这里的案例使用了两种文件上传的组件、分别介绍

1、使用JSPSmartUpload完成上传

1 package test_servlet_package; 2  3 import java.io.File; 4 import java.io.IOException; 5 import java.util.Calendar; 6 import java.util.Random; 7 import javax.servlet.ServletException; 8 import javax.servlet.http.HttpServlet; 9 import javax.servlet.http.HttpServletRequest;10 import javax.servlet.http.HttpServletResponse;11 import com.jspsmart.upload.SmartUpload;12 13 public class test_servlet_SmartUpload extends HttpServlet {14 15     String tempPath = "D:\\test";16     String filePath = "D:\\filePath";17     @Override18     protected void doPost(HttpServletRequest request, HttpServletResponse response)19             throws ServletException, IOException {20         response.setCharacterEncoding("GBK");21         SmartUpload mySmartUpload = new SmartUpload();22         // 初始化23         mySmartUpload.initialize(getServletConfig(), request, response);24         long file_size_max = 4000000;25         String ext = "";26         try {27             mySmartUpload.setAllowedFilesList("jpg,gif,png");28             mySmartUpload.upload();// 上载文件29         } catch (Exception e) {30             response.getWriter().write("");31         }32         try {33             com.jspsmart.upload.File myFile = mySmartUpload.getFiles().getFile(0);34             if (!myFile.isMissing()) {35                 ext = myFile.getFileExt(); // 取得后缀名36                 int file_size = myFile.getSize(); // 取得文件的大小37                 String saveurl = "";38                 if (file_size < file_size_max) {39                     // 更改文件名，取得当前上传时间的毫秒数值40                     Calendar calendar = Calendar.getInstance();41                     String filename = String.valueOf(calendar.getTimeInMillis());42                     Random r = new Random();43                     String ram = String.valueOf(r.nextInt(1241241241));44                     filename = filename + ram;45                     filename = filename.substring(0, (filename.length() - ext.length() - 1));46                     //saveurl = this.getServletContext().getRealPath("/") + "/uploadFile/" + filename + "." + ext;47                     //System.out.println(saveurl);48                     File uploadFile2 = new File(filePath);49                     if(!uploadFile2.exists()){50                         uploadFile2.mkdirs();51                     }52                     myFile.saveAs(filePath+"/"+filename+"." + ext);53                 }54             }55             String name = mySmartUpload.getRequest().getParameter("name");56             request.setAttribute("name", "name");57             request.getSession().setAttribute("name", "name");58             request.getSession().getId();59             System.out.println(name);60         } catch (Exception e) {61             e.printStackTrace();62         }63         request.getRequestDispatcher("/uploadsuccess.jsp").forward(request, response);64     }65 }

2、使用commons-fileupload完成文件上传

1 package test_servlet_package; 2  3 import java.io.File; 4 import java.io.IOException; 5 import java.io.PrintWriter; 6 import java.util.Iterator; 7 import java.util.List; 8 import javax.servlet.ServletException; 9 import javax.servlet.http.HttpServlet;10 import javax.servlet.http.HttpServletRequest;11 import javax.servlet.http.HttpServletResponse;12 import org.apache.commons.fileupload.FileItem;13 import org.apache.commons.fileupload.disk.DiskFileItemFactory;14 import org.apache.commons.fileupload.servlet.ServletFileUpload;15 16 public class test_servlet extends HttpServlet {17 18     String tempPath = "D:\\test";19     String filePath = "D:\\filePath";20     @Override21     protected void doPost(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {22         res.setContentType("text/plain;charset=gbk");23         PrintWriter pw = res.getWriter();24         try {25             DiskFileItemFactory diskFactory = new DiskFileItemFactory();26             // threshold 极限、临界值，即硬盘缓存 1M27             diskFactory.setSizeThreshold(4 * 1024);28             // repository 贮藏室，即临时文件目录29             diskFactory.setRepository(new File(tempPath));30             ServletFileUpload upload = new ServletFileUpload(diskFactory);31             // 设置允许上传的最大文件大小 4M32             upload.setSizeMax(4 * 1024 * 1024);33             // 解析HTTP请求消息头34             List
     
       fileItems = upload.parseRequest(req);35             Iterator
      
        iter = fileItems.iterator();36             while (iter.hasNext()) {37                 FileItem item = (FileItem) iter.next();38                 if (item.isFormField()) {39                     System.out.println("处理表单内容 ...");40                     processFormField(item, pw);41                 } else {42                     System.out.println("处理上传的文件 ...");43                     processUploadFile(item, pw);44                 }45             }46             pw.close();47         } catch (Exception e) {48             System.out.println("使用 fileupload 包时发生异常 ...");49             e.printStackTrace();50         }51     }52 53     // 处理表单内容54     private void processFormField(FileItem item, PrintWriter pw) throws Exception {55         String name = item.getFieldName();56         String value = item.getString();57         pw.println(name + " : " + value + "\r\n");58     }59 60     // 处理上传的文件61     private void processUploadFile(FileItem item, PrintWriter pw) throws Exception {62         // 此时的文件名包含了完整的路径，得注意加工一下63         String filename = item.getName();64         System.out.println("完整的文件名：" + filename);65         int index = filename.lastIndexOf("\\");66         filename = filename.substring(index + 1, filename.length());67         long fileSize = item.getSize();68         if ("".equals(filename) && fileSize == 0) {69             System.out.println("文件名为空 ...");70             return;71         }72         File uploadFile = new File(filePath + "/" + filename);73         File uploadFile2 = new File(filePath);74         if(!uploadFile2.exists()){75             uploadFile2.mkdirs();76         }77         item.write(uploadFile);78         pw.println(filename + " 文件保存完毕 ...");79         pw.println("文件大小为 ：" + fileSize + "\r\n");80     }81 }
      
     

3、依赖的jar：

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