~~~ /** * Copyright 2009-2019 the original author or authors. * * Licensed 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.ibatis.builder.annotation; import java.lang.reflect.Method; import java.util.Arrays; import java.util.List; import java.util.stream.Collectors; import org.apache.ibatis.builder.BuilderException; /** * The interface that resolve an SQL provider method via an SQL provider class. * * <p> This interface need to implements at an SQL provider class and * it need to define the default constructor for creating a new instance. * * @since 3.5.1 * @author Kazuki Shimizu */ public interface ProviderMethodResolver { /** * Resolve an SQL provider method. * * <p> The default implementation return a method that matches following conditions. * <ul> * <li>Method name matches with mapper method</li> * <li>Return type matches the {@link CharSequence}({@link String}, {@link StringBuilder}, etc...)</li> * </ul> * If matched method is zero or multiple, it throws a {@link BuilderException}. * * @param context a context for SQL provider * @return an SQL provider method * @throws BuilderException Throws when cannot resolve a target method */ default Method resolveMethod(ProviderContext context) { List<Method> sameNameMethods = Arrays.stream(getClass().getMethods()) .filter(m -> m.getName().equals(context.getMapperMethod().getName())) .collect(Collectors.toList()); if (sameNameMethods.isEmpty()) { throw new BuilderException("Cannot resolve the provider method because '" + context.getMapperMethod().getName() + "' not found in SqlProvider '" + getClass().getName() + "'."); } List<Method> targetMethods = sameNameMethods.stream() .filter(m -> CharSequence.class.isAssignableFrom(m.getReturnType())) .collect(Collectors.toList()); if (targetMethods.size() == 1) { return targetMethods.get(0); } if (targetMethods.isEmpty()) { throw new BuilderException("Cannot resolve the provider method because '" + context.getMapperMethod().getName() + "' does not return the CharSequence or its subclass in SqlProvider '" + getClass().getName() + "'."); } else { throw new BuilderException("Cannot resolve the provider method because '" + context.getMapperMethod().getName() + "' is found multiple in SqlProvider '" + getClass().getName() + "'."); } } } ~~~