使用HttpClient实现跨服务图片下载

以你之姓@ 2021-09-27 16:42 246阅读 0赞

需求：

由于web系统存放图片的文件夹路径和erp系统存放图片的文件夹路径不一样

所以

web系统文件上传的文件要拷贝到erp对应的文件夹

思路：

在erp中访问图片接口的时候，如果图片不存在，则调web系统的访问图片接口，把图片保存到erp指定的文件夹

ERP代码：

@RequestMapping(value = \{ "/viewImg2/\{fileName:.+\}" \})  
  public void viewImg(@PathVariable String fileName, final HttpServletResponse request,  
      final HttpServletResponse response) throws Exception \{  
    String ext = StringUtils.substringAfterLast(fileName, ".");  
    String pre = StringUtils.substringBeforeLast(fileName, ".");  
    String path = saveFilePath + "\\\\" + fileName;

logger.debug(path);  
    File file = new File(path);  
    if (!file.exists()) \{  
      // 获取web系统上传的图片  
      CloseableHttpClient httpClient = HttpClients.createDefault();  
      String\[\] arrayStr = fileName.split("\\\\.");  
      String url = remotePath + "/api/upload/viewImg/" + arrayStr\[1\] + "/" + arrayStr\[0\];  
      HttpGet httpGet = new HttpGet(url);  
      httpGet.setHeader("token", remoteToken);  
      // 设置超时时间  
      RequestConfig requestConfig = RequestConfig.custom().setSocketTimeout(60000).setConnectTimeout(50000).build();  
      httpGet.setConfig(requestConfig);  
      CloseableHttpResponse res = httpClient.execute(httpGet);  
      if (res.getStatusLine().getStatusCode() == 200) \{  
        // 得到实体  
        HttpEntity entity = res.getEntity();  
        byte\[\] data = EntityUtils.toByteArray(entity);  
        // 图片存入磁盘  
        FileOutputStream fos = new FileOutputStream(path);//path为完整路径  
        fos.write(data);  
        fos.close();  
        httpClient.close();  
      \} else \{  
        return;  
      \}

if (file.length() > 1024 \* 1024 \* 2) \{ // 大于1M,缩小50%  
      File tmpFile = new File(saveFilePath + "\\\\" + pre + "-scale." + ext);  
      if (!tmpFile.exists()) \{  
        Thumbnails.of(file).scale(0.5).toFile(tmpFile);  
        file = new File(saveFilePath + "\\\\" + pre + "-scale." + ext);  
      \} else \{  
        file = tmpFile;  
      \}  
    \}  
    BufferedInputStream br = new BufferedInputStream(new FileInputStream(file));  
    byte\[\] buf = new byte\[1024\];  
    int len = 0;  
    response.reset(); // 非常重要  
    if ("gif".equalsIgnoreCase(ext)) \{  
      response.setContentType(GIF);  
    \} else if ("bmp".equalsIgnoreCase(ext)) \{  
      response.setContentType(BMP);  
    \} else if ("png".equalsIgnoreCase(ext)) \{  
      response.setContentType(PNG);  
    \} else \{  
      response.setContentType(JPG);  
    \}  
    OutputStream out = response.getOutputStream();  
    while ((len = br.read(buf)) > 0) \{  
      out.write(buf, 0, len);  
    \}  
    br.close();  
    out.close();  
  \}

web系统代码：

@RequestMapping(value = \{ "/viewImg/\{ext\}/\{fileName\}" \})  
  public void viewImg(@PathVariable String fileName, @PathVariable String ext, final HttpServletResponse request,  
      final HttpServletResponse response) throws Exception \{  
    if (StringUtils.isNotEmpty(ext)) \{  
      fileName += "." + ext;  
    \}  
    String path = saveFilePath + "\\\\" + fileName;  
    logger.debug(path);  
    File file = new File(path);  
    if (!file.exists()) \{  
      return;  
    \}

response.reset(); // 非常重要  
    if ("gif".equalsIgnoreCase(ext)) \{  
      response.setContentType(GIF);  
    \} else if ("bmp".equalsIgnoreCase(ext)) \{  
      response.setContentType(BMP);  
    \} else if ("png".equalsIgnoreCase(ext)) \{  
      response.setContentType(PNG);  
    \} else \{  
      response.setContentType(JPG);  
    \}  
    OutputStream out = response.getOutputStream();  
    IOUtils.write(FileUtils.readFileToByteArray(file), out);  
  \}

总结：

1.调其他项目的接口时，要把文件放到api文件夹中

2.调用web的接口的时候，要在请求头中加token