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在MyBatis中,如果要查看blob内容,可以通过以下步骤实现:
- 创建一个Mapper接口,定义一个方法来查询blob数据:
public interface BlobMapper { Blob selectBlobDataById(Integer id); }
- 创建对应的XML映射文件,编写查询语句:
<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd"> <mapper namespace="com.example.mapper.BlobMapper"> <select id="selectBlobDataById" resultType="java.sql.Blob"> SELECT blob_data FROM my_table WHERE id = #{id} </select> </mapper>
- 在代码中调用Mapper接口的方法获取blob数据:
public class Main { public static void main(String[] args) { SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(Resources.getResourceAsStream("mybatis-config.xml")); SqlSession sqlSession = sqlSessionFactory.openSession(); BlobMapper blobMapper = sqlSession.getMapper(BlobMapper.class); Blob blob = blobMapper.selectBlobDataById(1); //将Blob数据转换为字节数组 byte[] data = blob.getBytes(1, (int) blob.length()); //输出blob数据 System.out.println(Arrays.toString(data)); sqlSession.close(); } }
通过以上步骤,可以获取到blob数据并进行查看。需要注意的是,要根据具体的业务需求修改查询语句和数据处理逻辑。