Java實現(xiàn)文件上傳至服務器的方法
在我們的web開發(fā)中,很多的時候都需要把本機的一些文件上傳到web服務器上面去。
如:一個BBS系統(tǒng),當用戶使用這是系統(tǒng)的時候,能把本機的一些圖片,文檔上傳到服務器上面去。然后其他用戶可以去下載這些文件,那么這樣的話,我們可以自己編程實現(xiàn)文件的上傳
但是更好的方式是使用一些已有的組件幫助我們實現(xiàn)這種上傳功能。
常用的上傳組件:
Apache 的 Commons FileUpload
JavaZoom的UploadBean
jspSmartUpload
upload.jsp
代碼;
<%@ page language="java" contentType="text/html; charset=UTF-8"%>
<html>
<head>
<title>using commons Upload to upload file </title>
</head>
<style>
* { font-family: "宋體"; font-size: 14px }
</style>
<body>
<p align="center"> 請您選擇需要上傳的文件</p>
<form id="form1" name="form1" method="post" action="servlet/fileServlet" enctype="multipart/form-data">
<table border="0" align="center">
<tr>
<td>上傳人:</td>
<td>
<input name="name" type="text" id="name" size="20" ></td>
</tr>
<tr>
<td>上傳文件:</td>
<td><input name="file" type="file" size="20" ></td>
</tr>
<tr>
<td></td><td>
<input type="submit" name="submit" value="提交" >
<input type="reset" name="reset" value="重置" >
</td>
</tr>
</table>
</form>
</body>
</html>
FileUploadServlet.java代碼:
/**
*
*/
package com.b510.example;
import java.io.File;
import java.io.IOException;
import java.util.*;
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.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
/**
*
* @author XHW
*
* @date 2011-7-26
*
*/
public class FileUploadServlet extends HttpServlet {
private static final long serialVersionUID = -7744625344830285257L;
private ServletContext sc;
private String savePath;
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request, response);
}
public void init(ServletConfig config) {
// 在web.xml中設置的一個初始化參數(shù)
savePath = config.getInitParameter("savePath");
sc = config.getServletContext();
}
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
request.setCharacterEncoding("UTF-8");
DiskFileItemFactory factory = new DiskFileItemFactory();
ServletFileUpload upload = new ServletFileUpload(factory);
try {
List items = upload.parseRequest(request);
Iterator itr = items.iterator();
while (itr.hasNext()) {
FileItem item = (FileItem) itr.next();
if (item.isFormField()) {
System.out.println("表單參數(shù)名:" + item.getFieldName() + ",表單參數(shù)值:" + item.getString("UTF-8"));
} else {
if (item.getName() != null && !item.getName().equals("")) {
System.out.println("上傳文件的大小:" + item.getSize());
System.out.println("上傳文件的類型:" + item.getContentType());
// item.getName()返回上傳文件在客戶端的完整路徑名稱
System.out.println("上傳文件的名稱:" + item.getName());
File tempFile = new File(item.getName());
?。蟼魑募谋4媛窂?
File file = new File(sc.getRealPath("/") + savePath, tempFile.getName());
item.write(file);
request.setAttribute("upload.message", "上傳文件成功!");
}else{
request.setAttribute("upload.message", "沒有選擇上傳文件!");
}
}
}
}catch(FileUploadException e){
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
request.setAttribute("upload.message", "上傳文件失??!");
}
request.getRequestDispatcher("/uploadResult.jsp").forward(request, response);
}
}
uploadResult.jsp代碼:
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>uploadResult</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css" rel="external nofollow" >
-->
</head>
<body>
${requestScope['upload.message'] }
<a href="/upload/uploadFile.jsp" rel="external nofollow" >上傳文件</a>
</body>
</html>
web.xml
<servlet> <description>This is the description of my J2EE component</description> <display-name>This is the display name of my J2EE component</display-name> <servlet-name>FileUploadServlet</servlet-name> <servlet-class>com.b510.example.FileUploadServlet</servlet-class> <!--設置初始化參數(shù)--> <init-param> <param-name>savePath</param-name> <param-value>uploads</param-value> </init-param> </servlet> <servlet-mapping> <servlet-name>FileUploadServlet</servlet-name> <url-pattern>/servlet/fileServlet</url-pattern> </servlet-mapping>
本文已被整理到了《Java上傳操作技巧匯總》,歡迎大家學習閱讀。
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