利用java代码将mysql的blob转化为String类型

可以使用以下代码把 MySQL 的 blob 转成字符串：

Connection conn = null;
PreparedStatement ps = null;
ResultSet rs = null;
try {
    conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/test", "root", "password");
    ps = conn.prepareStatement("SELECT content FROM mytable WHERE id = ?");
    ps.setInt(1, id);
    rs = ps.executeQuery();
    if (rs.next()) {
        Blob blob = rs.getBlob("content");
        byte[] bytes = blob.getBytes(1, (int) blob.length());
        String content = new String(bytes, "UTF-8");
        System.out.println(content);
    }
} catch (SQLException e) {
    e.printStackTrace();
} finally {
    try {
        if (rs != null) rs.close();
        if (ps != null) ps.close();
        if (conn != null) conn.close();
    } catch (SQLException e) {
        e.printStackTrace();
    }
}