RestTemplate使用httpClient连接池

说明

RestTemplate是Spring提供的用于访问Rest服务的客户端，可以通过ClientHttpRequestFactory创建。默认采用的是SimpleClientHttpRequestFactory，底层是HttpURLConnection（java.net包提供的方式），不具备连接池的功能，默认超时为-1。可以引入httpClient连接池

使用

• 添加依赖

 <dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpclient</artifactId>
    <version>4.5.13</version> <!-- 版本号可能会不同，根据实际情况选择 -->
</dependency>

• 配置

@Configuration
public class RestTemplateConfig {
    @Bean
    public RestTemplate restTemplate() {
        ClientHttpRequestFactory factory = new HttpComponentsClientHttpRequestFactory(httpClient());
        return new RestTemplate(factory);
    }

    private CloseableHttpClient httpClient() {
        Registry<ConnectionSocketFactory> registry = RegistryBuilder.<ConnectionSocketFactory>create()
                .register("http", PlainConnectionSocketFactory.getSocketFactory())
                .register("https", SSLConnectionSocketFactory.getSocketFactory())
                .build();
        PoolingHttpClientConnectionManager connectionManager = new PoolingHttpClientConnectionManager(registry);
        connectionManager.setMaxTotal(50);
        connectionManager.setDefaultMaxPerRoute(50);
        RequestConfig requestConfig = RequestConfig.custom()
                .setSocketTimeout(30000)
                .setConnectTimeout(10000)
                .setConnectionRequestTimeout(10000)
                .build();
        return HttpClientBuilder.create()
                .setDefaultRequestConfig(requestConfig)
                .setConnectionManager(connectionManager)
                .build();
    }
}