java+Jcrop实现上传即时显示图片并裁剪

package com.jiong.uploadify; import java.io.File; import java.io.IOException; import java.io.PrintWriter; import java.util.Iterator; import java.util.List; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.fileupload.FileItem; import org.apache.commons.fileupload.FileUploadException; import org.apache.commons.fileupload.disk.DiskFileItemFactory; import org.apache.commons.fileupload.servlet.ServletFileUpload; import com.jenmin.dao.UserDao; public class UploadServlet extends HttpServlet { UserDao ud = UserDao.getInstance(); public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { this.doPost(request, response); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("UTF-8"); response.setContentType("text/html;charset=UTF-8"); PrintWriter out = response.getWriter(); String userid = request.getParameter("userid"); if (userid != null && !userid.equals("")) { String savePath = generateDir(); processUpload(request, response, savePath, Integer.parseInt(userid)); } } /* * 上传处理方法 */ public void processUpload(HttpServletRequest request, HttpServletResponse response, String savePath, int userid) { DiskFileItemFactory factory = new DiskFileItemFactory(); // 缓存大小丿12KB factory.setSizeThreshold(524288); // 临时文件夿 factory.setRepository(new File(savePath + "/temp")); // 初妾化上传控仿 ServletFileUpload upload = new ServletFileUpload(factory); // 文件大小朿ħ3MB upload.setFileSizeMax(3145728); upload.setHeaderEncoding("UTF-8"); List fileList = null; try { fileList = upload.parseRequest(request); } catch (FileUploadException e) { e.printStackTrace(); } Iterator<FileItem> it = fileList.iterator(); String name = ""; String filename = ""; while (it.hasNext()) { FileItem item = it.next(); if (!item.isFormField()) { name = item.getName(); if (name != null && !name.trim().equals("")) { filename = generateFileName(name); File file = new File(savePath + "/" + filename); System.out.println("%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%="+savePath); try { item.write(file); String imgstr = this.getServletContext() .getContextPath(); imgstr = imgstr + "/upload/" + filename; ud.updateImgBySql(imgstr, userid); response.getWriter().write("http://localhost:8080"+imgstr); } catch (Exception e) { e.printStackTrace(); } } } } } /* * 初妾化文件存储路徿 */ private String generateDir() { String pathString = getServletConfig().getServletContext().getRealPath( "/upload"); String tempString = getServletConfig().getServletContext().getRealPath( "/upload/temp"); File dirPath = new File(pathString); File dirTemp = new File(tempString); if (!dirPath.exists()) { dirPath.mkdirs(); } if (!dirTemp.exists()) { dirTemp.mkdirs(); } return pathString; } /* * 生成文件吿 */ private String generateFileName(String name) { long currentTime = System.currentTimeMillis(); int i = (int) (Math.random() * 1000D + 1.0D); long result = currentTime + i; String filename = String.valueOf(result) + getFileExt(name); return filename; } /* * 获取文件格式 */ private String getFileExt(String name) { int pos = name.lastIndexOf("."); if (pos > 0) { return name.substring(pos); } else { return name; } } }