数据库取到blob对象转换成String对象

weixin_45305727

已于 2022-09-30 09:39:58 修改

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文章标签：数据库 sql mybatis java

于 2022-09-30 09:38:23 首次发布

本文链接：https://blog.youkuaiyun.com/weixin_45305727/article/details/127117884

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1.用Map查询单条数据。

<select id="" resultType="java.util.Map">
    sql语句
</select>

2.将数据强转为blob对象

BLOB blob= (BLOB) map.get("数据列名");

3.将blob对象转成byte[]

private byte[] blobToBytes(BLOB blob) {
    BufferedInputStream is = null;
    try {
        is = new BufferedInputStream(blob.getBinaryStream());
        byte[] bytes = new byte[(int) blob.length()];
        int len = bytes.length;
        int offset = 0;
        int read = 0;

        while (offset < len && (read = is.read(bytes, offset, len - offset)) >= 0) {
            offset += read;
        }
        return bytes;
    } catch (Exception e) {
        return null;
    } finally {
        try {
            is.close();
            is = null;
        } catch (IOException e) {
            return null;
        }
    }
}

4.将byte[] 对象转成String

byte[] result = blobToBytes(blob);
String swe=new String(result);