title: How to get Map<String, String> as return type using mybatis annotations
body: <p>Using annotations in mybatis, can we have return type as normal map ?</p>
  
  <p>Basically, I want something like this</p>
  
  <pre><code>@Select("select a, b from tableA")
  public Map&lt;String, String&gt; getItems();
  </code></pre>
  
  <p>Where </p>
  
  <pre><code>mysql&gt; select * from tableA;
  +------+------+
  | a    | b    |
  +------+------+
  | 1    | a    |
  | 2    | b    |
  | 3    | c    |
  +------+------+
  
  mysql&gt; desc tableA;
  +-------+-------------+------+-----+---------+-------+
  | Field | Type        | Null | Key | Default | Extra |
  +-------+-------------+------+-----+---------+-------+
  | a     | varchar(10) | YES  |     | NULL    |       |
  | b     | varchar(10) | YES  |     | NULL    |       |
  +-------+-------------+------+-----+---------+-------+
  </code></pre>
  
  <p>Tried this</p>
  
  <pre><code>@Select("select a, b from tableA")
  @MapKey("a)
  public Map&lt;String, String&gt; getItems();
  </code></pre>
  
  <p>but it's giving below exception</p>
  
  <pre><code>### Cause: org.apache.ibatis.reflection.ReflectionException: There is no getter for property named 'a' in 'class java.lang.String'
  </code></pre>