使用HttpClientMultipartEntityBuilder上传文件，并解决中文文。。。

⽂。。。

遇到⼀种业务场景，前端上传的⽂件需要经过java服务转发⾄⽂件服务。期间遇到了原⽣HttpClient怎么使⽤的问题、怎么把MultipartFile怎么重新组装成Http请求发送出去的问题、⽂件中⽂名乱码问题。最后都解决了，先上代码，再讲遇到的坑

1 @Slf4j 2 @Service

3 public class FileServiceImpl implements IFileService { 4

5 @Value(\"${FileService.putUrl}\") 6 private String putUrl;

7 @Value(\"${FileService.app_id}\") 8 private String appId;

9 @Value(\"${FileService.securityKey}\")10 private String secureKey;11

12 private final static String UPLOAD_RESPONSE_CODE = \"error\";13 private final static Integer UPLOAD_RESPONSE_SUCCESS = 0;14 15

16 @Override

17 public String upload(MultipartFile file) {18

19 int timeOut = 30000;

20 CloseableHttpClient httpClient = HttpClientBuilder.create().build();

21 HttpHost proxy = new HttpHost(\"127.0.0.1\//设置本地fiddler代理，⽅便排查问题22 RequestConfig requestConfig = RequestConfig.custom().setConnectionRequestTimeout(timeOut)23 .setConnectTimeout(timeOut).setSocketTimeout(timeOut).setProxy(proxy).build();24 HttpPost httpPost = new HttpPost(putUrl);25 httpPost.setConfig(requestConfig);26 try {

27 //BROWSER_COMPATIBLE⾃定义charset，RFC6532=utf-8，STRICT=iso-8859-1

28 //此处⼀定要⽤RFC6532，⽹上普遍⽤的BROWSER_COMPATIBLE依然会出现中⽂名乱码

29 MultipartEntityBuilder multipartEntityBuilder = MultipartEntityBuilder.create().setMode(HttpMultipartMode.RFC6532);30 //multipartEntityBuilder.setCharset(Charset.forName(\"UTF-8\")); //此处踩坑，转发出去的filename依然为乱码

31 //ContentType contentType = ContentType.create(\"multipart/form-data\此处也是坑，转发出去的filename依然为乱码32 multipartEntityBuilder.addBinaryBody(\"file\33

34 multipartEntityBuilder.addTextBody(\"app_id\//可替换成你⾃⼰需要的附加字段35 long time = System.currentTimeMillis() / 1000;

36 multipartEntityBuilder.addTextBody(\"time\//可替换成你⾃⼰需要的附加字段37 String beforeSign = String.format(\"app_id=%s&time=%s%s\38 String sign = MD5Util.md5(beforeSign);

39 multipartEntityBuilder.addTextBody(\"sign\//可替换成你⾃⼰需要的附加字段40

41 HttpEntity requestEntity = multipartEntityBuilder.build();42 httpPost.setEntity(requestEntity);

43 HttpResponse httpResponse = httpClient.execute(httpPost);44 int statusCode= httpResponse.getStatusLine().getStatusCode();

45 if (statusCode != 200) throw new BizException(BizCode.INNER_SERVICE_ERROR, \"响应状态码为：\" + statusCode);46 HttpEntity responseEntity = httpResponse.getEntity();47 return getUrlString(EntityUtils.toString(responseEntity));48 } catch (Exception e) {

49 log.error(\"发送⽂件异常：{}\

50 throw new BizException(BizCode.INNER_SERVICE_ERROR, \"发送⽂件服务异常:\" + e.getMessage());51 } finally {52 try {

53 httpClient.close(); } catch (IOException e) {

55 log.error(\"关闭httpClient异常：\" + e.getMessage(), e);56 }57 }58 }59

60 private String getUrlString(String jsonString) {61 try{

62 log.debug(\"解析json串：\"+ jsonString);

63 JSONObject jsonObject = JSONObject.parseObject(jsonString);

if (jsonObject.getInteger(UPLOAD_RESPONSE_CODE) != UPLOAD_RESPONSE_SUCCESS) {65 log.error(\"⽂件服务返回错误：\" + jsonObject.getString(\"data\"));

66 throw new OtherServiceReturnErrorException(\"⽂件服务返回错误：\" + jsonObject.getString(\"data\"));67 }

68 return ((JSONObject)jsonObject.get(\"data\")).get(\"original\").toString();69 }catch (Exception e) {

70 log.error(\"⽂件服务返回json解析错误：\" + jsonString);

71 throw new OtherServiceReturnErrorException(\"⽂件服务返回json解析错误：\" + jsonString);72 }73 74 }

75 }

特别说明及遇到的坑：

1. 这⾥基于tomcat进⾏请求转发，需要在代码中⼿动添加代理：

HttpHost proxy = new HttpHost(\"127.0.0.1\//设置本地fiddler代理，⽅便排查问题RequestConfig requestConfig = RequestConfig.custom().setConnectionRequestTimeout(timeOut) .setConnectTimeout(timeOut).setSocketTimeout(timeOut).setProxy(proxy).build();

2. MultipartFile通过getInputStream()可以将流设置到MultipartEntityBuilder中，其中addBinaryBody⾥⾯的ContentType 和 filename必须设置，要不然后续服务读取不到这个⽂件流

MultipartEntityBuilder multipartEntityBuilder = MultipartEntityBuilder.create().setMode(HttpMultipartMode.RFC6532);

multipartEntityBuilder.addBinaryBody(\"file\ContentType.DEFAULT_BINARY, file.getOriginalFilename());3. file.getOriginalFilename()⽅法虽然没有乱码，但是addBinaryBody后，组装的Http请求出去总是乱码，如下图：

踩了各种坑，如为MultipartEntityBuilder设置Charset或者是⼿动设置ContentType，都⽆法解决此问题，⽂件名依然是上图所⽰乱码后来发现在MultipartEntityBuilder中设置Mode为HttpMultipartMode.RFC6532可以完美解决这个问题，并且不再需要单独设置ContentType或Charset，因为HttpMultipartMode.RFC6532就告诉了MultipartEntityBuilder，⾥⾯的数据都要使⽤UTF-8进⾏处理，fiddler抓到的请求发现filename成功变成中⽂名。 done