例子比较 简单，服务端为Java Web Servlet，doPost方法中接收图片并保存，然后将保存的图片名返回给客户端，关键代码：
@SuppressWarnings("deprecation")public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {request.setCharacterEncoding("utf-8"); //设置编码//获得磁盘文件条目工厂DiskFileItemFactory factory = new DiskFileItemFactory();//获取文件需要上传到的路径String path = request.getRealPath("/upload");File file=new File(path);if(!file.exists()){file.mkdirs();}factory.setRepository(new File(path));//设置 缓存的大小factory.setSizeThreshold(1024*1024) ;//文件上传处理ServletFileUpload upload = new ServletFileUpload(factory);try {//可以上传多个文件List<FileItem> list = (List<FileItem>)upload.parseRequest(request);for(FileItem item : list){//获取属性名字String name = item.getFieldName();//如果获取的 表单信息是普通的 文本 信息if(item.isFormField()){//获取用户具体输入的字符串,因为表单提交过来的是 字符串类型的String value = item.getString() ;request.setAttribute(name, value);}else{//获取路径名String value = item.getName() ;//索引到最后一个反斜杠int start = value.lastIndexOf("\\");//截取 上传文件的 字符串名字，，加1是 去掉反斜杠，String filename = value.substring(start+1);request.setAttribute(name, filename);//写到磁盘上item.write( new File(path,filename) );//第三方提供的System.out.println("上传成功："+filename);response.getWriter().print(filename);//将路径返回给客户端}}} catch (Exception e) {System.out.println("上传失败");response.getWriter().print("上传失败："+e.getMessage());}}该方法同样适用于web端即网页图片上传，不是本文重点，不在讲解。
客户端关键代码：
/** * 文件上传 * * @param urlStr 接口路径 * @param filePath 本地图片路径 * @return */public static String formUpload(String urlStr, String filePath) {String rsp = "";HttpURLConnection conn = null;String BOUNDARY = "|"; // request头和上传文件内容分隔符try {URL url = new URL(urlStr);conn = (HttpURLConnection) url.openConnection();conn.setConnectTimeout(5000);conn.setReadTimeout(30000);conn.setDoOutput(true);conn.setDoInput(true);conn.setUseCaches(false);conn.setRequestMethod("POST");conn.setRequestProperty("Connection", "Keep-Alive");conn.setRequestProperty("User-Agent","Mozilla/5.0 (Windows; U; Windows NT 6.1; zh-CN; rv:1.9.2.6)");conn.setRequestProperty("Content-Type","multipart/form-data; boundary=" + BOUNDARY);OutputStream out = new DataOutputStream(conn.getOutputStream());File file = new File(filePath);String filename = file.getName();String contentType = "";if (filename.endsWith(".png")) {contentType = "image/png";}if (filename.endsWith(".jpg")) {contentType = "image/jpg";}if (filename.endsWith(".gif")) {contentType = "image/gif";}if (filename.endsWith(".bmp")) {contentType = "image/bmp";}if (contentType == null || contentType.equals("")) {contentType = "application/octet-stream";}StringBuffer strBuf = new StringBuffer();strBuf.append("\r\n").append("–").append(BOUNDARY).append("\r\n");strBuf.append("Content-Disposition: form-data; name=\&;" + filePath+ "\&;; filename=\&;" + filename + "\&;\r\n");strBuf.append("Content-Type:" + contentType + "\r\n\r\n");out.write(strBuf.toString().getBytes());DataInputStream in = new DataInputStream(new FileInputStream(file));int bytes = 0;byte[] bufferOut = new byte[1024];while ((bytes = in.read(bufferOut)) != -1) {out.write(bufferOut, 0, bytes);}in.close();byte[] endData = ("\r\n–" + BOUNDARY + "–\r\n").getBytes();out.write(endData);out.flush();out.close();// 读取返回数据StringBuffer buffer = new StringBuffer();BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream(), "utf-8"));String line = null;while ((line = reader.readLine()) != null) {buffer.append(line).append("\n");}rsp = buffer.toString();reader.close();reader = null;} catch (Exception e) {e.printStackTrace();} finally {if (conn != null) {conn.disconnect();conn = null;}}return rsp;}服务端图例：
客户端图例：
注意：测试的时候，请在客户端书写完整的本机局域网IP地址：
没有什么可留恋，只有抑制不住的梦想，没有什么可凭仗，
