看部署方式，jvm启动-浏览器直接访问【IP:PORT/sync/service/getdata】；部署在tomcat中【tomcat配置的IP:PORT/项目名/sync/service/getdata】

import javafx.application.Application;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;
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;
import java.nio.charset.Charset;
import java.util.Date;

@Controller
@SpringBootApplication
@MapperScan("cy.test.unit.dao")
public class UnitApplication extends SpringBootServletInitializer {

    @Value("${CSVFile.location}")
    private String location;

    public static void main(String[] args) {
        SpringApplication.run(UnitApplication.class, args);
    }

    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {
        return builder.sources(UnitApplication.class);
    }

    /**
     * 文件下载
     *
     * @param request
     * @param response
     * @return
     */
    @RequestMapping("/sync/service/getdata")
    public void downloadFile(HttpServletRequest request,
                          HttpServletResponse response, String name) throws Exception {
        String FullPath = location + name;//将文件的统一储存路径和文件名拼接得到文件全路径
        File packetFile = new File(FullPath);
        String fileName = packetFile.getName();
        File file = new File(FullPath);
        // 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("text/plain;charset=UTF-8");
            // 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
            //指定编码
            InputStreamReader reader = new InputStreamReader(new FileInputStream(file));
            OutputStream os = response.getOutputStream();
            OutputStreamWriter writer = new OutputStreamWriter(os, "UTF-8");
            char[] chs = new char[1024];
            int len = 0;
            while ((len = reader.read(chs)) != -1) {
                writer.write(new String(chs, 0, len));
            }
            reader.close();
            writer.flush();
            writer.close();
        } else {//对应文件不存在
        }
    }
}