1 /*
2 * Copyright 2009-2023 the original author or authors.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * https://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16 package org.apache.ibatis.builder.annotation;
17
18 import java.lang.reflect.Method;
19 import java.util.Arrays;
20 import java.util.List;
21 import java.util.stream.Collectors;
22
23 import org.apache.ibatis.builder.BuilderException;
24
25 /**
26 * The interface that resolve an SQL provider method via an SQL provider class.
27 * <p>
28 * This interface need to implements at an SQL provider class and it need to define the default constructor for creating
29 * a new instance.
30 *
31 * @since 3.5.1
32 *
33 * @author Kazuki Shimizu
34 */
35 public interface ProviderMethodResolver {
36
37 /**
38 * Resolve an SQL provider method.
39 * <p>
40 * The default implementation return a method that matches following conditions.
41 * <ul>
42 * <li>Method name matches with mapper method</li>
43 * <li>Return type matches the {@link CharSequence}({@link String}, {@link StringBuilder}, etc...)</li>
44 * </ul>
45 * If matched method is zero or multiple, it throws a {@link BuilderException}.
46 *
47 * @param context
48 * a context for SQL provider
49 *
50 * @return an SQL provider method
51 *
52 * @throws BuilderException
53 * Throws when cannot resolve a target method
54 */
55 default Method resolveMethod(ProviderContext context) {
56 List<Method> sameNameMethods = Arrays.stream(getClass().getMethods())
57 .filter(m -> m.getName().equals(context.getMapperMethod().getName())).collect(Collectors.toList());
58 if (sameNameMethods.isEmpty()) {
59 throw new BuilderException("Cannot resolve the provider method because '" + context.getMapperMethod().getName()
60 + "' not found in SqlProvider '" + getClass().getName() + "'.");
61 }
62 List<Method> targetMethods = sameNameMethods.stream()
63 .filter(m -> CharSequence.class.isAssignableFrom(m.getReturnType())).collect(Collectors.toList());
64 if (targetMethods.size() == 1) {
65 return targetMethods.get(0);
66 }
67 if (targetMethods.isEmpty()) {
68 throw new BuilderException("Cannot resolve the provider method because '" + context.getMapperMethod().getName()
69 + "' does not return the CharSequence or its subclass in SqlProvider '" + getClass().getName() + "'.");
70 }
71 throw new BuilderException("Cannot resolve the provider method because '" + context.getMapperMethod().getName()
72 + "' is found multiple in SqlProvider '" + getClass().getName() + "'.");
73 }
74
75 }