原理：
我們知道一般的jsp程序是在wtpwebapps或者webapps文件夾下的，本教程默認在webapps下，而在服務器上的話，需要將jsp程序導出的war包放到webapps文件夾下。然後訪問 域名/項目名稱/文件 即可訪問這個文件。這個程序是一個上傳程序，將用戶（其他同學好友）的war包直接上傳至webapps，然後生成直接訪問這個網址的鏈接。
閒話少敘，代碼整起：
上傳代碼，沒有UI，倒數3-4行爲示例可刪
upload.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>文件上傳</title>
</head>
<body style="text-align: center;">
<h1>War文件上傳</h1>
<form method="post" action="upload.do" enctype="multipart/form-data">
選擇一個文件:(務必爲.war文件)<br>
<input type="file" name="uploadFile" />
<br/><br/>
<input type="submit" value="上傳" /><br><br><br><br>
</form>
<br><font color="red" size="16">如何生成war文件?看下圖</font><br><br>
<img alt="" src="tu.png">
</body>
</html>
結果界面 返回結果 message.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>文件上傳結果</title>
</head>
<body style="text-align: center;">
<h2>${message}</h2>
<h2>點擊下方鏈接跳轉到你的項目目錄</h2>
<a href="${yoururl}">${yoururl}</a>
</body>
</html>
UploadServlet
package servlet;
import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.List;
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.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
/**
* Servlet implementation class UploadServlet
*/
@WebServlet("/admin/upload.do")
public class UploadServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
private static final String URL = "http://你的域名/";
// 上傳文件存儲目錄
private static final String UPLOAD_DIRECTORY = "upload";
// 上傳配置
private static final int MEMORY_THRESHOLD = 1024 * 1024 * 3; // 3MB
private static final int MAX_FILE_SIZE = 1024 * 1024 * 40; // 40MB
private static final int MAX_REQUEST_SIZE = 1024 * 1024 * 50; // 50MB /**
public UploadServlet() {
super();
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
response.getWriter().append("Served at: ").append(request.getContextPath());
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
* a上傳數據及保存文件
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
// 檢測是否爲多媒體上傳
if (!ServletFileUpload.isMultipartContent(request)) {
// 如果不是則停止
PrintWriter writer = response.getWriter();
writer.println("Error: 表單必須包含 enctype=multipart/form-data");
writer.flush();
return;
}
// 配置上傳參數
DiskFileItemFactory factory = new DiskFileItemFactory();
// 設置內存臨界值 - 超過後將產生臨時文件並存儲於臨時目錄中
factory.setSizeThreshold(MEMORY_THRESHOLD);
// 設置臨時存儲目錄
factory.setRepository(new File(System.getProperty("java.io.tmpdir")));
ServletFileUpload upload = new ServletFileUpload(factory);
// 設置最大文件上傳值
upload.setFileSizeMax(MAX_FILE_SIZE);
// 設置最大請求值 (包含文件和表單數據)
upload.setSizeMax(MAX_REQUEST_SIZE);
// 中文處理
upload.setHeaderEncoding("UTF-8");
// 構造臨時路徑來存儲上傳的文件
// 這個路徑相對當前應用的目錄
//String uploadPath = getServletContext().getRealPath("/") + File.separator + UPLOAD_DIRECTORY;
String uploadPath = getServletContext().getRealPath("/");
File aFile = new File(uploadPath).getParentFile();
uploadPath = aFile.toString();
// 如果目錄不存在則創建
File uploadDir = new File(uploadPath);
if (!uploadDir.exists()) {
uploadDir.mkdir();
}
try {
// 解析請求的內容提取文件數據
@SuppressWarnings("unchecked")
List<FileItem> formItems = upload.parseRequest(request);
if (formItems != null && formItems.size() > 0) {
// 迭代表單數據
for (FileItem item : formItems) {
// 處理不在表單中的字段
if (!item.isFormField()) {
String fileName = new File(item.getName()).getName();
String filePath = uploadPath + File.separator + fileName;
File storeFile = new File(filePath);
// 在控制檯輸出文件的上傳路徑
System.out.println(filePath);
// 保存文件到硬盤
item.write(storeFile);
request.setAttribute("message",
"文件上傳成功!");
fileName = fileName.substring(0,fileName.indexOf("."));
request.setAttribute("yoururl",URL + fileName);
}
}
}
} catch (Exception ex) {
request.setAttribute("message",
"錯誤信息: " + ex.getMessage());
}
// 跳轉到 message.jsp
getServletContext().getRequestDispatcher("/admin/message.jsp").forward(
request, response);
}
}
代碼第21行@WebServlet("/admin/upload.do")需要自行修改，我的這兩個jsp在WebContent下的admin文件夾下。
代碼第25行 private static final String URL = "xxx";改爲自己的域名
效果：（上傳即可訪問，有時候需要等幾秒，多刷新幾次）
