue a HTTP GET requests using {@code serviceUri} and return body payload as {@link String}
76 * ONLY if the response was HTTP 200 Ok and there was a payload returned by service. In any other case, it should
77 * throw, never return {@code null}. The payload is expected to be {@code application/json}, so client may add
78 * headers to request. Also, the payload is expected to be "relatively small".
79 */
80 public abstract String fetch( SearchRequest searchRequest, String serviceUri ) throws IOException;
81 }