使用 useSystemProperties() 创建 HttpClient答案

【问题标题】：create HttpClient using useSystemProperties()使用 useSystemProperties() 创建 HttpClient
【发布时间】：2019-03-27 19:34:41
【问题描述】：

我正在尝试使用 useSystemProperties() 创建一个 http 客户端，因为我需要将 ssl 属性默认为 WAS 的属性[比如在运行时获取 WAS 密码]。而且我还必须为 httpclient 设置一些最大连接数和连接管理器。这是一个非常高流量的休息电话。

我尝试了 3 种方法，

 -- This did not set the WAS ssl properties and thus the connection got failed.
httpclient = HttpClients.custom().useSystemProperties()
                        .setConnectionManager("some value")
                        .setMaxConnPerRoute("some value")
                        .setMaxConnTotal("some value")
                        .setUserAgent("Custom Browser")
                        .disableCookieManagement().build();

 -- This did not set the WAS ssl properties and thus the connection failed.
httpclient1 = HttpClientBuilder.create().useSystemProperties()
                               .setConnectionManager(connManager)
                               .setMaxConnPerRoute(maxConnPerRoute)
                               .setMaxConnTotal(maxConnTotal)
                               .setUserAgent("Custom Browser")
                               .disableCookieManagement().build();

-- This one defaulted to WAS ssl configurations and connection was fine but other params are missing here.
httpclient2 = HttpClientBuilder.create().useSystemProperties().build();

我真的可以同时实现这两个选项吗？

【问题讨论】：

标签： java apache http httpclient

【解决方案1】：

您需要为您的ConnectionManager 覆盖SSLConnectionSocketFactory，例如，如果您使用useSystemProperties，下面的示例将创建默认SSLConnectionSocketFactory

    DefaultHostnameVerifier hostnameVerifier = new DefaultHostnameVerifier(PublicSuffixMatcherLoader.getDefault());
    SSLConnectionSocketFactory sslConnectionSocketFactory = new SSLConnectionSocketFactory(
            (SSLSocketFactory) SSLSocketFactory.getDefault(), null, null, hostnameVerifier
    );

    final PoolingHttpClientConnectionManager connManager = new PoolingHttpClientConnectionManager(
            RegistryBuilder.<ConnectionSocketFactory>create()
                    .register("http", PlainConnectionSocketFactory.getSocketFactory())
                    .register("https", sslConnectionSocketFactory)
                    .build()
    );

    connManager.setDefaultMaxPerRoute(20);
    connManager.setMaxTotal(20);


    final HttpClientBuilder builder = HttpClientBuilder
            .create()
            .setConnectionManager(connManager);

【讨论】：

【解决方案2】：

您也可以将useSystemProperties() 设置为您的HttpClient：

HttpClient httpClient = HttpClientBuilder.create()
            .setConnectionManager(connectionManager)
            .useSystemProperties()
            .setDefaultRequestConfig(requestConfig).build();

【讨论】：