根据 Mapper 接口、其方法、方法上的注解，生成 mappedStatementId 与 MapperStatement，注册到 configuration 对象中
根据 Mapper 接口方法查到并调用对应的 MappedStatement，执行 SQL
流程与 Mapper 接口与 xml 绑定类似。
分析
解析生成注册 MapperStatement 的代码入口在 MapperRegistry addMapper 方法
//使用 MapperProxyFactory 包装 Mapper 接口 Class 对象
knownMappers.put(type, new MapperProxyFactory<>(type));
//解析 Mapper 接口方法上的注解，生成对应的 MapperStatement
MapperAnnotationBuilder parser = new MapperAnnotationBuilder(config, type);
parser.parse();
获取 Mapper 接口的动态代理对象的代码入口在 MapperRegistry getMapper 方法
public <T> T getMapper(Class<T> type, SqlSession sqlSession) {
final MapperProxyFactory<T> mapperProxyFactory = (MapperProxyFactory<T>) knownMappers.get(type);
if (mapperProxyFactory == null) {
throw new BindingException("Type " + type + " is not known to the MapperRegistry.");
}
try {
return mapperProxyFactory.newInstance(sqlSession);
} catch (Exception e) {
throw new BindingException("Error getting mapper instance. Cause: " + e, e);
}
}