Merge pull request #2767 from FlyInWind1/no-result-type

Resolve resultType by namespace and id when not provide resultType and resultMap

src/main/java/org/apache/ibatis/builder/annotation/MapperAnnotationBuilder.java

@@ -1,5 +1,5 @@
 /*
- *    Copyright 2009-2022 the original author or authors.
+ *    Copyright 2009-2023 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.
@@ -138,7 +138,7 @@ public void parse() {
     parsePendingMethods();
   }
 
-  private boolean canHaveStatement(Method method) {
+  private static boolean canHaveStatement(Method method) {
     // issue #237
     return !method.isBridge() && !method.isDefault();
   }
@@ -224,7 +224,7 @@ private void parseCacheRef() {
   }
 
   private String parseResultMap(Method method) {
-    Class<?> returnType = getReturnType(method);
+    Class<?> returnType = getReturnType(method, type);
     Arg[] args = method.getAnnotationsByType(Arg.class);
     Result[] results = method.getAnnotationsByType(Result.class);
     TypeDiscriminator typeDiscriminator = method.getAnnotation(TypeDiscriminator.class);
@@ -366,7 +366,7 @@ void parseStatement(Method method) {
           null,
           parameterTypeClass,
           resultMapId,
-          getReturnType(method),
+          getReturnType(method, type),
           resultSetType,
           flushCache,
           useCache,
@@ -408,7 +408,7 @@ private Class<?> getParameterType(Method method) {
     return parameterType;
   }
 
-  private Class<?> getReturnType(Method method) {
+  private static Class<?> getReturnType(Method method, Class<?> type) {
     Class<?> returnType = method.getReturnType();
     Type resolvedReturnType = TypeParameterResolver.resolveReturnType(method, type);
     if (resolvedReturnType instanceof Class) {
@@ -669,6 +669,23 @@ private Optional<AnnotationWrapper> getAnnotationWrapper(Method method, boolean
     return Optional.ofNullable(annotationWrapper);
   }
 
+  public static Class<?> getMethodReturnType(String mapperFqn, String localStatementId) {
+    if (mapperFqn == null || localStatementId == null) {
+      return null;
+    }
+    try {
+      Class<?> mapperClass = Resources.classForName(mapperFqn);
+      for (Method method : mapperClass.getMethods()) {
+        if (method.getName().equals(localStatementId) && canHaveStatement(method)) {
+          return getReturnType(method, mapperClass);
+        }
+      }
+    } catch (ClassNotFoundException e) {
+      // No corresponding mapper interface which is OK
+    }
+    return null;
+  }
+
   private class AnnotationWrapper {
     private final Annotation annotation;
     private final String databaseId;

src/main/java/org/apache/ibatis/builder/xml/XMLStatementBuilder.java

@@ -1,5 +1,5 @@
 /*
- *    Copyright 2009-2022 the original author or authors.
+ *    Copyright 2009-2023 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.
@@ -20,6 +20,7 @@
 
 import org.apache.ibatis.builder.BaseBuilder;
 import org.apache.ibatis.builder.MapperBuilderAssistant;
+import org.apache.ibatis.builder.annotation.MapperAnnotationBuilder;
 import org.apache.ibatis.executor.keygen.Jdbc3KeyGenerator;
 import org.apache.ibatis.executor.keygen.KeyGenerator;
 import org.apache.ibatis.executor.keygen.NoKeyGenerator;
@@ -101,6 +102,9 @@ public void parseStatementNode() {
     String resultType = context.getStringAttribute("resultType");
     Class<?> resultTypeClass = resolveClass(resultType);
     String resultMap = context.getStringAttribute("resultMap");
+    if (resultTypeClass == null && resultMap == null) {
+      resultTypeClass = MapperAnnotationBuilder.getMethodReturnType(builderAssistant.getCurrentNamespace(), id);
+    }
     String resultSetType = context.getStringAttribute("resultSetType");
     ResultSetType resultSetTypeEnum = resolveResultSetType(resultSetType);
     if (resultSetTypeEnum == null) {

src/main/java/org/apache/ibatis/executor/resultset/DefaultResultSetHandler.java

@@ -1,5 +1,5 @@
 /*
- *    Copyright 2009-2022 the original author or authors.
+ *    Copyright 2009-2023 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.
@@ -294,7 +294,7 @@ private void cleanUpAfterHandlingResultSet() {
   private void validateResultMapsCount(ResultSetWrapper rsw, int resultMapCount) {
     if (rsw != null && resultMapCount < 1) {
       throw new ExecutorException("A query was run and no Result Maps were found for the Mapped Statement '" + mappedStatement.getId()
-          + "'.  It's likely that neither a Result Type nor a Result Map was specified.");
+          + "'. 'resultType' or 'resultMap' must be specified when there is no corresponding method.");
     }
   }
 

src/test/java/org/apache/ibatis/submitted/no_result_type_map/Mapper.java

@@ -0,0 +1,28 @@
+/*
+ *    Copyright 2009-2023 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
+ *
+ *       https://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.submitted.no_result_type_map;
+
+import org.apache.ibatis.annotations.Param;
+
+import java.util.List;
+
+public interface Mapper extends ParentMapper<User>{
+
+  User getUser(@Param("id") Integer id);
+
+  List<User> getAllUsers();
+
+}

src/test/java/org/apache/ibatis/submitted/no_result_type_map/NoResultTypeMapTest.java

@@ -0,0 +1,92 @@
+/*
+ *    Copyright 2009-2023 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
+ *
+ *       https://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.submitted.no_result_type_map;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import java.io.Reader;
+import java.util.List;
+
+import org.apache.ibatis.BaseDataTest;
+import org.apache.ibatis.exceptions.PersistenceException;
+import org.apache.ibatis.executor.ExecutorException;
+import org.apache.ibatis.io.Resources;
+import org.apache.ibatis.session.SqlSession;
+import org.apache.ibatis.session.SqlSessionFactory;
+import org.apache.ibatis.session.SqlSessionFactoryBuilder;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+class NoResultTypeMapTest {
+
+  private static SqlSessionFactory sqlSessionFactory;
+
+  @BeforeAll
+  static void setUp() throws Exception {
+    // create a SqlSessionFactory
+    try (Reader reader = Resources
+      .getResourceAsReader("org/apache/ibatis/submitted/no_result_type_map/mybatis-config.xml")) {
+      sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
+      sqlSessionFactory.getConfiguration().addMapper(Mapper.class);
+    }
+
+    // populate in-memory database
+    BaseDataTest.runScript(sqlSessionFactory.getConfiguration().getEnvironment().getDataSource(),
+      "org/apache/ibatis/submitted/no_result_type_map/CreateDB.sql");
+  }
+
+  @Test
+  void shouldGetAUser() {
+    try (SqlSession sqlSession = sqlSessionFactory.openSession()) {
+      Mapper mapper = sqlSession.getMapper(Mapper.class);
+      User user = mapper.getUser(1);
+      Assertions.assertEquals("User1", user.getName());
+    }
+  }
+
+  @Test
+  void shouldGetAllUsers() {
+    try (SqlSession sqlSession = sqlSessionFactory.openSession()) {
+      Mapper mapper = sqlSession.getMapper(Mapper.class);
+      List<User> users = mapper.getAllUsers();
+      Assertions.assertEquals(3, users.size());
+    }
+  }
+
+  @Test
+  void shouldResolveInheritedReturnType() {
+    try (SqlSession sqlSession = sqlSessionFactory.openSession()) {
+      Mapper mapper = sqlSession.getMapper(Mapper.class);
+      List<User> users = mapper.getAllUsersInParent();
+      Assertions.assertEquals(3, users.size());
+    }
+  }
+
+  @Test
+  void shouldFailIfNoMatchingMethod() {
+    try (SqlSession sqlSession = sqlSessionFactory.openSession()) {
+      PersistenceException ex = assertThrows(PersistenceException.class,
+          () -> sqlSession.selectList("org.apache.ibatis.submitted.no_result_type_map.Mapper.noMatchingMethod"));
+      ExecutorException cause = (ExecutorException) ex.getCause();
+      assertEquals("A query was run and no Result Maps were found for the Mapped Statement "
+          + "'org.apache.ibatis.submitted.no_result_type_map.Mapper.noMatchingMethod'. "
+          + "'resultType' or 'resultMap' must be specified when there is no corresponding method.",
+          cause.getMessage());
+    }
+  }
+
+}

src/test/java/org/apache/ibatis/submitted/no_result_type_map/ParentMapper.java

@@ -0,0 +1,24 @@
+/*
+ *    Copyright 2009-2023 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
+ *
+ *       https://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.submitted.no_result_type_map;
+
+import java.util.List;
+
+public interface ParentMapper<T> {
+
+  List<T> getAllUsersInParent();
+
+}

src/test/java/org/apache/ibatis/submitted/no_result_type_map/User.java

@@ -0,0 +1,38 @@
+/*
+ *    Copyright 2009-2023 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
+ *
+ *       https://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.submitted.no_result_type_map;
+
+public class User {
+
+  private Integer id;
+  private String name;
+
+  public Integer getId() {
+    return id;
+  }
+
+  public void setId(Integer id) {
+    this.id = id;
+  }
+
+  public String getName() {
+    return name;
+  }
+
+  public void setName(String name) {
+    this.name = name;
+  }
+}

src/test/resources/org/apache/ibatis/submitted/no_result_type_map/CreateDB.sql

@@ -0,0 +1,26 @@
+--
+--    Copyright 2009-2023 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
+--
+--       https://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.
+--
+
+drop table users if exists;
+
+create table users (
+  id int,
+  name varchar(20)
+);
+
+insert into users (id, name) values(1, 'User1');
+insert into users (id, name) values(2, 'User2');
+insert into users (id, name) values(3, 'User3');

src/test/resources/org/apache/ibatis/submitted/no_result_type_map/Mapper.xml

@@ -0,0 +1,41 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+
+       Copyright 2009-2023 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
+
+          https://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.
+
+-->
+<!DOCTYPE mapper
+    PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
+    "https://mybatis.org/dtd/mybatis-3-mapper.dtd">
+
+<mapper namespace="org.apache.ibatis.submitted.no_result_type_map.Mapper">
+
+  <select id="getUser">
+    select * from users where id = #{id}
+  </select>
+
+  <select id="getAllUsers">
+    select * from users
+  </select>
+
+  <select id="getAllUsersInParent">
+    select * from users
+  </select>
+
+  <select id="noMatchingMethod">
+    select * from users
+  </select>
+
+</mapper>