JSP页面使用文件上传图片并且回传显示的注意事项

***要正常实现文件上传以下步骤应该全部考虑到：

*1.html中 表示文件上传控件

*2.form的enctype="multipart/form-data"

*3.在Servlet类前加上 @MultipartConfig             

*4.request.getPart()获得上传文件对象     //request.getParameter();

以下代码全是从我的代码了复制过来的，没有花太多的时间整理，先看一下效果图吧

  
enctype="multipart/form-data">
	
	

		

          	
上传照片
            

            	name="pic" /> 
            	
            
         
	
	

//下面代码是文件上传部分，功能主要是获取到上传图片的路劲和图片名称，然后上传图片，并把路径保存到数据库中

@WebServlet("/UploadImage")
@MultipartConfig	
public class UploadImage extends HttpServlet {
	private static final long serialVersionUID = 1L;
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		doPost(request, response);
	}

	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		System.out.println("---这里是上传个人图片的servlet----");
		
		Part part = request.getPart("pic");
		String file = part.getHeader("Content-Disposition");
		//得到文件的名字
		String fileName = file.substring(file.lastIndexOf("=")+2, file.length()-1);
		System.out.println(fileName);
		//获取部署的根目录
		String basePath = getServletContext().getRealPath("/");
		System.out.println(basePath);
		//将文件上传到部署的根目录下
		part.write(basePath+fileName);
		//以下代码是对应我的项目的，可以修改为对应自己项目的代码
		int id = Integer.parseInt(request.getParameter("updateId"));
		
		OperaterImpl operaterImpl = new OperaterImpl();
		OperaterEntity operaterEntity = operaterImpl.findById(id);
		operaterEntity.setpicPath(basePath+fileName);
		operaterImpl.update(operaterEntity);
		response.getWriter().write("");
	}

}

//以下是回显的servlet类，主要获取到图片的根目录，修改它就可以

@WebServlet("/ShowImageSer")
public class ShowImageSer extends HttpServlet {
	private static final long serialVersionUID = 1L;
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		
		//从前台获取图片的路劲（部署项目的根路径）此路劲必须包含到图片，
		//如D:\My\SOFTWORE\apache-tomcat-7.0.52\wtpwebapps\imas\111.gif
		String picPath = request.getParameter("picpath");
		//以该路劲创建一个新文件
		File file = new File(picPath);
		response.setCharacterEncoding("gb2312");
		response.setContentType("doc");
		response.setHeader("Content-Disposition", "attachment; filename=" + new String(file.getName().getBytes("gb2312"),"iso8859-1"));

		System.out.println(new String(file.getName().getBytes("gb2312"),"gb2312"));

		OutputStream output = null;
		FileInputStream fis = null;
		try{
			output = response.getOutputStream();
			fis = new FileInputStream(file);
	
			byte[] b = new byte[1024];
			int i = 0;
	
			while((i = fis.read(b))!=-1){
				output.write(b, 0, i);
			}
			output.write(b, 0, b.length);
	
			output.flush();
			response.flushBuffer();
		}
		catch(Exception e){
			System.out.println("Error!");
			e.printStackTrace();
		}
		finally{
			if(fis != null){
				fis.close();
				fis = null;
			}if(output != null){
				output.close();
				output = null;
			}
		}

	}

	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
	}

}

//这是显示图片的区域，使用img标签，在src里面访问到servlet类（ ShowImageSer），并且传递图片路劲参数过去

picpath=<%=operaterEntity.getpicPath() %>">