[HTTPCORE-728] SSLIOSession uses SSLEngine.getApplicationProtocol() which doesn't exist in all Java 8 versions

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Not A Problem
• Affects Version/s: 5.2
• Component/s: HttpCore
• Assignee: Unassigned
• Reporter: Rob Spoor
• Created: 11/Nov/22 09:17
• Updated: 12/Nov/22 16:06
• Resolved: 11/Nov/22 13:05

Description

We have a Renovate bot that upgraded the HttpClient version from 5.1.3 to 5.2. Tests that were working before now started failing with the following message:

Exception in thread "I/O server dispatch-1" java.lang.NoSuchMethodError: javax.net.ssl.SSLEngine.getApplicationProtocol()Ljava/lang/String;
	at org.apache.hc.core5.reactor.ssl.SSLIOSession.doHandshake(SSLIOSession.java:429)

I've done a comparison between version 5.1.3 and 5.2, and this change is causing the issue:

5.1.3:

final String applicationProtocol = ReflectionUtils.callGetter(this.sslEngine, "ApplicationProtocol", String.class);

5.2:

final String applicationProtocol = this.sslEngine.getApplicationProtocol();

The cause of the issue is that this method is officially added in Java 9. From https://docs.oracle.com/en/java/javase/19/docs/api/java.base/javax/net/ssl/SSLEngine.html#getApplicationProtocol():

Since:
9

It seems that this method is backported to Java 8, but not to all versions. From https://docs.oracle.com/javase/8/docs/api/javax/net/ssl/SSLEngine.html#getApplicationProtocol--:

API Note:
This method is defined in Java SE 8 Maintenance Release 3.

One solution could be to make users upgrade Java 8 to the latest version (our build server currently uses version 1.8.0_221). However, that may not work for everybody.