初始化编辑

可以通过相应的 RestClientBuilder 类构建 RestClient 实例,该类通过 RestClient#builder(HttpHost...) 静态方法创建。 唯一需要的参数是客户端将与之通信的一个或多个主机,作为 HttpHost 的实例提供,如下所示

RestClient restClient = RestClient.builder(
    new HttpHost("localhost", 9200, "http"),
    new HttpHost("localhost", 9201, "http")).build();

RestClient 类是线程安全的,理想情况下与其使用的应用程序具有相同的生命周期。 当不再需要它时,关闭它很重要,以便正确释放它使用的所有资源,以及底层 http 客户端实例及其线程

restClient.close();

RestClientBuilder 还允许在构建 RestClient 实例时选择性地设置以下配置参数

RestClientBuilder builder = RestClient.builder(
    new HttpHost("localhost", 9200, "http"));
Header[] defaultHeaders = new Header[]{new BasicHeader("header", "value")};
builder.setDefaultHeaders(defaultHeaders); 

设置每次请求需要发送的默认标头,以防止每次请求都必须指定它们

RestClientBuilder builder = RestClient.builder(
        new HttpHost("localhost", 9200, "http"));
builder.setFailureListener(new RestClient.FailureListener() {
    @Override
    public void onFailure(Node node) {
        
    }
});

设置一个监听器,在节点发生故障时收到通知,以防需要采取措施。 在启用故障嗅探时在内部使用。

RestClientBuilder builder = RestClient.builder(
    new HttpHost("localhost", 9200, "http"));
builder.setNodeSelector(NodeSelector.SKIP_DEDICATED_MASTERS); 

设置节点选择器,用于过滤客户端将在设置给客户端本身的节点中发送请求的节点。 例如,当启用嗅探时,这对于防止向专用主节点发送请求非常有用。 默认情况下,客户端向每个配置的节点发送请求。

RestClientBuilder builder = RestClient.builder(
        new HttpHost("localhost", 9200, "http"));
builder.setRequestConfigCallback(
    new RestClientBuilder.RequestConfigCallback() {
        @Override
        public RequestConfig.Builder customizeRequestConfig(
                RequestConfig.Builder requestConfigBuilder) {
            return requestConfigBuilder.setSocketTimeout(10000); 
        }
    });

设置一个回调,允许修改默认请求配置(例如请求超时、身份验证或 org.apache.http.client.config.RequestConfig.Builder 允许设置的任何内容)

RestClientBuilder builder = RestClient.builder(
    new HttpHost("localhost", 9200, "http"));
builder.setHttpClientConfigCallback(new HttpClientConfigCallback() {
        @Override
        public HttpAsyncClientBuilder customizeHttpClient(
                HttpAsyncClientBuilder httpClientBuilder) {
            return httpClientBuilder.setProxy(
                new HttpHost("proxy", 9000, "http"));  
        }
    });

设置一个回调,允许修改 http 客户端配置(例如,通过 ssl 进行加密通信,或 org.apache.http.impl.nio.client.HttpAsyncClientBuilder 允许设置的任何内容)