直接上代码

//ES地址https://cs-test.com/es
List<HttpHost> httpHosts = new ArrayList<>();
httpHosts.add(HttpHost.create("https://cs-test.com/"));
ElasticsearchSink.Builder<Object> esSink = new ElasticsearchSink.Builder<>(httpHosts,new ESSinkFunction<>());
esSink.setRestClientFactory(new DevRestClientFactory());


//实现RestClientFactory接口
static class DevRestClientFactory implements RestClientFactory{
    @Override
    public void configureRestClientBuilder(RestClientBuilder restClientBuilder) {
        //域名后的地址
        restClientBuilder.setPathPrefix("es");
    }
}