DownloadFileWithNginxAction.java

DownloadFileWithNginxAction.java

package com.servlet3.demo;

import java.io.IOException;
import java.io.Writer;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.io.FilenameUtils;
import org.apache.commons.lang.StringUtils;
import org.apache.log4j.Logger;

/**
 * 控制检测用户具有权限下载文件，转交给ngxin处理
 * 
 * @author yongboy
 * @time 2012-1-18
 * @version 1.0
 */
@WebServlet("/download")
public class DownloadFileWithNginxAction extends HttpServlet {
	private static final long serialVersionUID = 1L;
	private final Logger log = Logger
			.getLogger(DownloadFileWithNginxAction.class);

	protected void doGet(HttpServletRequest request,
			HttpServletResponse response) throws ServletException, IOException {
		String filePath = request.getParameter("path");

		boolean right = checkRight(filePath);

		if (!right) {
			output(response, "您的下载有误！");
			return;
		}

		// 下面文件处理下载文件时，是不需要编码的，不会出现中文乱码问题
		String fileName = FilenameUtils.getName(filePath);

		response.setHeader("Content-Type", "application/octet-stream");
		response.setHeader("Content-disposition", "attachment; filename="
				+ fileName);

		// 当前用户符合下载要求，转发给Nginx进行下载处理
		response.setHeader("X-Accel-Redirect", "/downloads/" + filePath);
		response.setHeader("X-Accel-Charset", "utf-8");

		log.debug("send to nginx to handle file download ...");
	}

	/**
	 * 下载逻辑的简单实现版本
	 * 
	 * @author yongboy
	 * @time 2012-1-18
	 * 
	 * @param path
	 * @return
	 */
	private boolean checkRight(String path) {
		if (StringUtils.isBlank(path)) {
			return false;
		}

		return true;
	}

	private static void output(HttpServletResponse response, String message) {
		try {
			response.setContentType("text/html; charset=UTF-8");
			Writer out = response.getWriter();
			out.write(message);
			out.flush();
			out.close();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}