文件下载方法

1. 通用下载

package com.stig.business.web.contoller;

import com.stig.business.web.mobel.po.EbssFileInfo;
import com.stig.common.constant.Constants;
import com.stig.common.properties.BusStopSignProperties;
import com.stig.common.utils.RedisUtils;
import com.stig.common.utils.StringUtils;
import com.stig.common.utils.file.FileUtils;
import lombok.extern.slf4j.Slf4j;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.*;

import javax.annotation.Resource;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.net.URLEncoder;
import java.nio.charset.StandardCharsets;

@Slf4j
@CrossOrigin
@RestController
@RequestMapping("/common")
public class CommonController {

    @Resource
    private RedisUtils redisUtils;


    /**
     * 通用下载请求(文件id方式)
     *
     */
    @GetMapping("download/{fileId}")
    public void fileDownload(@PathVariable("fileId") String fileId, HttpServletResponse response,
                             HttpServletRequest request) {
        EbssFileInfo ebssFileInfo = redisUtils.getCacheMapValue(Constants.REDIS_ADVERT_RESOURCE_KEY,fileId);
        if(ebssFileInfo == null || StringUtils.isBlank(ebssFileInfo.getFilePath())){
            response.setStatus(HttpStatus.NOT_FOUND.value());
            return;
        }
        String realFilePath = BusStopSignProperties.getProfile() + StringUtils.substring(ebssFileInfo.getFilePath(),Constants.RESOURCE_PREFIX.length());
        try {
            response.setContentType(MediaType.APPLICATION_OCTET_STREAM_VALUE);
            String encode = URLEncoder.encode(ebssFileInfo.getOriginalFilename(), StandardCharsets.UTF_8.toString());
            String percentEncodedFileName = encode.replaceAll("\\+", "%20");
            StringBuilder contentDispositionValue = new StringBuilder();
            contentDispositionValue.append("attachment; filename=")
                    .append(percentEncodedFileName)
                    .append(";")
                    .append("filename*=")
                    .append("utf-8''")
                    .append(percentEncodedFileName);
            response.addHeader("Access-Control-Expose-Headers", "Content-Disposition,download-filename");
            response.setHeader("Content-disposition", contentDispositionValue.toString());
            response.setHeader("download-filename", percentEncodedFileName);
            FileUtils.writeBytes(realFilePath, response.getOutputStream());
        } catch (Exception e) {
            log.error("下载文件失败", e);
        }
    }

}