blog.Ring.idv.tw
一般我們常見的HTML輸入型態(例如：text、radio、select…)都是使用「application/x-www-form-urlencoded」的編碼方式，但要傳送檔案至伺服端時，編碼方式則是要仰賴「multipart/form-data」，由於兩者的編碼方式不同，所以這裡提供一個「FileUpload」的小範例~
必要的package如下：
HTML
<%@page language="java" contentType="text/html;charset=utf-8"%>
<html>
<head>
<title>檔案上傳</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body>
<b>檔案上傳</b></font></p>
<form name="UploadForm" enctype="multipart/form-data" method="post" action="fileupload.dan">
<input type="file" name="File1" size="20" maxlength="20"> <br>
<input type="text" name="File2" size="20" maxlength="20"> <br>
<input type="submit"value="上傳">
</form>
</body>
</html>
Servlet
import java.io.File;
import java.io.IOException;
import java.util.Iterator;
import java.util.List;
import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
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.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
public class FileUpload extends HttpServlet
{
private String base;
public void init(ServletConfig sc) throws ServletException
{
ServletContext sco = sc.getServletContext();
base = sco.getRealPath("/");
}
public void doPost(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException
{
boolean isMultipart = ServletFileUpload.isMultipartContent(req);
try
{
if(isMultipart)
{
DiskFileItemFactory factory = new DiskFileItemFactory();
factory.setSizeThreshold(4096);
factory.setRepository(new File(base+"temp"));
ServletFileUpload upload = new ServletFileUpload(factory);
upload.setSizeMax(10000000);
List items = upload.parseRequest(req);
Iterator iter = items.iterator();
while(iter.hasNext())
{
FileItem item = (FileItem) iter.next();
if (item.isFormField())
{
String name = item.getFieldName();
String value = item.getString();
System.out.println("name:"+name+" value:"+value);
} else {
String fieldName = item.getFieldName();
String fileName = item.getName();
String contentType = item.getContentType();
boolean isInMemory = item.isInMemory();
long sizeInBytes = item.getSize();
System.out.println("fieldName:"+fieldName+" fileName:"+fileName);
File to = new File(base+"upload",fileName);
item.write(to);
}
}
}
} catch (Exception e)
{
e.printStackTrace();
}
}
}
