我正在我的java应用程序上设置google captcha，我得到连接超时：

Caused by: org.apache.http.conn.ConnectTimeoutException: Connect to www.google.com:443 [www.google.com/172.217.168.164] failed: connect timed out
    at org.apache.http.impl.conn.HttpClientConnectionOperator.connect(HttpClientConnectionOperator.java:134)
    at org.apache.http.impl.conn.PoolingHttpClientConnectionManager.connect(PoolingHttpClientConnectionManager.java:319)
    at org.apache.http.impl.execchain.MainClientExec.establishRoute(MainClientExec.java:363)
    at org.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.java:219)
    at org.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:195)
    at org.apache.http.impl.execchain.RetryExec.execute(RetryExec.java:86)
    at org.apache.http.impl.execchain.RedirectExec.execute(RedirectExec.java:108)
    at org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:184)
    at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:82)
    at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:106)
    at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:57)
    at com.mashape.unirest.http.HttpClientHelper.request(HttpClientHelper.java:138)
HttpClientHelper.java:138
    ... 2 more
Caused by: java.net.SocketTimeoutException: connect timed out
    at java.net.DualStackPlainSocketImpl.waitForConnect(Native Method)
    at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:85)
    at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
    at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
    at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
    at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172)
    at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
    at java.net.Socket.connect(Socket.java:589)
    at org.apache.http.conn.ssl.SSLConnectionSocketFactory.connectSocket(SSLConnectionSocketFactory.java:244)
    at org.apache.http.impl.conn.HttpClientConnectionOperator.connect(HttpClientConnectionOperator.java:1

为了测试网络是否有问题，我用Postman和cURL发出了同样的请求，都返回了预期的响应，然后我用Postman生成java代码，运行它，得到了同样的错误。
请注意，为了使请求与Postman一起工作，我必须关闭“使用系统代理”。这使我想到，也许java默认使用系统代理，并试图用System.setProperty("java.net.useSystemProxies", "false");禁用它（也尝试了true）。仍然得到相同的错误。
下面是使用的代码示例：

HttpResponse<String> response = Unirest.post("https://www.google.com/recaptcha/api/siteverify")
        .header("response", "abc")
        .header("secret", "abc")
        .asString();

先谢谢你。