选修课程选课系统的设计与开发代码

package servlet; import java.io.File; import java.io.IOException; import java.io.PrintWriter; import java.util.Iterator; import java.util.List; import java.sql.*; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; import org.apache.commons.fileupload.FileItem; import org.apache.commons.fileupload.FileUploadException; import org.apache.commons.fileupload.FileUploadBase.SizeLimitExceededException; import org.apache.commons.fileupload.disk.DiskFileItemFactory; import org.apache.commons.fileupload.servlet.ServletFileUpload; public class FileUploadServlet extends HttpServlet { public FileUploadServlet() { super(); } public void destroy() { super.destroy(); // Just puts "destroy" string in log // Put your code here } public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request, response); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { HttpSession session=request.getSession(false); if(session==null||session.getAttribute("type")==null) {response.sendRedirect("/myweb/index.jsp");return;} else{ request.setCharacterEncoding("gb2312"); String type=(String)session.getAttribute("type"); final long MAX_SIZE = 8 * 1024 * 1024;// 设置上传文件最大为 3M // 允许上传的文件格式的列表 final String[] allowedExt = new String[] { "jpg", "jpeg", "gif", "txt", "doc", "docx", "mp3", "wma", "m4a" }; response.setContentType("text/html"); // 设置字符编码为UTF-8, 这样支持汉字显示 response.setCharacterEncoding("UTF-8"); String couid=null; // 实例化一个硬盘文件工厂,用来配置上传组件ServletFileUpload DiskFileItemFactory dfif = new DiskFileItemFactory(); dfif.setSizeThreshold(4096);// 设置上传文件时用于临时存放文件的内存大小,这里是4K.多于的部分将临时存在硬盘 dfif.setRepository(new File(request.getRealPath("/") + "UploadTemp"));// 设置存放临时文件的目录,web根目录下的ImagesUploadTemp目录 // 用以上工厂实例化上传组件 ServletFileUpload sfu = new ServletFileUpload(dfif); // 设置最大上传尺寸 sfu.setHeaderEncoding("gb2312"); sfu.setSizeMax(MAX_SIZE); PrintWriter out = response.getWriter(); // 从request得到 所有 上传域的列表 List fileList = null; try { fileList = sfu.parseRequest(request); } catch (FileUploadException e) {// 处理文件尺寸过大异常 if (e instanceof SizeLimitExceededException) { out.println("文件尺寸超过规定大小:" + MAX_SIZE + "字节<p />"); if(type.equals("teacher")) out.println("<a href=\"/myweb/teacher/t_file.jsp\" target=\"_top\">返回</a>"); else { out.println("<a href='javascript:self.close()'>确 定</a>"); } return; } e.printStackTrace(); } // 没有文件上传 if (fileList == null || fileList.size() == 0) { out.println("请选择上传文件<p />"); if(type.equals("teacher")) out.println("<a href=\"/myweb/teacher/t_file.jsp\" target=\"_top\">返回</a>"); else { out.println("<a href='javascript:self.close()'>确 定</a>"); } return; } // 得到所有上传的文件 Iterator fileItr = fileList.iterator(); // 循环处理所有文件 while (fileItr.hasNext()) { FileItem fileItem = null; String path = null; long size = 0; // 得到当前文件 fileItem = (FileItem) fileItr.next(); // 忽略简单form字段而不是上传域的文件域(<input type="text" />等) if ( fileItem!=null&&fileItem.isFormField()){ if(fileItem.getFieldName().equals("couid")){ couid=fileItem.getString(); } } else if(fileItem!=null&&!fileItem.isFormField()){ // 得到文件的完整路径 path = fileItem.getName(); // 得到文件的大小 size = fileItem.getSize(); if ("".equals(path) || size == 0) { out.println("请选择上传文件<p />"); if(type.equals("teacher")) out.println("<a href=\"/myweb/teacher/t_file.jsp\" target=\"_top\">返回</a>"); else { out.println("<a href='javascript:self.close()'>确 定</a>"); } return; } // 得到去除路径的文件名 String t_name = path.substring(path.lastIndexOf("\\") + 1); // 得到文件的扩展名(无扩展名时将得到全名) String t_ext = t_name.substring(t_name.lastIndexOf(".") + 1); // 拒绝接受规定文件格式之外的文件类型 /*int allowFlag = 0; int allowedExtCount = allowedExt.length; for (; allowFlag < allowedExtCount; allowFlag++) { if (allowedExt[allowFlag].equals(t_ext)) break; } if (allowFlag == allowedExtCount) { out.println("请上传以下类型的文件<p />"); for (allowFlag = 0; allowFlag < allowedExtCount; allowFlag++) out.println("*." + allowedExt[allowFlag] + "&nbsp;&nbsp;&nbsp;"); out.println("<p /><a href=\"upload.html\" target=\"_top\">返回</a>"); return; } */ //long now = System.currentTimeMillis(); // 根据系统时间生成上传后保存的文件名 // String prefix = String.valueOf(now); // 保存的最终文件完整路径,保存在web根目录下的Uploaded目录下 //教师上传文件的处理 beans.Jdbc db=new beans.Jdbc(); if(type.equals("teacher")){ String u_name = request.getRealPath("/") + "Uploaded/" + t_name; try { // 保存文件 fileItem.write(new File(u_name)); response.sendRedirect("/myweb/teacher/t_file.jsp"); } catch (Exception e) { e.printStackTrace(); } String teaid=(String)session.getAttribute("id"); String mysqlt="insert into file(teaid,couid,filename) values('"+teaid+"','"+couid+"','"+t_name+"')"; db.update(mysqlt); db.close(); } //学生上传文件处理 else if(type.equals("student")){ String stuid=(String)session.getAttribute("id"); String sfname=couid+stuid+"."+t_ext; String workname=request.getRealPath("/")+"Uploaded/"+sfname; try { // 保存文件 fileItem.write(new File(workname)); out.println("<div style='text-align:center;margin:20px;'>作业提交成功!</div>"); out.println("<div style='text-align:center;'><a href='javascript:self.close()'>关闭</a></div>"); } catch (Exception e) { e.printStackTrace(); } String mysqls="update cs set work='"+sfname+"' where stuid='"+stuid+"' and couid='"+couid+"';"; db.update(mysqls); db.close(); } }}}} public void init() throws ServletException { // Put your code here } }