js实现图片截取并上传到web服务器

package com.yc.utils; import java.io.IOException; import java.sql.SQLException; import java.util.Collection; import java.util.Date; import java.util.Enumeration; import java.util.HashMap; import java.util.Map; import java.util.Random; import javax.servlet.ServletException; import javax.servlet.jsp.PageContext; import com.jspsmart.upload.File; import com.jspsmart.upload.Files; import com.jspsmart.upload.Request; import com.jspsmart.upload.SmartUpload; import com.jspsmart.upload.SmartUploadException; /** * 文件上传的类 * @author navy */ public class UploadUtil { private static final String PATH="images"; //保存图片的路径 private static final String ALLOWED="gif,jpg,png,jpeg"; //允许上传的文件格式 private static final String DENIED="exe,bat,jsp,html,com"; //不可以上传的文件格式 private static final int TOTALMAXSIZE=20*1024*1024; //总文件大小 private static final int SINGLEFILESIZE=1024*1024; //单个文件大小 @SuppressWarnings({ "unchecked", "rawtypes" }) public Map<String,String> update(PageContext context) throws SmartUploadException, IOException, ServletException, SQLException{ Map<String,String> params=new HashMap<String,String>(); SmartUpload su=new SmartUpload(); su.initialize(context); //初始化 //设置参数 su.setMaxFileSize(SINGLEFILESIZE); su.setTotalMaxFileSize(TOTALMAXSIZE); su.setAllowedFilesList(ALLOWED); su.setDeniedFilesList(DENIED); su.setCharset("utf-8"); su.upload(); //开始上传 //获取请求中的信息 Request request=su.getRequest(); Enumeration et=request.getParameterNames(); String str; while(et.hasMoreElements()){ //请求中的普通表单元素信息 str=String.valueOf(et.nextElement()); params.put(str,request.getParameter(str)); } Files fls=su.getFiles(); String fileName; //文件名 String picPath=""; if(fls!=null && fls.getCount()>0){ //说明有文件 Collection<File> cols=fls.getCollection(); for(File fl:cols){ if( !fl.isMissing() ){ //判断上传的文件有没有丢失数据 fileName=PATH+"/"+new Date().getTime()+""+new Random().nextInt(100000)+"."+fl.getFileExt(); //获取扩展名 //将图片写入服务器 fl.saveAs(fileName,SmartUpload.SAVE_VIRTUAL); picPath+=fileName+","; } } picPath=picPath.substring(0,picPath.lastIndexOf(",")); params.put("photo",picPath); //往数据库存的图片路径信息 } return params; } }