上传文件与表格照片

开发工具与关键技术：MyEclipse 10、java
作者：梁添荣
撰写时间：2019-6-08

有时项目需求，需要上传文件到数据库，查询出来的表格里有照片，此时需要准备两个jra包：comons-fileupload.jar和commons-io.jar
jsp from表单加属性enctype="multipart/form-data"

以下为上传文件：
	private void insertImg(HttpServletRequest request,
			HttpServletResponse response) {
//创建静态工厂
		FileItemFactory factory=new DiskFileItemFactory();
		ServletFileUpload fileUpload=new ServletFileUpload(factory);
		
		//upload.setFileSizeMax(1024*400);设置上传的文件
        //upload.setHeaderEncoding("gbk");
		
		List<FileItem> items=null;
		try {
			items=fileUpload.parseRequest(request);//执行一遍fileUpload.parseRequest(request)后该语句内容就会变成null
		} catch (FileUploadException e) {
			e.printStackTrace();
		}
		for (FileItem fileItem : items) {
			if(fileItem.isFormField()){
				String fileName=fileItem.getFieldName();
				String value=fileItem.getString();
				System.out.println(fileName+"的值是"+value);
			}else{
				try {
//					String folder = System.getProperty("user.dir");??
					//写入服务器
					byte[] b=new byte[10240*10];
					InputStream inputStream= fileItem.getInputStream();
					inputStream.read(b);//写进byte
					
					String path=this.getServletContext().getRealPath("/photo/P1112.PNG");
					File file=new File(path);
					FileOutputStream out=new FileOutputStream(file);
					out.write(b,0,b.length);
					out.flush();
					out.close();
					

					try {
						//图片写入数据库
						Class.forName(driver);
						Connection connection=DriverManager.getConnection(url,username,password);
						PreparedStatement ps=connection.prepareStatement(insert);
						ps.setString(1, "试试");
						
						//如果 inputStream.read(b);//写进b了
						ps.setBytes(2, b);//就用这个增进数据库
						
						//如果没有inputStream.read(b);  直接把字节流写进
//						ps.setBinaryStream(2, inputStream);
						ps.executeUpdate();
						connection.close();
						ps.close();
					} catch (ClassNotFoundException e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					}catch (SQLException e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					}
					
					
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
				
			}
		}
		
		
	}


//表格照片
	//查询照片
	private final ReentrantLock lock = new ReentrantLock();
	@Override
	public void photo(HttpServletRequest request, HttpServletResponse response,
			int id) {
		lock.lock();
		try {
			con=DBUtil.connection();
			ps=con.prepareStatement(photo);
			ps.setInt(1, id);
			rs=ps.executeQuery();
			while(rs.next()){
				InputStream in=rs.getBinaryStream("Photo");
				OutputStream ou=response.getOutputStream();
				byte[] b=new byte[1024*10];
				int n;
				while((n=in.read(b))!=-1){
					ou.write(b,0,n);
				}
				ou.flush();
				ou.close();
			}
		} catch (SQLException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}finally{
			DBUtil.colse(con, ps, rs);
			lock.unlock();
		}
	
	}
Jsp代码
  <c:forEach items="${drivers }" var="driver">
                               		<tr>
                               			<td style="display: none;">${driver.driverID }</td>
                               			<td>${driver.drivernumber }</td>
                               			<td>${driver.driverName }</td>
                               			<td>${driver.sex==false?"男":"女" }</td>
                               			<td>${driver.phone }</td>
                               			<td>${driver.iDno }</td>               			
                               			<td>${driver.quasidrivingtype }</td>
                               			<td><img src="servlet/Servlet?type=photo&id=${driver.driverID }" width="50px" height="60px" /></td>
                               		</tr>
                               
                               </c:forEach>