使用apache提供的兩個jar實現上傳，分別是commons-io-1.4.jar和commons-io-1.4.jar
兩個頁面upload2.jsp和result2.jsp、UploadServlet
upload2.jsp上傳兩個檔案
<form action="/struts2/UploadServlet" method="post" enctype="multipart/form-data">
username:<input type="text" name="username"><br>
password:<input type="password" name="password"><br>
file1:<input type="file" name="file1"><br>
file2:<input type="file" name="file2"><br>
<input type="submit" name="submit" value=" submit ">
</form>
UploadServlet.java
package com.test.servlet;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.List;
import javax.servlet.ServletException;
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;
public class UploadServlet extends HttpServlet {
@SuppressWarnings("unchecked")
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//執行個體化一個磁碟檔案工廠,用來配置上傳組件ServletFileUpload
DiskFileItemFactory factory = new DiskFileItemFactory();
//設定檔案上傳路徑
String path = request.getRealPath("/upload");
//當上傳檔案大於設定大小時，存放臨時檔案的目錄,web根目錄下upload目錄
factory.setRepository(new File(path));
//設定上傳檔案時用於臨時存放檔案的記憶體大小,這裡是1M,多於的部分將存在硬碟
factory.setSizeThreshold(1024 * 1024);
//用上面的工廠執行個體化上傳組件
ServletFileUpload upload = new ServletFileUpload();
//如果ServletFileUpload執行個體中不設定上面的Factory則報java.lang.NullPointerException: No FileItemFactory has been set.
upload.setFileItemFactory(factory);
try {
//解析request，處理用戶端傳來的所有表單資料，返回list（包括file和非file類型）
List<FileItem> list = upload.parseRequest(request);
for (FileItem item : list) {
// 判斷用戶端傳來的form表單中 是否是一個file類型
//普通表單類型
if (item.isFormField()) {
//得到檔案的名稱
String name = item.getFieldName();
System.out.println(name);
//得到檔案值
String value = item.getString("gbk");
request.setAttribute(name, value);
}
//檔案類型
else {
String name = item.getFieldName();
//form中，類型為file時，getName（）方法才能擷取到檔案名稱，否則為空白
String value = item.getName();
// 擷取真本文件名 ，針對不同瀏覽器
int start = value.lastIndexOf("//");
String fileName = value.substring(start + 1);
//儲存檔案名稱到request中
request.setAttribute(name, fileName);
// 第一種方式
// //定義檔案輸出資料流
// OutputStream os = new FileOutputStream(path);
//
// //獲得輸入資料流,
// InputStream is = item.getInputStream();
//
// //將輸入資料流資料寫入輸出資料流中
// byte[] buffer = new byte[400];
//
// int length = 0;
//
// while ((length = is.read(buffer)) > 0) {
// //將輸入資料流資料寫入輸出資料流中
// os.write(buffer, 0, length);
// }
//
// os.close();
// is.close();
//第二種方式
item.write(new File(path,fileName));
}
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//轉寄
request.getRequestDispatcher("upload/result2.jsp").forward(request,
response);
}
}
result2.jsp
<body>
username:${requestScope.username }<br>
password:${requestScope.password }<br>
file1:${requestScope.file1 }<br>
file2:${requestScope.file2 }
</body>
此時實現檔案上傳的第二種方式，struts底層的實現方式
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