package?org.gyt.fileUploadDownload;

import?java.io.File;
import?java.io.FileInputStream;
import?java.io.IOException;
import?java.io.OutputStream;
import?java.net.URLEncoder;

import?javax.servlet.ServletException;
import?javax.servlet.annotation.WebServlet;
import?javax.servlet.http.HttpServlet;
import?javax.servlet.http.HttpServletRequest;
import?javax.servlet.http.HttpServletResponse;

/**
?*?Servlet?implementation?class?DownloadServlet
?*/
@WebServlet（“/DownloadServlet“）
public?class?DownloadServlet?extends?HttpServlet?{
	private?static?final?long?serialVersionUID?=?1L;
????private?static?String?filePath?=?“404“;
????/**
?????*?@see?HttpServlet#HttpServlet（）
?????*/
????public?DownloadServlet（）?{
????????super（）;
????????//?TODO?Auto-generated?constructor?stub
????}

	/**
	?*?@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（））;
		//?下載文件
		System.out.println（“下載文件：“）;
		//?文件名
		String?fileName?=?request.getParameter（“filename“）;?//文件名_UUID
		fileName?=?new?String（fileName.getBytes（“iso8859-1“）?“UTF-8“）;
		//?文件保存在/WEB-INF/file中
		String?fileStorageRootPath?=?this.getServletContext（）.getRealPath（“/WEB-INF/file“）;
		//?通過文件名找出文件所在目錄?返回絕對路徑
		findFileStoragePathByFileName（fileName?new?File（fileStorageRootPath））;
		System.out.println（“Download?File:?“?+?filePath）;
		//?得到該文件
		if?（filePath.equals（“404“））?{
			request.setAttribute（“message“?“錯誤“）;
			request.getRequestDispatcher（“/message.jsp“）.forward（request?response）;
		}
		File?file?=?new?File（filePath）;
		//?若不存在
		if?（file?!=?null?&&?!file.exists（））?{
			request.setAttribute（“message“?“資源已被刪除！“）;
			request.getRequestDispatcher（“/message.jsp“）.forward（request?response）;
			return?;
		}
		//?處理文件名
		String?realName?=?fileName.substring（fileName.indexOf（“_“）+1）;
		//?設置相應頭，控制瀏覽器下載文件
		response.setHeader（“content-disposition“?“attachment;filename=“?+?URLEncoder.encode（realName?“UTF-8“））;
		//?讀取要下載的文件，保存到輸入流
		
		FileInputStream?inputStream?=?new?FileInputStream（filePath）;
		//?創建輸出流
		OutputStream?outputStream?=?response.getOutputStream（）;
		//?創建緩沖區
		byte[]?buffer?=?new?byte[1024];
		int?len?=?0;
		while?（（len=inputStream.read（buffer））?>?0）?{
			//?輸出緩沖區內容到瀏覽器，實現下載
			outputStream.write（buffer?0?len）;			
		}
		//?關閉流
		inputStream.close（）;
		outputStream.close（）;
	}
	/**
	?*?
	?*?@throws?IOException?
	?*?@title：findFileStoragePathByFileName
	?*?@Description:?根據文件名找到所在路徑?返回絕對路徑
	?*?@Param:?@param?fileName
	?*?@Param:?@param?fileStorageRootPath
	?*?@Param:?@return?返回絕對路徑
	?*?@Return:?String
	?*/
	private?void?findFileStoragePathByFileName（String?fileName?File?file）?throws?IOException?{
		//?TODO?Auto-generated?method?stub
		
	

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----

?????文件???????1418??2018-12-04?23:16??FileUploadDownload\.classpath

?????文件????????918??2018-12-04?23:14??FileUploadDownload\.project

?????文件????????567??2018-12-04?23:14??FileUploadDownload\.settings\.jsdtscope

?????文件????????364??2018-12-04?23:14??FileUploadDownload\.settings\org.eclipse.jdt.core.prefs

?????文件????????506??2018-12-04?23:14??FileUploadDownload\.settings\org.eclipse.wst.common.component

?????文件????????345??2018-12-04?23:14??FileUploadDownload\.settings\org.eclipse.wst.common.project.facet.core.xml

?????文件?????????49??2018-12-04?23:14??FileUploadDownload\.settings\org.eclipse.wst.jsdt.ui.superType.container

?????文件??????????6??2018-12-04?23:14??FileUploadDownload\.settings\org.eclipse.wst.jsdt.ui.superType.name

?????文件???????4035??2018-12-04?23:16??FileUploadDownload\build\classes\org\gyt\fileUploadDownload\DownloadServlet.class

?????文件???????3026??2018-12-04?23:22??FileUploadDownload\build\classes\org\gyt\fileUploadDownload\ListFileServlet.class

?????文件???????1252??2018-12-04?23:24??FileUploadDownload\build\classes\org\gyt\fileUploadDownload\UploadServlet$1.class

?????文件???????7083??2018-12-04?23:24??FileUploadDownload\build\classes\org\gyt\fileUploadDownload\UploadServlet.class

?????文件???????4352??2018-12-04?22:08??FileUploadDownload\src\org\gyt\fileUploadDownload\DownloadServlet.java

?????文件???????2994??2018-12-04?23:22??FileUploadDownload\src\org\gyt\fileUploadDownload\ListFileServlet.java

?????文件???????7599??2018-12-04?23:24??FileUploadDownload\src\org\gyt\fileUploadDownload\UploadServlet.java

?????文件???????6162??2018-12-04?23:12??FileUploadDownload\WebContent\home.jsp

?????文件?????????39??2018-12-04?23:14??FileUploadDownload\WebContent\meta-INF\MANIFEST.MF

?????文件??????53485??2018-12-04?18:49??FileUploadDownload\WebContent\static\css\animate.min.css

?????文件?????117154??2018-12-04?18:49??FileUploadDownload\WebContent\static\css\bootstrap.min.css

?????文件??????15121??2018-12-04?18:49??FileUploadDownload\WebContent\static\css\style.css

?????文件???????1097??2018-12-04?18:49??FileUploadDownload\WebContent\static\css\style2.css

?????文件??????10038??2018-12-04?18:49??FileUploadDownload\WebContent\static\css\vegas.min.css

?????文件?????823845??2018-12-04?18:49??FileUploadDownload\WebContent\static\img\bannerq1.jpg

?????文件?????940115??2018-12-04?18:49??FileUploadDownload\WebContent\static\img\bannerq2.jpg

?????文件????1447656??2018-12-04?18:49??FileUploadDownload\WebContent\static\img\bannerq3.jpg

?????文件?????152207??2018-12-04?18:49??FileUploadDownload\WebContent\static\img\bannerq4.jpg

?????文件?????619853??2018-12-04?18:49??FileUploadDownload\WebContent\static\img\bannerq5.jpg

?????文件?????228356??2018-12-04?18:49??FileUploadDownload\WebContent\static\img\bannerq6.jpg

?????文件?????499486??2018-12-04?18:49??FileUploadDownload\WebContent\static\img\bannerq7.jpg

?????文件????????213??2018-12-04?18:49??FileUploadDownload\WebContent\static\img\overlay.png

............此處省略39個文件信息