這個問題有些複雜，因爲在上傳文件需要在標籤中加入enctype=”multipart/form-data”這個屬性，表單中enctype=”multipart/form-data”的意思，是設置表單的MIME編碼。默認情況，這個編碼格式是application/x-www-form-urlencoded，不能用於文件上傳；只有使用了multipart/form-data，才能完整的傳遞文件數據，進行下面的操作.
enctype=”multipart/form-data”是上傳二進制數據; form裏面的input的值以2進制的方式傳過去。 form裏面的input的值以2進制的方式傳過去，所以request就得不到值了。
所以這裏我們就需要用到第三方包了。
我這個裏用的是commons-fileupload-1.2.jar和commons-io-1.2.jar這兩個類庫。
然後直接進入代碼吧。
還是老樣子，先列出需要的類和方法。
一個JSP頁面，一個model，一個servlet
jsp:upload.jsp,
model:GoodsBeanBO.java
servlet:UploadServlet.java
正式代碼：
upload.jsp
<%@ page contentType="text/html;charset=gb2312" language="java"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>上傳</title>
<META http-equiv=Content-Type content="text/html;charset=gb2312">
</head>
<body>
<form action="UploadSevlet" enctype="multipart/form-data" method="post">
圖片：<input type="file" id="file1" name="file1"><br/>
名稱：<input type="text" id="Name" name="Name"><br/>
簡介：<input type="text" id="Intro" name="Intro"><br/>
價格：<input type="text" id="Price" name="Price"><br/>
數量：<input type="text" id="Num" name="Num"> 可以不填<br/>
產地：<input type="text" id="Publisher" name="Publisher"><br/>
標籤：<input type="text" id="Type" name="Type"><br/>
<input type="submit" value="上傳">
</form>
</body>
</html>
model.java
這個是實現方法的類，裏面有各種各樣的方法， 我這裏只列出這個模塊用到的方法。
public GoodsBean savaGoods(GoodsBean gb) {
Connection ct = ConnDB.getConn();
String sql = "INSERT INTO goods(goodsName,goodsIntro,goodsPrice,goodsNum,publisher,photo,type) values(?,?,?,?,?,?,?)";
try {
PreparedStatement ps = ct.prepareStatement(sql);
ps.setString(1, gb.getGoodsName());
ps.setString(2, gb.getGoodsIntro());
ps.setString(3, gb.getGoodsPrice());
ps.setString(4, gb.getGoodsNum());
ps.setString(5, gb.getPublisher());
ps.setString(6, gb.getPhoto());
ps.setString(7, gb.getType());
ps.executeUpdate();
ps.close();
} catch (Exception e) {
e.printStackTrace();
}finally{
this.close();
}
return gb;
}最後一個是servlet控制器最重要的步驟
UploadServlet.java
package com.sp.servlet;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Iterator;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
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.sp.model.GoodsBean;
import com.sp.model.GoodsBeanBO;
/**
* Servlet implementation class UploadSevlet
*/
@WebServlet("/UploadSevlet")
public class UploadSevlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public UploadSevlet() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html");
response.setCharacterEncoding("gb2312");
PrintWriter out = response.getWriter();
DiskFileItemFactory factory = new DiskFileItemFactory();
factory.setSizeThreshold(1024 * 1024);//1M
ServletFileUpload upload = new ServletFileUpload(factory);
upload.setFileSizeMax(1024 * 1024 * 50);//50M
String fieldName= null;
FileItem item=null;
String values = null;
try {
GoodsBeanBO gbb = new GoodsBeanBO();
GoodsBean gb = new GoodsBean();
Iterator<FileItem> iterator = upload.parseRequest(request).iterator();
while(iterator.hasNext()){
item = iterator.next();
if(item.isFormField()){
out.println(item.getFieldName()+"="+item.getString("gb2312")+"<br>");
fieldName = item.getFieldName();//得到表單中name的值
values = item.getString("gb2312");//得到表單中value的值
/**
* 根據表單控件名得到value的值並且插入到GoodsBean中
*/
if(fieldName.equals("Name")) {
gb.setGoodsName(new String(values));}
else if(fieldName.equals("Intro")) {
gb.setGoodsIntro(new String(values));}
else if(fieldName.equals("Price")) {
gb.setGoodsPrice(new String(values));}
else if(fieldName.equals("Num")) {
gb.setGoodsNum(new String(values));}
else if(fieldName.equals("Publisher")) {
gb.setPublisher(new String(values));}
else if(fieldName.equals("Type")) {
gb.setType(new String(values));}
} else {
//上傳路徑
String contextRealPath = "D:/Program Files/Android/workspace_Web/Catering/WebContent/images/menu/";
String fileName = item.getName();//得到文件名
int xieGangIndex = fileName.lastIndexOf("\\") + 1;
fileName = fileName.substring(xieGangIndex);
System.out.println(contextRealPath);
System.out.println(fileName);
gb.setPhoto(fileName);//把photo插入GoodsBean中
FileOutputStream outputStream = new FileOutputStream(contextRealPath + "/"+fileName);//創建一個文件輸出流對象
InputStream inputStream = item.getInputStream();//創建一個輸入流
byte pool[] = new byte[1024];
int len = -1;
while((len = inputStream.read(pool, 0, pool.length)) != -1){
outputStream.write(pool, 0, len);
}
outputStream.flush();
outputStream.close();
inputStream.close();
//顯示最新插入的圖片
out.println("<img src=\"D:/Program Files/Android/workspace_Web/Catering/WebContent/images/menu/"+fileName+"\" alt=\""+fileName+"\" width=\"200px\" height=\"100px\"/><br/>");
}
}
out.println("上傳成功！");
gb = gbb.savaGoods(gb);
} catch (FileUploadException e) {
e.printStackTrace();
}
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request, response);
}
}
就這三個代碼，其實很簡單，自己理解一下。