Flink Mybatis如何整合

Flink和MyBatis的整合可以通过自定义Source实现。下面是一个简单的示例：

1. 首先，创建一个MyBatis的Mapper接口和对应的Mapper XML文件，如下所示：

// UserMapper.java
public interface UserMapper {
    User getUserById(int id);
}

<!-- UserMapper.xml -->
<mapper namespace="com.example.UserMapper">
    <select id="getUserById" resultType="com.example.User">
        SELECT * FROM users WHERE id = #{id}
    </select>
</mapper>

2. 创建一个自定义的Source，用于从MyBatis中读取数据，并将数据发送到Flink的DataStream中：

public class MyBatisSourceFunction implements SourceFunction<User> {

    private boolean running = true;
    private SqlSessionFactory sqlSessionFactory;

    public MyBatisSourceFunction(SqlSessionFactory sqlSessionFactory) {
        this.sqlSessionFactory = sqlSessionFactory;
    }

    @Override
    public void run(SourceContext<User> ctx) throws Exception {
        try (SqlSession sqlSession = sqlSessionFactory.openSession()) {
            UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
            int userId = 1;
            while (running) {
                User user = userMapper.getUserById(userId);
                ctx.collect(user);
                userId++;
            }
        }
    }

    @Override
    public void cancel() {
        running = false;
    }
}

3. 在Flink程序中，创建一个ExecutionEnvironment，并使用自定义的Source作为数据源：

public static void main(String[] args) throws Exception {
    // 创建MyBatis的SqlSessionFactory
    SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(Resources.getResourceAsStream("mybatis-config.xml"));

    // 创建ExecutionEnvironment
    final StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();

    // 添加自定义的Source作为数据源
    DataStream<User> stream = env.addSource(new MyBatisSourceFunction(sqlSessionFactory));

    // 打印数据流
    stream.print();

    // 执行Flink程序
    env.execute("MyBatisSourceFunction Example");
}

通过以上步骤，就可以实现Flink和MyBatis的整合。当然，实际应用中可能需要根据具体需求进行定制和调整。