• 需求：因为要通过feign服务间调用显示资源服务器产生的图片资源，但是仅仅调用这个显示二维码图片的接口并不能成功调用，因此这里记录仪下我做了好久菜成功的案例
• 生产者接口
  主要是以前是直接用imageIO进行输出，现在则是重新用ServletOutputStream
  要加RestController

    public void createCommonQRCode(HttpServletResponse response,
                              Long id) throws IOException {
        System.out.println("id:"+id);

        ServletOutputStream stream = null;
        try{
            SysApk sysApk = sysApkService.findById(id);
            //返回图片内容
            response.setContentType("image/jpeg");
            stream = response.getOutputStream();

            InputStream inputStream = QRCodeUtil.encode(sysApk.getApkUrl(),
                    "/usr/local/hc_logo.png",sysApk.getApkName(),stream,true);
            try {
                stream = response.getOutputStream();
                byte[] bytes = new byte[1024];
                int len = 0;
                while ((len = inputStream.read(bytes)) != -1) {
                    stream.write(bytes, 0, len);
                }
                inputStream.close();
                stream.close();
                stream.flush();
            } catch (Exception e) {

            }
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            if(stream != null){
                stream.flush();
                stream.close();
            }
        }
    }

• 消费者接口
  就如网上说的，是feign.response

@FeignClient(name = "hcnet-website-1")
public interface SysQRCodeService {
    @GetMapping(value = "/qrcode/createCommonQRCode",consumes = MediaType.APPLICATION_JSON_UTF8_VALUE)
    public Response createCommonQRCode( @RequestParam("response") HttpServletResponse response, @RequestParam("id") Long id );
}

• 消费者控制层接口
  我暂时没找到更好的方法，只能自己在服务端在输出一边

    @ApiOperation(value = "生成二维码",notes = "生成二维码")
    @ApiImplicitParams({
            @ApiImplicitParam(type = "query",name = "id",value = "ID",required = true)
    })
    @GetMapping("/qrcode/createCommonQRCode")
    @CrossOrigin(origins = "*", allowCredentials = "true",allowedHeaders = "*",methods = {RequestMethod.GET, RequestMethod.DELETE, RequestMethod.HEAD, RequestMethod.OPTIONS, RequestMethod.PUT, RequestMethod.POST, RequestMethod.PATCH})
    @ResponseBody
    public void createCommonQRCode(HttpServletResponse response1,
                              Long id) throws IOException {

        Response response = sysQRCodeService.createCommonQRCode(response1, id);
        Response.Body body = response.body();

        InputStream fileInputStream = null;
        OutputStream outStream;
        try {
            fileInputStream = body.asInputStream();
            outStream = response1.getOutputStream();

            byte[] bytes = new byte[1024];
            int len = 0;
            while ((len = fileInputStream.read(bytes)) != -1) {
                outStream.write(bytes, 0, len);
            }
            fileInputStream.close();
            outStream.close();
            outStream.flush();
        } catch (Exception e) {

        }

    }

• 顺带解决的问题BufferedImage转换为InputStream

BufferedImage image = QRCodeUtil.createImageAndFont(content, imgPath, text,needCompress);
        ByteArrayOutputStream bs = new ByteArrayOutputStream();
        //ImageIO.write(image, FORMAT_NAME, output);
        ImageIO.write(image, FORMAT_NAME, bs);
        InputStream inputStream = new ByteArrayInputStream(bs.toByteArray());

• 顺带解决的问题：Spring Boot返回二进制图片

Response response = sysQRCodeService.createCommonQRCode(response1, id);
        Response.Body body = response.body();

        InputStream fileInputStream = null;
        OutputStream outStream;
        try {
            fileInputStream = body.asInputStream();
            outStream = response1.getOutputStream();

            byte[] bytes = new byte[1024];
            int len = 0;
            while ((len = fileInputStream.read(bytes)) != -1) {
                outStream.write(bytes, 0, len);
            }
            fileInputStream.close();
            outStream.close();
            outStream.flush();
        } catch (Exception e) {

        }