java - 使用 SSL 时 Apache HttpClient 抛出 SocketTimeoutException

Question

我正在使用 Apache httpclient 4.3.6 和 httpcore 4.3.3(与 opensaml 3.3.0 捆绑在一起)。我尝试通过 HTTPS 通过代理获取网页，但每次都会收到 SocketTimeoutException。 HTTP 连接工作正常。具体的超时时间并不重要；更高的值只是需要更长的时间才能失败。

示例代码:

public class TestGet {
    private static final int TIMEOUT = 7000;

    public static void main(String[] args) throws Exception {
        URL url   = new URL("https://www.google.com");
        URL proxy = new URL("https://myproxy:9090/");
        try {
            String s = get(url, proxy);
            System.out.println(s);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private static String get(URL url, URL proxy) throws IOException, URISyntaxException {
        CloseableHttpClient client  = HttpClients.createDefault();
        HttpGet             request = new HttpGet(url.toURI());
        HttpHost            host    = null;

        if (proxy != null) {
            host = new HttpHost(proxy.getHost(), proxy.getPort(), proxy.getProtocol());
        }

        RequestConfig config = RequestConfig.custom()
            .setProxy(host)
            .setConnectionRequestTimeout(TIMEOUT)
            .setConnectTimeout(TIMEOUT)
            .setSocketTimeout(TIMEOUT)
            .build();
        request.setConfig(config);

        try {
            CloseableHttpResponse response = client.execute(request);
            try {
                System.out.println(response.getStatusLine());
                return EntityUtils.toString(response.getEntity());
            } finally {
                response.close();
            }
        } finally {
            client.close();
        }
    }
}

尝试连接到代理时抛出异常。堆栈跟踪是

org.apache.http.conn.ConnectTimeoutException: Connect to <proxy> failed: Read 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:371)
    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 authentication.TestGet.get(TestGet.java:47)
    at authentication.TestGet.main(TestGet.java:22)
Caused by: java.net.SocketTimeoutException: Read timed out
    at java.net.SocketInputStream.socketRead0(Native Method)
    at java.net.SocketInputStream.socketRead(Unknown Source)
    at java.net.SocketInputStream.read(Unknown Source)
    at java.net.SocketInputStream.read(Unknown Source)
    at sun.security.ssl.InputRecord.readFully(Unknown Source)
    at sun.security.ssl.InputRecord.read(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.readRecord(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.performInitialHandshake(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
    at org.apache.http.conn.ssl.SSLConnectionSocketFactory.createLayeredSocket(SSLConnectionSocketFactory.java:290)
    at org.apache.http.conn.ssl.SSLConnectionSocketFactory.connectSocket(SSLConnectionSocketFactory.java:259)
    at org.apache.http.impl.conn.HttpClientConnectionOperator.connect(HttpClientConnectionOperator.java:125)
    ... 11 more

这看起来很像 Apache 问题 HTTPCLIENT-1478这与未设置套接字超时有关。该错误已在 4.3.4 中标记为修复(我正在使用 4.3.6)，虽然一些评论表明在更高版本中仍然需要解决方法，但它们对我不起作用。更重要的是，我已经进入 SSLConnectionSocketFactory.createConnection() 并确认套接字超时设置为非零值。

我被困住了。我不知道为什么连接失败，并且无法比调用 SSLSocketImpl.startHandshake() 更深入地进行故障排除。可能出了什么问题，如何解决？

Answer 1

不要使用.setConnectionRequestTimeout(TIMEOUT)

或者，等待很长时间，看看会发生什么。

阅读this了解更多信息。