Connection is not stable (wrong detection if SSL context is configured)

[pj892031]

The class org.glassfish.jersey.client.internal.HttpUrlConnector contains this code.

    private static final LazyValue<SSLSocketFactory> DEFAULT_SSL_SOCKET_FACTORY =
            Values.lazy((Value<SSLSocketFactory>) () -> HttpsURLConnection.getDefaultSSLSocketFactory());

https://github.com/eclipse-ee4j/jersey/blame/d377a30a033cb7468d66e9901ee832bea6cbd8db/core-client/src/main/java/org/glassfish/jersey/client/internal/HttpUrlConnector.java#L86-L87

            if (DEFAULT_SSL_SOCKET_FACTORY.get() == suc.getSSLSocketFactory()) {
                // indicates that the custom socket factory was not set
                suc.setSSLSocketFactory(sslSocketFactory.get());
            }

https://github.com/eclipse-ee4j/jersey/blame/d377a30a033cb7468d66e9901ee832bea6cbd8db/core-client/src/main/java/org/glassfish/jersey/client/internal/HttpUrlConnector.java#L316-L319

It has a relationship with the default constructor of class javax.net.ssl.HttpsURLConnection

    protected HttpsURLConnection(URL url) {
        super(url);
        this.hostnameVerifier = defaultHostnameVerifier;
        this.sslSocketFactory = getDefaultSSLSocketFactory();
    }

The idea of this code is to detect if the connection has set an extra SSL Context or if it was not defined. There is one potential issue, once some other code changes the default configuration (HttpsURLConnection.getDefaultSSLSocketFactory(<new context>)) the condition stops working. The SSL context is never set and it uses the default one. It means once the user sets a context and then changes the default context for any reason the connection starts using the default one. Keep in mind, that it could also leverage the connection (ie. adding a client certificate to a connection could change behavior, trust store is changed, etc.).

The proper solution should be just to set the SSL context provided by a client (HttpsURLConnection.getDefaultSSLSocketFactory()). The current behavior does not make any sense. If the user configures an SSLContext, it should be used, otherwise, the default one is expected (it means without the settings).

[jansupol]

Relates to #4815. The problem is a bug in the JDK that never gets fixed. The workaround is problematic as there are multiple requests each going against the other.