Spring MVC上传图片,Java二进制图片写入数据库,生成略缩图

时间:2023-02-10 21:44:13

背景描述:最近做到一个项目,有个商品登记功能。登记的信息包括:基本信息若干(文字信息);图片信息,要求将图片保存到数据表中的image字段(sql server 数据库)

步骤:1.将图片上传到服务器的一个磁盘目录下。

        2.将刚才上传好的图片写入数据库image字段。

一、上传图片:使用的是spring mvc 对上传的支持。

jsp 页面

<form name="uploadForm" id="uploadForm" method="post" action="${base}goods/doUploadFile" 
            enctype="multipart/form-data">
            <input type="file" name="image" /><br/>
            <input type="submit" value="上传" class="btn4" />
        </form>

spring_mvc.xml配置

<bean
id="multipartResolver"
class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
</bean>

Controller:

@RequestMapping("/doUploadFile")
    public ModelAndView doUploadFile(HttpServletRequest request,
            HttpServletResponse response, HttpSession session)
            throws Exception, IOException {

        // 转型为MultipartHttpRequest:
        MultipartHttpServletRequest multipartRequest = (MultipartHttpServletRequest) request;
        // 获得文件:
        MultipartFile file = multipartRequest.getFile("image");
        // 获得文件名:
        String filename = file.getOriginalFilename();

        InputStream input = file.getInputStream();
        // String path = "D:/goodsImages";下边这个path是写在配置文件里边的,方便修改,这个方法很长但或得的结果就是路劲D:/goodsImages
        String path = ConfigConstants.getInstance()
                .get("goods.uploadImage.dir");
        File savePath = new File(path);
        if (!savePath.exists()) { // 文件夹
            savePath.mkdir();
        }
        SaveFileFromInputStream(input, savePath.toString(), filename);

        String result = "上传成功!";
        ModelAndView modelAndView = new ModelAndView("goods/uploadSuccess");
        modelAndView.addObject("result", result);
        modelAndView.addObject("filename", filename);

        return modelAndView;
    }

如此上传就搞定了。

上传文件补充,另一个方法

  1.项目中导入  jar 包 cos.jar

      2.表单: enctype="multipart/form-data"

      3.处理方法:主要用到  MultipartRequest 类 ,详细情况查看:http://www.servlets.com/cos/javadoc/com/oreilly/servlet/MultipartRequest.html

    @RequestMapping(value = "/uploadImage.do")
    public String uploadImage(HttpServletRequest request) throws Exception {
        MultipartRequest mr = null;
        int maxPostSize = 1 * 100 * 1024;
        mr=new MultipartRequest(request,"E:\\goodsImages",maxPostSize,"GBK");
        return null;
    }

 

二、生成略缩图。

public void createIcon() {
        try {
            File fiBig = new File("D:/log/tickit.png"); // 大图文件
            File foSmall = new File("D:/log/tickitIcon.png"); // 将要转换出的小图文件

            AffineTransform transform = new AffineTransform();
            //读取图片
            BufferedImage bis = ImageIO.read(fiBig);
            //获得图片原来的高宽
            int w = bis.getWidth();
            int h = bis.getHeight();
            
            double scale = (double) w / h;
       //等比例缩放 
            int nowWidth = 120;
            int nowHeight = (nowWidth * h) / w;
            if (nowHeight > 120) {
                nowHeight = 120;
                nowWidth = (nowHeight * w) / h;
            }

            double sx = (double) nowWidth / w;
            double sy = (double) nowHeight / h;

            transform.setToScale(sx, sy);

            AffineTransformOp ato = new AffineTransformOp(transform, null);
            BufferedImage bid = new BufferedImage(nowWidth, nowHeight,
                    BufferedImage.TYPE_3BYTE_BGR);
            ato.filter(bis, bid);
            
            ImageIO.write(bid, "png", foSmall);
        } catch (Exception e) {
            e.printStackTrace();
        }

    }

三、图片写入数据库。

1.图片实体类的 图片字段(picture) 用  byte[]类型

@Entity
@Table(name = "spaq_pic")
public class GoodsPic {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "pic_id")
    private Long picId;

    @Column(name = "pic_name")
    private String picName;

    @Column(name = "pic_descr")
    private String picDescr;

    @Column(name = "picture")
    private byte[] picture;//
         
   //省略其他字段及get,set方法
}        

2.代码,读取本地图片储存在byte[]中,付给实体类的picture字段,调用 hibernate的save方法保存

/**
     * hibernate保存图片到数据表
     */
    @Transactional(readOnly = false)
    public void hibsaveImage(GoodsPic gp, String path) {//GoodsPic为图片实体类,path为图片所在磁盘的路径

        try {
            InputStream in = null;
            in = new FileInputStream(path);
            byte[] b = new byte[in.available()];
            in.read(b);
            in.close();
            gp.setPicture(b);

            myDao.save(gp);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }