【javaweb:servlet】從服務端下載中文名稱檔案應該注意的問題!!!
阿新 • • 發佈:2019-01-06
請看下面的程式碼,與普通的英文名稱檔案下載方式不同,裡面涉及到編碼和解碼的問題!
package com.content; import java.io.FileInputStream; import java.io.IOException; import java.io.InputStream; import java.net.URLEncoder; import javax.servlet.ServletException; import javax.servlet.ServletOutputStream; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import sun.misc.BASE64Encoder; public class DownLoadServlet2 extends HttpServlet { protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //*******檔名稱是中文的下載******* //獲得要下載的檔案的名稱 String filename = request.getParameter("filename");//????.jpg //解決獲得中文引數的亂碼----下節課講 filename = new String(filename.getBytes("ISO8859-1"),"UTF-8");//美女.jpg //獲得請求頭中的User-Agent String agent = request.getHeader("User-Agent"); //根據不同瀏覽器進行不同的編碼 String filenameEncoder = ""; if (agent.contains("MSIE")) { // IE瀏覽器 filenameEncoder = URLEncoder.encode(filename, "utf-8"); filenameEncoder = filenameEncoder.replace("+", " "); } else if (agent.contains("Firefox")) { // 火狐瀏覽器 BASE64Encoder base64Encoder = new BASE64Encoder(); filenameEncoder = "=?utf-8?B?" + base64Encoder.encode(filename.getBytes("utf-8")) + "?="; } else { // 其它瀏覽器 filenameEncoder = URLEncoder.encode(filename, "utf-8"); } //要下載的這個檔案的型別-----客戶端通過檔案的MIME型別去區分型別 response.setContentType(this.getServletContext().getMimeType(filename)); //告訴客戶端該檔案不是直接解析 而是以附件形式開啟(下載)----filename="+filename 客戶端預設對名字進行解碼 response.setHeader("Content-Disposition", "attachment;filename="+filenameEncoder); //這兒的filenameEncoder是對"美女.jpg"進行鍼對不同瀏覽器進行的編碼, //不再是"美女.jpg",因為它不識別(導致下載的檔案沒名稱) //獲取檔案的絕對路徑 String path = this.getServletContext().getRealPath("download/"+filename); //獲得該檔案的輸入流 InputStream in = new FileInputStream(path); //獲得輸出流---通過response獲得的輸出流 用於向客戶端寫內容 ServletOutputStream out = response.getOutputStream(); //檔案拷貝的模板程式碼 int len = 0; byte[] buffer = new byte[1024]; while((len=in.read(buffer))>0){ out.write(buffer, 0, len); } in.close(); //out.close();out.close()可不必寫 } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } }