서버의 파일 다운로드 처리

<%@ include file="/library/lib_base.jsp" %>
<%@ page contentType="text/html; charset=utf-8" %>

<%
	int parm_file_uid = Util.nvl(request.getParameter("parm_file_uid"), 0);

	// 접근 유효성 체크
	if(util.getSession("USR_ID").equals("") || parm_file_uid == 0)
	{
		util.showMessage("로그인이 필요한 서비스 입니다!", "history.back()");
		return;
	}

	AttachedFileQuery attachedFileQuery = new AttachedFileQuery();
	AttachedFile attachedFile = attachedFileQuery.selectAttachedFile(parm_file_uid);
	
	File fromFile = new File(Config.CFG_SYSTEMDIR + attachedFile.getFile_path());
	
	if(fromFile.exists() && fromFile.isFile())
	{
		BufferedInputStream		biStream = null;
		BufferedOutputStream	boStream = null;
		
		try
		{
			response.reset();
			response.setContentType("application/octet-stream;charset=utf-8"); 
			response.setHeader("Accept-Ranges", "bytes");
			response.setHeader("Content-Disposition", "attachment; filename=\""+ URLEncoder.encode(attachedFile.getFile_srcFileName(), "UTF-8") +"\";");
			response.setHeader("Content-Description", "JSP Generated Data");
			response.setContentLength((int)attachedFile.getFile_phyFileSize());
			
			biStream = new BufferedInputStream(new FileInputStream(fromFile));
			boStream = new BufferedOutputStream(response.getOutputStream());
			
			byte[] buffer = new byte[1024];
			int len = 0;
			
			out.clear();
			
			while((len = biStream.read(buffer)) != -1)
			{
				boStream.write(buffer, 0, len);
				boStream.flush();
			}
		}
		catch(Exception e)
		{
			Log.write(e);
			util.showMessage("파일 다운로드를 실패하였습니다!", "history.back()");
			return;
		}
		finally
		{
			if(biStream != null) try{biStream.close();}catch(IOException e){}
			if(boStream != null) try{boStream.close();}catch(IOException e){}
		}
	}
	else
	{
		util.showMessage("존재하지 않는 파일입니다!", "history.back()");
		return;
	}
%>

http get으로 다른 사이트의 파일을 다운로드하기

<%@page import="java.io.FileOutputStream"%>
<%@page import="java.io.File"%>
<%@page import="java.net.URLDecoder"%>
<%@page import="java.util.regex.Matcher"%>
<%@page import="java.util.regex.Pattern"%>
<%@page import="java.util.List"%>
<%@page import="java.util.Map"%>
<%@page import="java.io.InputStream"%>
<%@page import="java.net.URL"%>
<%@page import="java.net.HttpURLConnection"%>
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<%
    String actionUrl = "http://blog.daonelab.com/outer/download.do?id=5fba4bc4-ce51-4b59-9ee1-003c7fe1288c-file";
    
    URL _downloadUrl = new URL(actionUrl);
    
    HttpURLConnection _conn = (HttpURLConnection)_downloadUrl.openConnection();
    _conn.setRequestMethod("GET");
    _conn.connect();
    
    // 파일명 추출
    Map<String, List<String>> _header = _conn.getHeaderFields();
    String _disposition = (String)(_header.get("Content-Disposition").get(0));
    
    Pattern pattern = Pattern.compile("^.+filename\\*=(.+)''(.+)$");
    Matcher matcher = pattern.matcher(_disposition);
    matcher.matches();
    
    String _enc         = matcher.group(1);
    String _fileName    = URLDecoder.decode(matcher.group(2), _enc);
    
    // 다운로드 경로 및 파일지정
    String _dirPath = request.getServletContext().getRealPath("/");
    File _file = new File(String.format("%s%s%s", _dirPath, File.separator, _fileName));
    FileOutputStream os = new FileOutputStream(_file);

    InputStream is = _conn.getInputStream();
    
    int read = -1;
    byte[] bytes = new byte[1024];
    
    while ((read = is.read(bytes)) != -1)
    {
        os.write(bytes, 0, read);
    }
    
    is.close();
    os.close();
%>