Rony discussed the use of Java for creating graphical user interfaces (GUIs), highlighting its benefits such as operating system independence. He detailed the challenges Java programmers faced in developing GUI classes that could work across all operating systems and how they overcame these hurdles. Rony also explained the technical aspects of GUIs, including the representation of pixels, the increase in screen resolution over time, and the role of specialized graphical processors in modern personal computers.

Rony provided an in-depth explanation of Java's GUI classes and their components, emphasizing the importance of understanding their functionalities and hierarchical structure. He discussed the evolution of these classes, from the original Greek classes to the introduction of Swing, and highlighted the benefits and drawbacks of each generation. Rony also touched on the concept of events in Java GUI components, the use of event listeners, and the challenges of maintaining the positions of GUI components during window resizing. Lastly, he demonstrated a simple Java program using GUI components and compared it to a similar program in Recs, aiming to show that such programs could be created without extensive Java programming skills.

Rony provided a comprehensive introduction to Java programming, covering topics such as the import statement, class definition, and the main method. He also explained the concept of a GUI and demonstrated the creation of a simple GUI frame. Rony further discussed the origin and symbolism of the Java programming language and demonstrated how to compile and run a simple Java program. He also identified an issue with the program's closure, which remained an open question for the team.

Rony explained the concept of event handling in Java, emphasizing the importance of implementing all event methods and the use of event adapter classes to save coding time. He also discussed the principles of GUI programming in Java, including the creation and handling of events, and the role of the AWT thread in maintaining the GUI. A problem with the current Rex program that uses the Java GUI system was identified, where the GUI shuts down immediately when the program ends. Rony proposed a solution to synchronize the main Rex program with the state of the GUI and stressed the importance of understanding the problem before implementing the solution.

Rony discussed the implementation of Rexx event handling in Java and the creation of a simple GUI using Java's Abstract Window Toolkit (AWT) classes. He emphasized the importance of defining proper orex classes for event handling, using adapter classes to handle multiple event methods efficiently, and the consideration of selecting appropriate AWT classes and identifying events of interest. Rony also demonstrated the compiled program and its reactions to user input, and highlighted the necessity of defining Rec classes for each use and the need to synchronize the main Rex program with the GUI part. He further discussed the implementation of various Rex classes in a Java program, the functionality of the Regs class, and its methods.

Rony discussed the functionality and benefits of a program that runs unchanged on various operating systems, including Windows, Apple, and Linux. He emphasized that the program, written in Rexx, does not require knowledge of Java syntax and can be used to implement Java methods. Rony also highlighted that the program's GUI behaves like a Java solution and that it's possible to create Rexx objects that implement Java interface classes. He provided some helpful links for further technical details and encouraged the attendees to explore the GUI examples.

Rony explained the fundamental concept of socket programming, using the analogy of a switchboard to illustrate how programs communicate with each other. He detailed the function of TCP/IP sockets as a switchboard with 65,536 ports, each numbered from 0 to 65,535, and highlighted the significance of each computer having a unique IP address. Rony also introduced IP version 6 addresses, which offer a much larger number range than IP version 4 addresses due to their 128-bit values.

Rony discussed the use of Java for client-server programming via sockets, focusing on the concepts of Internet addresses and domain names. He explained the limitations of Internet addresses and introduced the name service program that allows computers to be identified using human-memorable names. Rony also delved into the development of domain names, their commercialization, and their role in locating computers. He demonstrated a Java program, 'Gethostinfo', which uses the Java class to fetch an Internet address based on user input and emphasized the importance of the 'try-catch' block for handling exceptions. Lastly, he introduced the 'java.net.Socket' class for connecting to a computer via the Internet, requiring the IP address, host name, and port number.

Rony explained the functionalities of the Java socket class and its role in establishing connections between computers. He detailed the processes involved in creating a client-server program, emphasizing the importance of clear communication protocols and the use of port numbers. Rony also demonstrated the implementation of a simple server and client program using Java and Rexx, illustrating how data is exchanged using byte arrays and specific Java classes. The program was run live to show its efficiency.

Rony demonstrated the communication capabilities between a Java socket server and a Rex client, confirming that they could function independently of each other's programming language. He emphasized the importance of data encryption to prevent eavesdropping, explaining that the standard solution is to use the Transport Layer Security (TLS) protocol. Rony also highlighted that Java offers built-in TLS support, which is not available in Rex. He advised the team to be aware of potential security risks when using socket connections and to consider the implementation of TLS for secure data transport.

Rony discussed the implementation of a secure encryption infrastructure using Java's factory classes, emphasizing the importance of using long-term support versions of Java for security updates. He demonstrated how to set up system properties in Java to provide the certificate file's location to the Java program, and how to use SSL/TLS in a secure manner. Rony also explained the use of Java utility classes to wrap up streams into readers and writers, and to buffer data for exchange between sockets. He concluded by encouraging further study of Java socket programming and the available documentation, and reminded participants to submit their small examples via email.