- 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;
- /**
- * 文件下载类。为了防止客户端浏览器直接打开目标文件(例如在装了MS Office套件的Windows中的IE浏览器可能就会直接在IE浏览器中打开你想下载的doc或者xls文件),在响应头里加入强制下载的MIME类型。
- */
- 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;
- }
- // 读取文件流
- fis = new java.io.FileInputStream(file);
- // 设置下载保存的文件名
- 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("文件下载完成,文件大小:"+ byteCount +",总共用时:"+ (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>文件下载</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;
- }
- }
- //该片段来自于http://www.codesnippet.cn/detail/2711201411080.html
来源: http://www.codesnippet.cn/detail/2711201411080.html