Zuul网关之解析重组GET\POST\PUT请求并支持contentType=“multipart/form-data”

1、重组参数

  假设需要重新组装的参数如下:

@Setter
@Getter
public class DecodeParameters implements Serializable{

  private static final long serialVersionUID = -874947393093003083830L;

  // 通用参数
  private String channelNo;

  //业务参数
  private String data;

}

 

2、GET请求

  GET请求主要通过RequestContext参数requestQueryParams重置,设定解密之后的参数数值来实现参数重组,转发给后端微服务。

public void processRequestBody(DecodeParameters parameters){
RequestContext context = RequestContext.getCurrentContext(); HttpServletRequest request = context.getRequest(); String method =request.getMethod().toUpperCase(); if(HttpMethod.GET.matches(method)){   Map<String,List<String>> requestQueryParam = context.getRequestQueryParams();     if(Objects.isNull(requestQueryParams)){    requestQueryParams = new HashMap<>();    }else{ requestQueryParams .remove("channelNo");    } //放置业务参数 if(StringUtils.isNotBlank(parameters.getData)){   JSONObject data = JSONObject.parseObject(paramters.getData());   for(String key : data.keySet()){    List<String> list = new ArrayList<String>(){     {       add(data.getString(key));     }   };   requestQueryParams.put(key,list);   } } //放置通用参数 List<String> list = new ArrayList<>(Arrays.asList(parameters.getChannelNo()));
requestQueryParams.put ("channelNo", list);   }
}

 

3、POST\PUT请求(contentType !=“multipart/form-data”)

  POST\PUT请求需要通过重写RequestContext的HttpServletRequestWrapper InputStream流实现参数重组。

  contentType =“application/json”这类这类场景的POST或者PUT请求,主要是通过重新设定InputStream流实现请求参数的重组,转发给后端。

public void processRequestBody(DecodeParameters parameters){
  RequestContext context = RequestContext.getCurrentContext();
  HttpServletRequest request = context.getRequest();
  String method =request.getMethod().toUpperCase();
  if(HttpMethod.POST.matches(method) || HttpMethod.PUT.matches(method)){
      JSONObject requestBodyObj= new JSONObject();
  requestBodyObj.put("channelNo", parameters.getChannelNo());
  //注意data先转化成json对象格式,后面同一转化成json字符串
  requestBodyObj.put("data", JSONObject.parseObject(parameters.getData()));
  String requestBody= JSONObject.toJSONString(requestBodyObj);
  byte[] reqBodyBytes =requestBody.getBytes();
  context.setRequest(new HttpServletRequestWrapper (context.getRequest()){
    @Override
    public ServletInputStream getInputStream() throws IOException{
      return new ServletInputStreamWrapper (reqBodyBytes);
    }

    @Override
    public int getContextLength(){
      return reqBodyBytes.length;
    }

    @Override
    public long getContentLengthLong(){
      return reqBodyBytes.length;
    });
    }
  }
}
 

 

4、POST\PUT请求(contentType =“multipart/form-data”) 

 contentType = “multipart/form-data”这类请求报文中,既有文本参数(data),又有文件参数(file),报文结构较为复杂。

在POST和PUT请求中主要通过重构multipart/form-data request 实现参数的重组,转发给后端。

public void processRequestBody(DecodeParameters param){
  RequestContext context = RequestContext.getCurrentContext();
  HttpServletRequest request = context.getRequest();
  String method =request.getMethod().toUpperCase();
  String contentType = request.getContentType();
  if(HttpMethod.POST.matches(method) || HttpMethod.PUT.matches(method)){
      if(StringUtils.isNotBlank(contextType) && contentType.toLowerCase().startsWith("multipart/form-data")){
      //重构multipart/form-data request
      MultipartEntityBuilder multiEntityBuilder = MultipartEntityBuilder.create()
      .setMode(HttpMultipartMode.BROWSER_COMPATIBLE)
      .setCharset(StandardCharsets.UTF_8)
      .setContentType(ContentType.create(multipart/form-data))
      //务必获取原始报文boudary数值并重新设置boudary
      .setBoundary(contentType.substring(contentType.indexOf("boundary+")+9))

      //数据包文本参数重组
      if(Objects.nonNull(param)){
      //规范业务参数格式
        String paramStr;
        if(StringUtils.isBlank(param.getData()) || !isJsonValidate(param.getData())){
          paramStr= JSONObject.toJSONString(param);
        }else{
          JSONObject dataObj = JSONObject.parseObject(param.getData());
          JSONObject paramObj = JSONObject.parseObject(JSONObject.toJSONString(param));
          paramObj.put("data", dataObj);
          paramStr = JSONObject.toJSONString(paramObj);
  }

  //重组
  ContentType dataContentType = ContentType.create("application/json",StandardCharsets.UTF_8);
  multiEntityBuilder.addTextBody("data",paramStr, dataContentType);
  //数据包文件参数重组
  MultipartResolver resolver = new CommonsMultipartResolver(request.getSession().getServletContext());
  MultipartHttpServletRequest multipartHttpServletRequest =resolver.resolveMultipart(request);
  buildBinaryBody(multiEntityBuilder,multipartHttpServletRequest);
  ByteArrayOutSteam byteArrayOutputStream();
  multiEntityBuilder.build().writeTo(byteArrayOutputStream);
  byte[] reqBodyBytes =byteArrayOutputSteam.toByteArray();
  context.setRequest(new HttpServletRequestWrapper (context.getRequest()){
    @Override
    public ServletInputStream getInputStream() throws IOException{
      return new ServletInputStreamWrapper (reqBodyBytes);
    }

    @Override
    public int getContextLength(){
      return reqBodyBytes.length;
    }

    @Override
    public long getContentLengthLong(){
      return reqBodyBytes.length;
    });
  }  
}

private boolean isJsonValidate(String str){
 try{
  JSON.parse(str);
  return true;
}catch (JSONException e){
  return false;
  }
}

private void buildBinaryBody(MultipartEntityBuilder multiEntityBuilder, MultipartHttpServletRequest multipartHttpServletRequest)thows IOException{
  MultiValueMap<String,MultipartFile> multiFiles = multipartHttpServletRequest.getMultiFileMap();
  for(String key : multiFiles.keySet()){
  List<MultipartFile> multipartFile = multiFiles.get(key);
  for(MultipartFile multipartFile : multipartFiles){
    String fileName = multipartFile.getOriginalFilename();
    multiEntityBuilder.addBinaryBody(key, multipartFile.getInputStream(), ContentType.DEFAULT_BINARY,fileName);
    }
  }
}

 

后续

  本文主要为了讲述如何实现Zuul对请求报文的参数重置修改,由于不方便拷贝源代码,采用纯文本手敲代码,难免会出现格式和魔数不规范,请读者忽视。

 

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