图片的上传和预览(上传到oracle数据库)

注意:

1.数据库字段使用clob存储

2.实体类中使用byte数组存图片流

3.图片预览以流的形式输出

文件上传下载预览辅助类代码：

package com.yuanxin.app.appkmbgszh.util;import java.io.BufferedInputStream;import java.io.BufferedOutputStream;import java.io.File;import java.io.FileInputStream;import java.io.InputStream;import java.io.OutputStream;import java.net.URL;import java.net.URLConnection;import java.text.SimpleDateFormat;import java.util.ArrayList;import java.util.Date;import java.util.HashMap;import java.util.Iterator;import java.util.List;import java.util.Map;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import org.springframework.util.FileCopyUtils;import org.springframework.web.multipart.MultipartFile;import org.springframework.web.multipart.MultipartHttpServletRequest;import org.springframework.web.multipart.commons.CommonsMultipartResolver;public class FileUtil {    public static List<byte[]> upload(HttpServletRequest request) {        List<byte[]> ret = new ArrayList<byte[]>();        try {            // 将当前上下文初始化给 CommonsMutipartResolver （多部分解析器）            CommonsMultipartResolver multipartResolver = new CommonsMultipartResolver(request.getSession()                    .getServletContext());            // 检查form中是否有enctype="multipart/form-data"            if (multipartResolver.isMultipart(request)) {                // 将request变成多部分request                MultipartHttpServletRequest multiRequest = (MultipartHttpServletRequest) request;                // 获取multiRequest 中所有的文件名                Iterator iter = multiRequest.getFileNames();                InputStream is = null;                while (iter.hasNext()) {                    // 一次遍历所有文件                    MultipartFile file = multiRequest.getFile(iter.next().toString());                    if (file != null) {                        is = file.getInputStream();                        byte[] bytes = FileCopyUtils.copyToByteArray(is);                        ret.add(bytes);                        /*  SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMddHHssmm");                          Date date = new Date();                          String subfix = file.getOriginalFilename().substring(                                  file.getOriginalFilename().lastIndexOf(".") + 1, file.getOriginalFilename().length());                          String path1 = path + sdf.format(date) + "." + subfix;                          result.put("fileName", file.getOriginalFilename());                          result.put("path", path1);                          // 上传                          // 创建目录                          File fp = new File(path1);                          if (!fp.exists()) {                              // 目录不存在的情况下，创建目录。                              fp.mkdirs();                          }                          file.transferTo(fp);*/                    }                }            }        } catch (Exception e) {            // TODO: handle exception            e.printStackTrace();        }        return ret;    }    public static void downloadFile(HttpServletResponse response, String path, String fileName) {        try {            URL url = new URL(path);            URLConnection con = url.openConnection();            con.setConnectTimeout(5000);            con.setReadTimeout(5000);            //  File file = new File(path);            // 以流的形式下载文件。            InputStream is = con.getInputStream();            //InputStream is = url.openStream();             byte[] buffer = new byte[is.available()];            is.read(buffer);            is.close();            // 清空response            response.reset();            // 设置response的Header            response.addHeader("Content-Disposition", "attachment;filename="                    + new String(fileName.getBytes("gb2312"), "ISO8859-1"));            response.addHeader("Content-Length", "" + buffer.length);            OutputStream toClient = new BufferedOutputStream(response.getOutputStream());            response.setContentType("multipart/form-data");            toClient.write(buffer);            toClient.flush();            toClient.close();        } catch (Exception e) {            // TODO: handle exception            e.printStackTrace();        }    }    public static void showPhoto(HttpServletResponse response, byte[] photo) {        response.setContentType("image/*");        OutputStream toClient = null;        try {            toClient = response.getOutputStream();            toClient.write(photo);            toClient.close();        } catch (Exception e) {            e.printStackTrace();        }    }}

controller中控制代码：

//上传图片 @RequestMapping(value = "/headPortraitUpload", method = { RequestMethod.POST, RequestMethod.GET })    @ResponseBody    public Map<String, Object> headPortraitUpload(HttpServletRequest request, @Param("userCode") String userCode) {        LOGGER.info("有访问来自，IP: %s USER-AGENT: %s", request.getRemoteAddr(), request.getHeader("user-agent"));        LOGGER.info("userCode %s", userCode);        Map<String, Object> ret = new HashMap<String, Object>();        if (StringUtils.isBlank(userCode)) {            ret.put("success", false);            ret.put("msg", "userCode不能为空");        }        try {            List<byte[]> streams = FileUtil.upload(request);            if (streams != null && streams.size() > 0) {                User user = userService.getByCode(userCode).getData();                UserPhotoAO userPhotoAO = new UserPhotoAO();                userPhotoAO.setId(user.getId());                userPhotoAO.setUserCode(user.getCode());                userPhotoAO.setUserName(user.getName());                userPhotoAO.setPhoto(streams.get(0));                userPhotoService.saveOrUpdateUserPhotoAO(userPhotoAO, userCode);                ret.put("success", true);                ret.put("msg", "上传成功");            }        } catch (Exception e) {            e.printStackTrace();            ret.put("success", false);            ret.put("msg", "上传失败");        }        return ret;    }    /**     * 头像显示     * @param request     * @param response     * @param userCode     */    @RequestMapping(value = "/showPhoto")    public void showPhoto(HttpServletRequest request, HttpServletResponse response, @Param("userCode") String userCode) {        LOGGER.info("有访问来自，IP: %s USER-AGENT: %s", request.getRemoteAddr(), request.getHeader("user-agent"));        LOGGER.info("userCode %s", userCode);        UserPhoto userPhoto = userPhotoService.getUserPhotoAO(userCode);        if (userPhoto != null) {            FileUtil.showPhoto(response, userPhoto.getPhoto());        } else {            UserPhoto userPhoto1 = userPhotoService.getUserPhotoAO("admin");            FileUtil.showPhoto(response, userPhoto1.getPhoto());        }    }

实体字段：

  private byte[] photo;