Develop Reference

Use Java 7 Kafka client to communicate with remote Kafka broker running Java 8

Can we access Kafka installed on other machine using java7 in our system?
I have to fetch the topics by writing a consumer code but i have java7 in my system.
I know for installation we require minimum of java8.

Is there a reason you can't upgrade to Java 11 (or at least Java 8)?
Java 7 is totally unsupported and may contain unfixed security vulnerabilities.
If you still can't upgrade to at least Java 8, you will need to use a version of Kafka Clients that was compiled with Java 7. The latest such version was 1.1.1, available from the following Maven Central location:
'org.apache.kafka:kafka-clients:1.1.1'
This is an old version of Kafka Client that will be unable to take advantage of the latest features of Kafka.

How to get TLS version and applicable cipher suits from Http Request

I am using Twilio sandbox environment for testing WhatsApp integration with my application. As I moved application to different server twilio API is sending Error 20426 Upgrade Required.
Application was working fine on previous server. TLS version on both the server is 1.2 and SSL version is 3. Cipher Suits are also present on both servers as List provided in Twilio document. The only difference between two servers is the OS. On server where application is working OS installed is Linux and where application is not working OS is AIX 7.

How to connect TLS 1.2 with Java 1.4?

I need to connect with a URL but I can only connect with TLS 1.2 and the Java version available is Java 1.4. Is it possible, and if so, how to do it?

Tomcat application as a client to another server using TLSv1.2

We have a Tomcat based Infra monitoring application which will connect to other servers and monitor / alert etc.
However , some of our servers are using TLSv1.2 only and seems that the monitoring application is only using the TLSv1 to connect which is having a slight issue.
We are currently doing a workaround by using http port to mornitor but for long term we would like to use the TLSv1.2.
Is there a way to force Tomcat to connect to other applications via TLSv1.2 only?
Thanks
Using Tomcat 7 and Java 1.7.

The documentation for the SunJSSEProvider says:
Although SunJSSE in the Java SE 7 release supports TLS 1.1 and TLS
1.2, neither version is enabled by default for client connections. Some servers do not implement forward compatibility correctly and
refuse to talk to TLS 1.1 or TLS 1.2 clients. For interoperability,
SunJSSE does not enable TLS 1.1 or TLS 1.2 by default for client
connections.
So TLS 1.2 is there, it just isn't enabled. To enable it add something like
-Dhttps.protocols=TLSv1.1,TLSv1.2
to the startup-parameters of your tomcat. Then it should be able to speak TLS 1.2 as well as TLS 1.1. If you need any older protocols you can also add them as described in the linked documentation.

ActiveMQ CLIENT on Java 1.4

We are using Active MQ in the most current version 5.6.0.
Now we have the problem that a new client has to be connected, unfortunately this client is developed with IBM JDK 1.4. Adding ActiveMQ to the application lead to the following error:
UNEXPECTED ERROR OCCURRED: org/apache/activemq/ActiveMQConnectionFactory (Unsupported major.minor version 50.0)
STACK TRACE:
java.lang.UnsupportedClassVersionError: org/apache/activemq/ActiveMQConnectionFactory (Unsupported major.minor version 50.0)
We don't want to switch to an older ActiveMQ version, since there are other applications using the current version. Now my questions (I know the FAQ and especially http://activemq.apache.org/can-i-use-activemq-5x-or-later-on-java-14.html):
Are there any ActiveMQ client jars which are usable to connect to Active MQ 5.6.0?
For example is it possible to use an ActiveMQ 4.0 client to connect to Active MQ 5.6.0?
Is it possible to use any other protocol for this purpose? Has anyone a succesful solution running?
If I have to use retrotranslator which is the minimum set on jars I have to translate? Has anyone the experience with IBM JDK 1.4?
Thanks for your answers!

You can connect from STOMP to the ActiveMQ broker, or you can use an older AMQ 5.x client and connect. You can of course try an older 4.x client but its not really recommended. Version 5 clients should be able to connect without much problem however anytime you use an older client you are subject to the issues that are contained in those clients that were fixed in newer releases.

You might try to build ActiveMQ yourself (or STOMP), from source, using the -target 1.4 command line option, and addressing other cross-compile concerns. Since you have 1.4 libraries available, you should be able to use those in the bootclasspath for the cross-compile.
Cross your fingers, and you may get lucky by not having any hard dependencies on new library elements (nio). Or you might find ways to work around them.