jsp 文件安全下載

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class DownLoadServlet extends HttpServlet {
    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        String path = "C:/file";
        String fileName = request.getParameter("filename");
        File file = new File(path + "/" + fileName);
        //如果文件存在
        if (file.exists()) {
            //設置響應類型及響應頭
            response.setContentType("application/x-msdownload");
            response.addHeader("Content-Disposition", "attachment; filename=\""


                + fileName + "\"");
        //讀取文件
        InputStream inputStream = new FileInputStream(file);
        BufferedInputStream bis = new BufferedInputStream(inputStream);
        byte[] bytes = new byte[1024];
        ServletOutputStream outStream = response.getOutputStream();
        BufferedOutputStream bos = new BufferedOutputStream(outStream);
        int readLength = 0;
        while ((readLength = bis.read(bytes)) != -1) {
            bos.write(bytes, 0, readLength);
        }
        //釋放資源
        inputStream.close();
        bis.close();
        bos.flush();
        outStream.close();
        bos.close();
    }
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
    doGet(request, response);
}

}</pre>