mybatis 读取blob数据

mybatis读取blob数据过程：

1、从数据库中读出blob数据类型，用pojo中的byte[]接收。

2、把文件保存成文件（或者变成base64也行）。

Customer.java

public class Customer {    private String cuscode;    private byte[] qrcode;    public String getCuscode() {        return cuscode;    }    public void setCuscode(String cuscode) {        this.cuscode = cuscode;    }    public byte[] getQrcode() {        return qrcode;    }    public void setQrcode(byte[] qrcode) {        this.qrcode = qrcode;    }}

springmvc中的请求

@RequestMapping(value = "/web/showerweima")    @ResponseBody    public String showerweima() {        Map<String,Object> params = new HashMap<String, Object>();        params.put("cuscode","vvcc");        Map<String,Object> resMap = memberManagementServices.getQrcode(params);        byte[] buffer = (byte[])resMap.get("imgstr");        File file = new File("d:/temp/cccc.png");        FileOutputStream fos = null;        try {            fos = new FileOutputStream(file);        } catch (FileNotFoundException e) {            e.printStackTrace();        }        BufferedOutputStream bos = new BufferedOutputStream(fos);        try {            bos.write(buffer);        } catch (IOException e) {            e.printStackTrace();        }        return "123";    }

对应的dao层

Customer getQrcode(Map<String, Object> params);

xml文件中的内容：

<select id="getQrcode" parameterType="map" resultType="com.xueyou.model.Customer">        SELECT  * from t_customer where cuscode = #{cuscode}    </select>

这样能够把图片保存成文件。