SpringBoot之文件下载

package org.springboot.controller;

import org.springboot.constant.Constant;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.net.URLEncoder;

/**
 * @Auther:GongXingRui
 * @Date:2018/12/24
 * @Description:
 **/
@Controller
public class FileDownload {

        //实现Spring Boot 的文件下载功能，映射网址为/download
        @RequestMapping("/download")
        public String downloadFile(HttpServletRequest request,
                                   HttpServletResponse response) throws UnsupportedEncodingException {
//            String picPath = "C:/Temp/pic";
            String picPath = Constant.CONFIG_PROPERTIES.getProperty("download.path");

            // 获取指定目录下的第一个文件
            File scFileDir = new File(picPath);
            File TrxFiles[] = scFileDir.listFiles();
            System.out.println(TrxFiles[0]);
            String fileName = TrxFiles[0].getName(); //下载的文件名

            // 如果文件名不为空，则进行下载
            if (fileName != null) {
                //设置文件路径
                File file = new File(picPath, fileName);

                // 如果文件名存在，则进行下载
                if (file.exists()) {
                    // 配置文件下载
                    response.setHeader("content-type", "application/octet-stream");
                    response.setContentType("application/octet-stream");
                    // 下载文件能正常显示中文
                    response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(fileName, "UTF-8"));

                    // 实现文件下载
                    byte[] buffer = new byte[1024];
                    FileInputStream fis = null;
                    BufferedInputStream bis = null;
                    try {
                        fis = new FileInputStream(file);
                        bis = new BufferedInputStream(fis);
                        OutputStream os = response.getOutputStream();
                        int i = bis.read(buffer);
                        while (i != -1) {
                            os.write(buffer, 0, i);
                            i = bis.read(buffer);
                        }
                        System.out.println("Download the file successfully!");
                    }
                    catch (Exception e) {
                        System.out.println("Download the file failed!");
                    }
                    finally {
                        if (bis != null) {
                            try {
                                bis.close();
                            } catch (IOException e) {
                                e.printStackTrace();
                            }
                        }
                        if (fis != null) {
                            try {
                                fis.close();
                            } catch (IOException e) {
                                e.printStackTrace();
                            }
                        }
                    }
                }
            }
            return null;
        }


}