Mybatis源码解析之DefaultSqlSession#getMapper

Mybatis源码解析之SqlSession

上篇中我们探讨了SqlSession的构建流程,但是怎么去通过这个SqlSession去获取Mapper对象的?

XXXMapper mapper = sqlSession.getMapper(XXXMapper.class);

• 上一篇我们知道,这里返回是DefaultSqlSession
• 我们看下getMapper()这里面做了啥

  @Override
  public <T> T getMapper(Class<T> type) {
   
   
    return configuration.getMapper(type, this);
  }

 public <T> T getMapper(Class<T> type, SqlSession sqlSession) {
   
   
    return mapperRegistry.getMapper(type, sqlSession);
  }

我们知道Map<Class<?>, MapperProxyFactory<?>> knownMappers 这个是存放注册的Mapper接口的

 private final Map<Class<?>, MapperProxyFactory<?>> knownMappers = new HashMap<>();

  public MapperRegistry(Configuration config) {
   
   
    this.config = config;
  }

  @SuppressWarnings("unchecked")
  public <T> T