From Legacy to Modern: Streamlining Java and AS/400 Integration with JT400

          What if you could bridge the gap between old and new? 
       The answer is JT400—your bridge to a modernized IBM iSeries.

Introduction

The IBM iSeries (formerly known as AS/400) is a robust platform recognized for its reliability and scalability in enterprise environments. While it traditionally relies on RPG and COBOL programming, integrating modern technologies like Java has opened new possibilities for developers. This blog explores the benefits, approaches, and key integration features using JT400.

What is JT400?

JT400, also known as the IBM Toolbox for Java, is a collection of Java classes that enables developers to access and manipulate data on iSeries systems. It serves as a bridge between Java applications and IBMi resources, such as databases, programs, and data queues.

Key Features of JT400 

• Seamless Integration: Smoothly integrates Java applications with IBMi systems.
• Platform Independence: Ensures compatibility across different platforms.
• Simplified Development: Provides a set of Java classes for simplified development.
• Enhanced Security: Incorporates security measures for secure communication.
• Performance Optimization: Optimizes performance for efficient operations.

How to Use JT400 with Java

We need to include the JT400.jar file in the project’s classpath. 

Prerequisites:

• OS/400 V5R3 or later
• JT400 Library
• JDK

Now depending on if you are using Maven, Gradle or a normal Java program, there are three ways to include JT400 dependency.

• In Gradle project (add implementation in dependencies. gradle)

• In the Maven project (add dependency in pom.xml)

• In a normal Java project: Add the JAR file to the project’s classpath.

Establishing a Connection to IBMi

With the provided Java code, a connection can be established to IBMi (AS/400) systems

In this code, a connection is established to an IBMi system, a success check is performed, and then the connection is disconnected from the system.

Note: Error handling is included to deal with potential exceptions during the connection process.

Perform Database Operations using JDBC

The provided Java code demonstrates how to perform database operations on an IBMi (AS/400) system using JDBC.

In summary, this code connects to an IBMi system, executes a SELECT query on a specified table, processes and prints the results, and then closes the resources. Error handling is included to handle potential exceptions during the database operation.

Calling RPG Programs from Java using PCML

PCML (Program Call Markup Language) files facilitate the calling of RPG programs from Java. Ensure that PCML definitions match         RPG    program parameters.

Example PCML File

Java Code for Program Invocation

Note: Ensure precise matching between PCML definitions and RPG program parameters to avoid errors during program calls.

Calling AS400 Commands from Java

Calling AS400 commands from Java involves using the JT400 library, which provides a convenient way to interact with IBM iSeries systems.

The following code snippet demonstrates how to call AS400 commands from Java using JT400:

Deployment of Java on IBMi

1. Deploy Java JAR on the FTP server of IBMi
2. Submit a job to run Java using the following command:

Benefits of Java and IBMi Integration

1. Enhanced Data Accessibility: Access and manipulate data on iSeries systems seamlessly.
2. Cross-platform Compatibility: Ensure compatibility across different platforms.
3. Web and Mobile Development: Facilitate modern web and mobile development.
4. Streamlined Business Processes: Efficiently integrate and streamline business operations.
5. Extensive Libraries and Frameworks: Leverage the rich ecosystem of Java libraries and frameworks.
6. Modern and Robust Language: Utilize Java’s modern language features and robustness.
7. Enterprise Support: Benefit from Java’s widespread enterprise support.

Integration Approaches

1. JDBC (Java Database Connectivity): Connect to databases on iSeries systems.
2. Web Services: Use web services for communication.
3. IBM Toolbox for Java: Employ JT400 as a bridge for various operations.

Conclusion

Integrating Java with IBMi using JT400 provides a powerful solution for accessing and manipulating data on iSeries systems. No matter what the integration process is, JT400 simplifies it, making it seamless, secure, and efficient, regardless of whether it is using JDBC to operate on databases or PCML to call RPG programs. Enhanced data accessibility, cross-platform compatibility, and streamlined business processes demonstrate the importance of such integration in modern enterprise computing.