配置连接池

@Autowired
    private RestTemplateBuilder restTemplateBuilder;

    /**
     * 让spring管理RestTemplate,参数相关配置
     *
     * @return
     */
    @Bean
    public RestTemplate restTemplate() {
        RestTemplate restTemplate = restTemplateBuilder.build();
        restTemplate.setRequestFactory(clientHttpRequestFactory());
        return restTemplate;
    }

    /**
     * 客户端请求链接策略
     *
     * @return
     */
    private ClientHttpRequestFactory clientHttpRequestFactory() {
        HttpComponentsClientHttpRequestFactory clientHttpRequestFactory = new HttpComponentsClientHttpRequestFactory();
        clientHttpRequestFactory.setHttpClient(httpClientBuilder().build());
        clientHttpRequestFactory.setConnectTimeout(60000);  // 连接超时时间/毫秒
        clientHttpRequestFactory.setReadTimeout(60000); // 读写超时时间/毫秒
        clientHttpRequestFactory.setConnectionRequestTimeout(50000);// 请求超时时间/毫秒
        return clientHttpRequestFactory;
    }

    /**
     * 设置HTTP连接管理器,连接池相关配置管理
     *
     * @return 客户端链接管理器
     */
    private HttpClientBuilder httpClientBuilder() {
        HttpClientBuilder httpClientBuilder = HttpClientBuilder.create();
        httpClientBuilder.setConnectionManager(poolingConnectionManager());
        ConnectionKeepAliveStrategy connectionKeepAliveStrategy = (httpResponse, httpContext) -> 20 * 1000;
        httpClientBuilder.setKeepAliveStrategy(connectionKeepAliveStrategy);
        httpClientBuilder.setRetryHandler(new DefaultHttpRequestRetryHandler());
        RequestConfig requestConfig = RequestConfig.custom()
                .setConnectTimeout(10 * 1000)
                .setSocketTimeout(10 * 1000)
                .setConnectionRequestTimeout(10 * 1000)
                .build();
        httpClientBuilder.setDefaultRequestConfig(requestConfig);
        return httpClientBuilder;
    }

    /**
     * 链接线程池管理,可以keep-alive不断开链接请求,这样速度会更快 MaxTotal 连接池最大连接数 DefaultMaxPerRoute
     * 每个主机的并发 ValidateAfterInactivity
     * 可用空闲连接过期时间,重用空闲连接时会先检查是否空闲时间超过这个时间，如果超过，释放socket重新建立
     *
     * @return
     */
    private HttpClientConnectionManager poolingConnectionManager() {
        PoolingHttpClientConnectionManager poolingConnectionManager = new PoolingHttpClientConnectionManager();
        poolingConnectionManager.setMaxTotal(1000);
        poolingConnectionManager.setDefaultMaxPerRoute(5000);
        poolingConnectionManager.setValidateAfterInactivity(30000);
        poolingConnectionManager.closeIdleConnections(30, TimeUnit.SECONDS);
        poolingConnectionManager.closeExpiredConnections();
        return poolingConnectionManager;
    }