程序師世界是廣大編程愛好者互助、分享、學習的平台,程序師世界有你更精彩!
首頁
編程語言
C語言|JAVA編程
Python編程
網頁編程
ASP編程|PHP編程
JSP編程
數據庫知識
MYSQL數據庫|SqlServer數據庫
Oracle數據庫|DB2數據庫
 程式師世界 >> 編程語言 >> 網頁編程 >> JSP編程 >> 關於JSP >> servlet實現文件下載的實用類分享

servlet實現文件下載的實用類分享

編輯:關於JSP

     servlet文件下載類,為了防止客戶端浏覽器直接打開目標文件,在響應頭裡加入強制下載的MIME類型,大家參考使用吧

      代碼如下: package com;   import java.io.IOException; import java.io.PrintWriter; import java.net.URLEncoder; import java.util.Date;   import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse;   import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory;   import com.sun.xml.internal.messaging.saaj.packaging.mime.internet.MimeUtility;     /**  * 文件下載類。為了防止客戶端浏覽器直接打開目標文件(例如在裝了MS Office套件的Windows中的IE浏覽器可能就會直接在IE浏覽器中打開你想下載的doc或者xls文件),在響應頭裡加入強制下載的MIME類型。  */ public class DownloadFile extends HttpServlet {  private static final Log log = LogFactory.getLog(DownloadFile.class);    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException {   long timeStart = 0;   if(log.isDebugEnabled()){    timeStart=System.currentTimeMillis();   }   response.setContentType("application/x-download charset=UTF-8");   java.io.FileInputStream fis = null;   String filepath = request.getRealPath("");   javax.servlet.ServletOutputStream sos = null;   // System.out.println("DownloadFile filename:" + filename);   try {    if(request.getParameter("filename")==null      ||request.getParameter("showName")==null){     return;    }    String filename = request.getParameter("filename");    String showName = request.getParameter("showName");    request.setCharacterEncoding("UTF-8");    response.setCharacterEncoding("UTF-8");    java.io.File file = new java.io.File(filepath + filename);    if (!file.exists()) {     log.error(file.getAbsolutePath() + " 文件不存在!");     return;    }    // 讀取文件流    fis = new java.io.FileInputStream(file);    // 設置下載保存的文件名    sos = response.getOutputStream();    showName += filename.substring(filename.lastIndexOf("."));    String contentDisposition = "", browser = getBrowser(request);    if ("IE".equals(browser)) {     contentDisposition = "attachment; filename=" + URLEncoder.encode(showName, "UTF-8").replace("+", "%20");    } else if ("CH".equals(browser)) {     contentDisposition = "attachment; filename=" + MimeUtility.encodeText(showName, "UTF8", "B");    } else if ("SF".equals(browser)) {     contentDisposition = "attachment; filename=" + new String(showName.getBytes("UTF-8"), "ISO8859-1");    } else {     contentDisposition = "attachment; filename*=UTF-8''" + URLEncoder.encode(showName, "UTF-8").replace("+", "%20");    }    response.setHeader("Content-Disposition", contentDisposition);    int byteCount = 0;     if (fis != null) {     byte[] buff = new byte[1024];     int bytesRead;     while(-1 != (bytesRead = fis.read(buff, 0, buff.length))) {      sos.write(buff, 0, bytesRead);      sos.flush();      byteCount += bytesRead;     }     }    sos.flush();    if(log.isDebugEnabled()){     log.debug("文件下載完成,文件大小:"+ byteCount +",總共用時:"+ (new Date().getTime() - timeStart) +"毫秒。");    }   } catch(IOException ioe) {    ioe.printStackTrace();   } finally {    try {     if(fis!=null){      fis.close();     }    } catch (IOException e) {    } finally {     try {      if(sos!=null){       sos.close();      }     } catch (IOException e) {     }    }   }  }    public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {   response.setContentType("text/html");   PrintWriter out = response.getWriter();   out.println("<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">");   out.println("<html>");   out.println(" <head>");   out.println("   <title>文件下載</title>");   out.println("   <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />");   out.println(" </head>");   out.println(" <body>");   out.print(" This is ");   out.print(this.getClass().getName());   out.println(", using the POST method");   out.println(" </body>");   out.println("</html>");   out.flush();   out.close();  }    private String getBrowser(HttpServletRequest request) {   String userAgent = request.getHeader("USER-AGENT").toLowerCase();   if (userAgent != null) {    if (userAgent.indexOf("msie") >= 0) {     return "IE";    } else if (userAgent.indexOf("mozilla") >= 0) {     return "FF";    } else if (userAgent.indexOf("applewebkit") >= 0) {     return "CH";    } else if (userAgent.indexOf("safari") >= 0) {     return "SF";    } else if (userAgent.indexOf("opera") >= 0) {     return "OP";    }   }   return null;  } }    
    1. 上一頁:
    2. 下一頁:
    Copyright © 程式師世界 All Rights Reserved