檔案上傳是網站非常常用的功能，直接使用Servlet獲取上傳檔案還得解析請求引數，比較麻煩，所以一般選擇採用

apache的開源工具，common-fileupload.這個jar包可以再apache官網上面找到，也可以在struts的lib資料夾下面找到，

struts上傳的功能就是基於這個實現的。

common-fileupload是依賴於common-io這個包的，所以還需要下載這個包。然後匯入到你的專案路徑下面。

使用程式碼如下

package oop.hg.ytu.servlet;import java.io.File;import java.io.IOException;import java.io.InputStream;import
 
 java.util.List;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import oop.hu.ytu.dao.UploadDomain;import org.apache.commons.fileupload.FileItem;import org.apache.commons.fileupload.disk.DiskFileItemFactory;import
 
 org.apache.commons.fileupload.servlet.ServletFileUpload;public class Upload extends HttpServlet { /**  * 處理使用者上傳請求  */ private static final long serialVersionUID = 1L; public void doGet(HttpServletRequest request, HttpServletResponse response)   throws ServletException, IOException { // String describe = request.getParameter("describe");
 
  DiskFileItemFactory factory = new DiskFileItemFactory();  @SuppressWarnings("deprecation")  String path = request.getRealPath("/upload");//設定磁碟緩衝路徑   factory.setRepository(new File(path));  factory.setSizeThreshold(1024*1024);//設定建立緩衝大小    ServletFileUpload upload = new ServletFileUpload(factory);  upload.setSizeMax(-1);//設定上傳檔案限制大小,-1無上限  try {   @SuppressWarnings("unchecked")   List<FileItem> list = upload.parseRequest(request);   String va = null;   for(FileItem item : list){  //  String name = item.getFieldName();    if(item.isFormField()){//判斷是否是檔案流          va = item.getString("UTF-8");    // System.out.println(name+"="+va);   ///  request.setAttribute(name, value);    }else{     String value = item.getName();//會將完整路徑名傳過來     int start = value.lastIndexOf("\\");     String fileName = value.substring(start+1);   //  request.setAttribute(name, fileName);     InputStream in = item.getInputStream();     UploadDomain dao = new UploadDomain();     //item.write(new File(realPath,fileName));     int index = fileName.lastIndexOf(".");     String realFileName = fileName.substring(0,index);     String type = fileName.substring(index+1);     dao.insert(in, realFileName,type,va);//放入到資料庫中         }   }  } catch (Exception e) {      e.printStackTrace();  } } public void doPost(HttpServletRequest request, HttpServletResponse response)   throws ServletException, IOException {  doGet(request, response); }}

程式碼如下

package oop.hu.ytu.dao;import java.io.InputStream;import java.sql.Connection;import java.sql.PreparedStatement;import java.sql.ResultSet;import oop.hg.ytu.utils.JdbcUtils;/** * 提供檔案上傳支援 * @author Administrator * */public class UploadDomain { /**  * 將上傳的檔案流放入到資料庫中  */ public void insert(InputStream in, String fileName, String type,String describe) throws Exception{//向資料庫中寫入圖片          Connection conn = null;          PreparedStatement ps = null;          ResultSet rs = null;          System.out.println(describe);        try {              // 2.建立連線              conn = JdbcUtils.getConnection();            // 3.建立語句              String sql = "insert into fileupload(file,filename,type,des) values (?,?,?,?)";              ps = conn.prepareStatement(sql);              ps.setBlob(1, in);            ps.setString(2, fileName);            ps.setString(3, type);            ps.setString(4, describe);            // 4.執行語句              ps.executeUpdate();                in.close();                      } finally {              JdbcUtils.free(rs, ps, conn);          }      }  }

[mysqld]max_allowed_packet=64M

突，出現無法插入資訊現象，以後一定要注意.