Allow using actual argument name as bind parameter on a single collection

src/main/java/org/apache/ibatis/reflection/ParamNameResolver.java

@@ -27,6 +27,7 @@
 import org.apache.ibatis.session.Configuration;
 import org.apache.ibatis.session.ResultHandler;
 import org.apache.ibatis.session.RowBounds;
+import org.apache.ibatis.session.defaults.DefaultSqlSession;
 
 public class ParamNameResolver {
 
@@ -48,6 +49,7 @@ public class ParamNameResolver {
   private final SortedMap<Integer, String> names;
 
   private boolean hasParamAnnotation;
+  private boolean useActualParamName;
 
   public ParamNameResolver(Configuration config, Method method) {
     final Class<?>[] paramTypes = method.getParameterTypes();
@@ -77,6 +79,8 @@ public ParamNameResolver(Configuration config, Method method) {
           // use the parameter index as the name ("0", "1", ...)
           // gcode issue #71
           name = String.valueOf(map.size());
+        } else {
+          useActualParamName = true;
         }
       }
       map.put(paramIndex, name);
@@ -115,7 +119,12 @@ public Object getNamedParams(Object[] args) {
     if (args == null || paramCount == 0) {
       return null;
     } else if (!hasParamAnnotation && paramCount == 1) {
-      return args[names.firstKey()];
+      Object value = args[names.firstKey()];
+      if (useActualParamName) {
+        return DefaultSqlSession.wrapCollection(value, map -> map.put(names.get(0), value));
+      } else {
+        return value;
+      }
     } else {
       final Map<String, Object> param = new ParamMap<Object>();
       int i = 0;

src/main/java/org/apache/ibatis/session/defaults/DefaultSqlSession.java

@@ -1,5 +1,5 @@
 /**
- *    Copyright 2009-2017 the original author or authors.
+ *    Copyright 2009-2018 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.
@@ -23,6 +23,7 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.function.Consumer;
 
 import org.apache.ibatis.binding.BindingException;
 import org.apache.ibatis.cursor.Cursor;
@@ -318,15 +319,35 @@ private boolean isCommitOrRollbackRequired(boolean force) {
   }
 
   private Object wrapCollection(final Object object) {
+    return wrapCollection(object, null);
+  }
+
+  /**
+   * Wrap a collection and array into {@link Map}.
+   *
+   * @param object a target parameter object
+   * @param mapConsumer consumer function for a map that wrapped collection and array. If
+   *        {@code object} is collection or array, this function will be called.
+   * @return If {@code object} is collection or array, return a map that wrapped collection and
+   *         array. Otherwise return a argument object.
+   * @since 3.5.0
+   */
+  public static Object wrapCollection(final Object object, final Consumer<Map<String, Object>> mapConsumer) {
     if (object instanceof Collection) {
       StrictMap<Object> map = new StrictMap<Object>();
+      if (mapConsumer != null) {
+        mapConsumer.accept(map);
+      }
       map.put("collection", object);
       if (object instanceof List) {
         map.put("list", object);
       }
       return map;
     } else if (object != null && object.getClass().isArray()) {
       StrictMap<Object> map = new StrictMap<Object>();
+      if (mapConsumer != null) {
+        mapConsumer.accept(map);
+      }
       map.put("array", object);
       return map;
     }

src/test/java/org/apache/ibatis/submitted/param_name_resolve/CreateDB.sql

@@ -0,0 +1,25 @@
+--
+--    Copyright 2009-2018 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.
+--
+
+drop table users if exists;
+
+create table users (
+  id int,
+  name varchar(20)
+);
+
+insert into users (id, name) values
+(1, 'User1'), (2, 'User2'), (3, 'User3');

src/test/java/org/apache/ibatis/submitted/param_name_resolve/Mapper.xml

@@ -0,0 +1,35 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+
+       Copyright 2009-2018 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.
+
+-->
+<!DOCTYPE mapper
+    PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
+    "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
+
+<mapper namespace="org.apache.ibatis.submitted.param_name_resolve.ParamNameResolveTest$Mapper">
+  <!-- when compiled with -parameters and useActualParamName enabled, -->
+  <!-- the first parameter should be accessed by its name 'ids',      -->
+  <!-- in addition with default name 'list' and 'collection'.         -->
+  <select id="getUserCount" resultType="Long">
+    select count(*)
+    from users u
+    where u.id in
+    <foreach item='item' index='index' collection='ids' open='(' separator=',' close=')'>
+      #{item}
+    </foreach>
+  </select>
+</mapper>

src/test/java/org/apache/ibatis/submitted/param_name_resolve/ParamNameResolveTest.java

@@ -0,0 +1,68 @@
+/**
+ *    Copyright 2009-2018 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.submitted.param_name_resolve;
+
+import org.apache.ibatis.io.Resources;
+import org.apache.ibatis.jdbc.ScriptRunner;
+import org.apache.ibatis.session.SqlSession;
+import org.apache.ibatis.session.SqlSessionFactory;
+import org.apache.ibatis.session.SqlSessionFactoryBuilder;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import java.io.Reader;
+import java.sql.Connection;
+import java.util.Arrays;
+import java.util.List;
+
+import static org.junit.Assert.assertEquals;
+
+public class ParamNameResolveTest {
+  private static SqlSessionFactory sqlSessionFactory;
+
+  @BeforeClass
+  public static void setUp() throws Exception {
+    // create an SqlSessionFactory
+    try (Reader reader = Resources
+        .getResourceAsReader("org/apache/ibatis/submitted/param_name_resolve/mybatis-config.xml")) {
+      sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
+    }
+
+    // populate in-memory database
+    try (SqlSession session = sqlSessionFactory.openSession();
+        Connection conn = session.getConnection();
+        Reader reader = Resources
+            .getResourceAsReader("org/apache/ibatis/submitted/param_name_resolve/CreateDB.sql")) {
+      ScriptRunner runner = new ScriptRunner(conn);
+      runner.setLogWriter(null);
+      runner.runScript(reader);
+    }
+  }
+
+  @Test
+  public void testSingleParameterWhenUseActualParamNameIsTrue() {
+    try (SqlSession sqlSession = sqlSessionFactory.openSession()) {
+      Mapper mapper = sqlSession.getMapper(Mapper.class);
+      long count = mapper.getUserCount(Arrays.asList(1, 2));
+      assertEquals(2, count);
+    }
+  }
+
+  interface Mapper {
+    Long getUserCount(List<Integer> ids);
+  }
+
+}

src/test/java/org/apache/ibatis/submitted/param_name_resolve/mybatis-config.xml

@@ -0,0 +1,40 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<!--
+
+       Copyright 2009-2018 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.
+
+-->
+<!DOCTYPE configuration
+    PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
+    "http://mybatis.org/dtd/mybatis-3-config.dtd">
+
+<configuration>
+
+  <environments default="development">
+    <environment id="development">
+      <transactionManager type="JDBC" />
+      <dataSource type="UNPOOLED">
+        <property name="driver" value="org.hsqldb.jdbcDriver"/>
+        <property name="url" value="jdbc:hsqldb:mem:param_name_resolve"/>
+        <property name="username" value="sa"/>
+      </dataSource>
+    </environment>
+  </environments>
+
+  <mappers>
+    <mapper resource="org/apache/ibatis/submitted/param_name_resolve/Mapper.xml"/>
+  </mappers>
+
+</configuration>