[Java] 解决使用RestTemplate时报错RestClientException的问题

• 使用RestTemplate时报错RestClientException
  
  
  
  • 这是自己封装的一个发送请求的方法
    
  • 这是自定义的一个http信息Converter
    
  
  
• RestTemplate的错误处理
  
  
  
  • 问题描述
    
  • ErrorHandler
    
  • 解决办法
    
  
  

public  Map<String, Object> sendRequest(Map<String, Object> body,String sessionId,String url) {
    RestTemplate restTemplate = new RestTemplate();
    restTemplate.getMessageConverters().add(new BdMappingJackson2HttpMessageConverter());
    Map<String, Object> map = new HashMap<>();
    try {
      ParameterizedTypeReference<Map<String, Object>> typeRef = new ParameterizedTypeReference<Map<String, Object>>() {
      };
      HttpHeaders headers = new HttpHeaders();
      headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
      headers.set("cookie", "SESSION="+sessionId);
      HttpEntity<Map<String, Object>> requestEntity = new HttpEntity<>(body,headers);
      ResponseEntity<Map<String, Object>> responseEntity = restTemplate.exchange(url, HttpMethod.POST,
          requestEntity,typeRef);
      map = responseEntity.getBody();
      log.info(map.toString());
    } catch (HttpStatusCodeException e) {
      log.error(e.getResponseBodyAsString(), e);
      map = JsonUtil.toMap(e.getResponseBodyAsString());
    }
    return map;
  }

public class BdMappingJackson2HttpMessageConverter extends MappingJackson2HttpMessageConverter {
  public BdMappingJackson2HttpMessageConverter(){
    List<MediaType> mediaTypes = new ArrayList<>();
    mediaTypes.add(MediaType.TEXT_HTML);
    mediaTypes.add(MediaType.APPLICATION_OCTET_STREAM);
    setSupportedMediaTypes(mediaTypes);
  }
}

Could not write request: no suitable HttpMessageConverter found for request type [java.util.HashMap] and content type [application/octet-stream]

Could not extract response: no suitable HttpMessageConverter found for response type [java.util.Map<java.lang.String, java.lang.Object>] and content type [text/xml;charset=UTF-8]

• text/html:HTML格式
  
• text/plain:纯文本格式
  
• image/png:png图片格式
  
• application/json:JSON数据格式
  
• application/octet-stream:二进制流数据
  
• application/x-www-form-urlencoded:表单中默认的encType,表单数据被编码为key/value格式发送到服务器
  
• multipart/form-data:需要在表单中进行文件上传时，就需要使用该格式
  

public interface ResponseErrorHandler {
  boolean hasError(ClientHttpResponse var1) throws IOException;
  void handleError(ClientHttpResponse var1) throws IOException;
}

protected boolean hasError(HttpStatus statusCode) {
    return statusCode.series() == Series.CLIENT_ERROR || statusCode.series() == Series.SERVER_ERROR;
  }

public void handleError(ClientHttpResponse response) throws IOException {
    HttpStatus statusCode = this.getHttpStatusCode(response);
    switch(null.$SwitchMap$org$springframework$http$HttpStatus$Series[statusCode.series().ordinal()]) {
    case 1:
      throw new HttpClientErrorException(statusCode, response.getStatusText(), response.getHeaders(), this.getResponseBody(response), this.getCharset(response));
    case 2:
      throw new HttpServerErrorException(statusCode, response.getStatusText(), response.getHeaders(), this.getResponseBody(response), this.getCharset(response));
    default:
      throw new RestClientException("Unknown status code [" + statusCode + "]");
    }
  }