java - 使用HttpComponentsClientHttpRequestFactory在RestTemplateBuilder中添加自定义ClientHttpRequestInterceptor

我需要在所有RestTemplate客户端请求中添加自定义标题。因此我实现了ClientHttpRequestInterceptor。然后将拦截器添加到我的RestTemplateBuilder配置中，如下所示。问题是，当RestTemplate进行HTTP调用时，它将引发以下异常：

java.lang.ClassCastException: org.springframework.http.client.InterceptingClientHttpRequestFactory cannot be cast to org.springframework.http.client.HttpComponentsClientHttpRequestFactory

RestTemplate Bean创建：

@Bean
  public RestTemplate restTemplate(RestTemplateBuilder restTemplateBuilder) {
    PoolingHttpClientConnectionManager poolingConnectionManager = new PoolingHttpClientConnectionManager();
    poolingConnectionManager.setMaxTotal(restTemplateProps.getMaxConnectionsPerPool());
    poolingConnectionManager.setDefaultMaxPerRoute(restTemplateProps.getMaxDefaultConnectionPerRoute());
    CloseableHttpClient client = HttpClientBuilder.create().setConnectionManager(poolingConnectionManager).build();
    ClientHttpRequestFactory clientHttpRequestFactory = new HttpComponentsClientHttpRequestFactory(client);
    restTemplateBuilder = restTemplateBuilder.additionalInterceptors(new MyClientHttpRequestInterceptor());
    return restTemplateBuilder.requestFactory(clientHttpRequestFactory).build();
  }

另外，我稍后在下面的代码中更新超时：

  protected void setRestTemplateTimeouts() {

    HttpComponentsClientHttpRequestFactory rf =
        (HttpComponentsClientHttpRequestFactory) restTemplate.getRequestFactory();
    rf.setConnectTimeout(restTemplateProps.getConnectionTimeout());
    rf.setReadTimeout(restTemplateProps.getSocketTimeout());
  }

谁能帮我解决这个问题？

最佳答案

问题是，我试图在设置ClientHttpRequestInterceptor后设置连接和读取超时。

在我的setRestTemplateTimeouts()方法中，当我尝试获取requestFactory并将其转换为HttpComponentsClientHttpRequestFactory时，出现了ClassCastException异常，因为restTemplate.getRequestFactory()返回了InterceptingClientHttpRequestFactory而不是HttpComponentsClientHttpRequestFactory。这是因为我在restTemplate对象中添加了一个拦截器。

解决方案是在设置拦截器之前设置超时，因为在设置拦截器之后无法设置超时。请参考以下代码：

@Bean
  public RestTemplate restTemplate(RestTemplateBuilder restTemplateBuilder) {
    PoolingHttpClientConnectionManager poolingConnectionManager = new PoolingHttpClientConnectionManager();
    poolingConnectionManager.setMaxTotal(restTemplateProps.getMaxConnectionsPerPool());
    poolingConnectionManager.setDefaultMaxPerRoute(restTemplateProps.getMaxDefaultConnectionPerRoute());
    CloseableHttpClient client = HttpClientBuilder.create().setConnectionManager(poolingConnectionManager).build();
    HttpComponentsClientHttpRequestFactory clientHttpRequestFactory = new HttpComponentsClientHttpRequestFactory(client);
    clientHttpRequestFactory.setConnectTimeout(restTemplateProps.getConnectionTimeout());
    clientHttpRequestFactory.setReadTimeout(restTemplateProps.getSocketTimeout());
    restTemplateBuilder = restTemplateBuilder.additionalInterceptors(new MyClientHttpRequestInterceptor());
    return restTemplateBuilder.requestFactory(clientHttpRequestFactory).build();
  }