Spring Boot RestTemplate请求出现重复Cookie头如何解决？

出现两个Cookie头的核心原因是：RestTemplate默认依赖的HttpClient库中，RequestAddCookies拦截器会自动从CookieStore中读取Cookie并添加到请求头里，和你手动设置的自定义Cookie产生冲突。以下是几种可行的解决办法：

方法一：移除RequestAddCookies拦截器 #

自定义RestTemplate时，直接从HttpClient的拦截器列表中移除这个自动添加Cookie的拦截器：

@Bean
public RestTemplate customRestTemplate() {
    HttpClientBuilder httpClientBuilder = HttpClientBuilder.create();
    
    // 过滤掉自动添加Cookie的拦截器
    List<HttpRequestInterceptor> interceptors = httpClientBuilder.getInterceptors();
    interceptors.removeIf(interceptor -> interceptor instanceof RequestAddCookies);
    
    CloseableHttpClient httpClient = httpClientBuilder.build();
    HttpComponentsClientHttpRequestFactory requestFactory = new HttpComponentsClientHttpRequestFactory(httpClient);
    
    return new RestTemplate(requestFactory);
}

方法二：禁用HttpClient的自动Cookie管理 #

直接关闭HttpClient的Cookie自动管理功能，让RequestAddCookies拦截器没有Cookie可添加：

@Bean
public RestTemplate customRestTemplate() {
    CloseableHttpClient httpClient = HttpClientBuilder.create()
            .disableCookieManagement() // 禁用自动Cookie管理
            .build();
    
    HttpComponentsClientHttpRequestFactory requestFactory = new HttpComponentsClientHttpRequestFactory(httpClient);
    return new RestTemplate(requestFactory);
}

方法三：修改已存在的默认RestTemplate配置 #

如果项目中已经使用了默认的RestTemplate实例，可以通过@PostConstruct初始化时修改其底层HttpClient配置：

@Autowired
private RestTemplate restTemplate;

@PostConstruct
public void adjustRestTemplateCookieConfig() {
    HttpComponentsClientHttpRequestFactory factory = (HttpComponentsClientHttpRequestFactory) restTemplate.getRequestFactory();
    CloseableHttpClient httpClient = (CloseableHttpClient) factory.getHttpClient();
    
    HttpClientBuilder builder = HttpClientBuilder.create().setHttpClient(httpClient);
    builder.getInterceptors().removeIf(interceptor -> interceptor instanceof RequestAddCookies);
    
    factory.setHttpClient(builder.build());
}

以上三种方法都能有效阻止HttpClient自动添加额外Cookie，之后你手动在RequestEntity中设置的自定义Cookie会成为请求中唯一的Cookie头。

内容的提问来源于stack exchange，提问作者Akash Shinde