Technology

Legacy Java Application Support

Java 8 → 17/21 upgrades, Spring Boot migration, EJB modernisation, Oracle JDK licensing resolution, application server decommissioning, and ongoing support.

We take over legacy Java codebases. Australian owned and operated.

Book a 20-min scoping call Emergency Java Fix
  • AU-built Australian owned and operated
  • Java 8 → 17/21 Upgrades Stack we work with daily
  • Spring Boot & EJB Migration New builds + modernisation
  • Fixed Price scopes, no surprises
Legacy Java

Your Java application still works, but the technology around it has moved on

Legacy Java is everywhere. Enterprise applications built on Java 6, 7, or 8 running business-critical processes for years, sometimes decades. They work. They are reliable. But the JDK is end-of-life, the framework is outdated, the application server costs a fortune in licensing, and nobody wants to touch the code.

The most common scenario: a Java application that the business depends on, built by a team that no longer exists. The original architect left. The consulting company that built it is gone. The code is undocumented. But it runs payroll, processes orders, or manages inventory. It cannot just be switched off.

We take over legacy Java codebases. Audit the application, upgrade the JDK, modernise the framework (Spring Boot 3), decommission expensive application servers, and provide ongoing support. No judgement about the code. We just make it maintainable.

Legacy Java application modernisation with JDK upgrade and Spring Boot migration
How it runs

A legacy Java support & upgrade project, end to end

Three stages. No surprises. Your live system stays untouched until cutover — delivered personally by the founder.

  1. Week 0

    Java Audit

    15-minute scoping call. We map your current JDK and framework versions, app-server, Maven / Gradle build and licensing posture, and the upgrade or support path. Fixed-price quote inside 48 hours.

  2. Weeks 1–N

    Build / Upgrade & Parallel-Run

    Work performed in a staging environment first. Parallel-run against your live application for safe iteration. Every JDK, Spring and dependency change tested before production.

  3. Cutover

    Go-Live & Handover

    Production cutover on a planned window. Team training, monitoring active, 30 days post-launch support. Documentation and source code handed over in full.

Founder profile

Kasun Wijayamanna

Founder · Perth, WA · Started HELLO PEOPLE in 2008

18+ Years running HELLO PEOPLE

Founded in 2008. Two decades of technology-driven business transformation across Australia.

100+ Projects delivered

Startups to government agencies across mining, healthcare, legal, education and more.

HDR Researcher · Curtin University

Postgraduate research in Artificial Intelligence and Retrieval-Augmented Generation (RAG).

MBA Oil & Gas

Deep technical expertise combined with strong business and financial acumen.

Perth Based in WA

Serving businesses across Western Australia and nationally.

AU+TH International experience

Professional background in Bangkok, Thailand before migrating to Perth.

PHF Paul Harris Fellow · Rotary

Former President of Rotary Club of Booragoon. Over a decade of community service.

Read the full bio — research, career, community involvement and how HELLO PEOPLE runs projects.

See full founder page
What We Do

Legacy Java support services: by type

JDK upgrades, Spring migration, security patching, ongoing support, and application server decommissioning.

Java Version Upgrades (8 → 17/21)

Java 8 was released in 2014 and is still the most widely deployed Java version. Oracle changed the licensing model: post-2019 Java 8 updates from Oracle require a commercial licence. Many businesses are stuck on the last free Java 8 update or have unknowingly lapsed their licence.

Java 17 (LTS, released 2021) and Java 21 (LTS, released 2023) are the current long-term support versions. The upgrade path involves handling removed APIs (Nashorn JavaScript engine, Java EE modules), updating dependencies, and resolving breaking changes in newer JDKs.

Spring Framework & Spring Boot Migration

Spring Framework 4.x and 5.x to Spring Framework 6 / Spring Boot 3. The big jump: Spring 6 / Spring Boot 3 requires Java 17+ and Jakarta EE (javax → jakarta namespace change). This namespace migration affects every import statement using javax.servlet, javax.persistence, javax.validation.

Spring MVC → Spring Boot migration for applications that never adopted Boot. Older Spring applications using XML configuration migrated to Java configuration and annotations. Spring Security configuration updates (the security configuration DSL has changed significantly).

Security Patching & Vulnerability Fixes

Java applications with security vulnerabilities. Log4j (CVE-2021-44228) was the headline, but there are many more: outdated libraries in the classpath, insecure deserialization, XML entity injection, and JDBC injection.

We run dependency analysis (OWASP Dependency-Check, Snyk), review authentication and authorisation logic, check for common Java vulnerabilities, and fix everything. Maven/Gradle dependencies updated to patched versions.

Ongoing Java Application Support

Monthly support plans for legacy Java applications. Bug fixes, security monitoring, dependency management, performance investigations, and small feature requests. A developer who knows your codebase.

Many legacy Java applications run critical business processes but nobody in the organisation understands the code. The original developer left years ago. The application works, but nobody dares touch it.

Application Server Modernisation

Legacy Java applications running on WebSphere, WebLogic, JBoss/WildFly, or GlassFish. These heavyweight application servers are expensive (licensing), complex (configuration), and increasingly unnecessary.

Modern Java applications run on embedded servers: Spring Boot with embedded Tomcat, Jetty, or Undertow. The application is a single JAR file that starts with `java -jar`. No application server installation, no EAR/WAR deployment, no JNDI configuration.

Java version upgrade from Java 8 to Java 17/21 LTS with dependency resolution
Spring Framework migration from 4.x/5.x to Spring Boot 3 with Jakarta EE namespace changes
Java security patching with OWASP dependency check and Log4j vulnerability remediation
Ongoing legacy Java application support with documentation, CI/CD, and maintenance
Java application server migration from WebSphere/WebLogic to Spring Boot with embedded Tomcat
Capabilities catalogue

Legacy Java support & upgrade services we deliver

Every capability below has been delivered for a real Australian business — from a single Java 8 to Java 21 JDK upgrade to a full Struts / WebSphere rebuild on Spring Boot 3 with zero-downtime cutover. If your scenario is not listed, ask — we build bespoke.

Java 8/11 → Java 21 upgrade

  • Java 6 / 7 → Java 21 LTS multi-step incremental upgrade
  • Java 8 → Java 17 / 21 with removed-API remediation
  • Java 11 → Java 21 LTS upgrade with virtual-thread adoption
  • Oracle JDK → Eclipse Temurin / Amazon Corretto / Azul Zulu migration
  • Nashorn JavaScript engine removal and replacement
  • Removed Java EE modules (CORBA, JAXB, JAX-WS) re-bundling
  • JPMS modularisation evaluation for large monoliths
  • Ant → Maven / Gradle build-system modernisation

Spring Framework → Spring Boot 3 upgrade

  • Spring Framework 3 / 4 / 5 → Spring Framework 6 upgrade
  • Spring Boot 1.x / 2.x → Spring Boot 3 with autoconfig refresh
  • javax.* → jakarta.* namespace migration (OpenRewrite automated)
  • Spring Security 5 → Spring Security 6 DSL rewrite
  • XML-based Spring config → annotation / Java config rebuild
  • Spring MVC → Spring WebFlux evaluation and migration
  • Spring Data JPA / Hibernate 5 → Hibernate 6 upgrade
  • WAR-on-app-server → executable Spring Boot fat JAR conversion

Struts / Java EE → modern Java migration

  • Apache Struts 1 / 2 → Spring Boot + Thymeleaf / React rewrite
  • JSF / PrimeFaces → Spring Boot + REST + SPA modernisation
  • EJB 2.x / 3.x → Spring Service + Spring Data JPA replacement
  • WebSphere / WebLogic / JBoss → embedded Tomcat / Jetty cutover
  • JNDI / JMS proprietary bindings → Spring abstraction migration
  • JSP / Servlet legacy UI → Thymeleaf or headless API + SPA
  • CORBA / RMI → REST / gRPC modernisation
  • Legacy Hibernate 3 / 4 → Hibernate 6 with Jakarta Persistence

Long-term Java support

  • Monthly retainer covering security patches and dependency updates
  • On-call emergency Java / JVM / app-server incident response
  • Quarterly Java + framework version compatibility audit
  • Proactive APM (New Relic / Datadog / Dynatrace) monitoring
  • Code-takeover after previous developer / team exit
  • Jenkins / GitHub Actions / GitLab CI setup as part of onboarding
  • SLA-backed turnaround for bug fixes and small feature requests
  • Roadmap planning for next Java LTS upgrade window

Security patching & dependency audit

  • Log4Shell (CVE-2021-44228) and Spring4Shell remediation
  • OWASP Dependency-Check / Snyk / Dependabot CVE remediation
  • Insecure deserialisation (Jackson, XStream) hardening
  • XML external entity (XXE) and SQL injection remediation
  • Spring Security configuration audit and MFA rollout
  • TLS / cipher-suite hardening on Tomcat, Jetty and app servers
  • JKS / keystore rotation and secret-management adoption
  • Penetration test remediation and OWASP ASVS gap-fix programme

Performance & JVM tuning

  • G1 / ZGC / Shenandoah garbage collector selection and tuning
  • Heap-dump analysis and memory-leak remediation
  • Thread-dump analysis for contention and deadlock investigation
  • Virtual threads (Java 21) adoption for I/O-bound services
  • JIT warm-up and tiered-compilation tuning for low-latency APIs
  • Hibernate / JPA N+1 query elimination and second-level cache
  • JDBC connection-pool tuning (HikariCP) and query optimisation
  • GraalVM native-image evaluation for fast-start microservices
Legacy database migration project
Case Study

Legacy database migration that preserved 15 years of data

We migrated a sporting club from Microsoft Access to a modern web platform. Fifteen years of member data, registrations and competition records. Safely moved and now cloud-accessible.

Read the full case study
15 yrs Data preserved
100% Cloud accessible
50% Less admin time
Why Modernise

Why upgrading your Java application matters

Oracle Java licensing comparison with free JDK distributions like Temurin and Corretto

Stop paying Oracle Java licensing, or sort it out properly

Oracle changed Java licensing in January 2023. The "Oracle Java SE Universal Subscription" is now priced per-employee (not per-installation). For a 100-person company, that is roughly US$15 per employee per month, US$18,000/year for Java.

Most businesses do not need Oracle JDK. Eclipse Temurin, Amazon Corretto, and Azul Zulu are free, open-source JDK distributions with long-term support. Same Java, no licence fees.

If your organisation is running Oracle JDK without a current subscription, you may be out of compliance. We help sort this out: migrate to a free JDK distribution, ensure your Java version is supported, and remove the licensing risk.

Java performance improvements with ZGC, virtual threads, and GraalVM native compilation

Modern Java is significantly faster

Java 17 and 21 include years of garbage collection improvements, JIT compiler optimisations, and language features that enable better code. ZGC and Shenandoah garbage collectors virtually eliminate GC pauses. Virtual threads (Java 21) dramatically improve throughput for I/O-bound applications.

Spring Boot 3 with GraalVM native image compilation produces executables that start in milliseconds instead of seconds. For microservices and containerised deployments, this is transformative.

Startup time, memory usage, and throughput all improve significantly on modern Java. For applications running on cloud infrastructure, this directly translates to lower compute costs.

Modern Java developer experience with Java 21 features and Spring Boot 3

Modern Java attracts better developers

Nobody wants to work on a Java 6 application with EJB 2.x, JSP views, and an Ant build. Candidates ask about the tech stack. "Java 8 with Spring MVC on WebSphere" signals technical debt and slow-moving management.

"Java 21, Spring Boot 3, Docker, Kubernetes" tells developers the team is competent, the codebase is modern, and the work will be interesting. Hiring is dramatically easier.

Existing team members benefit too. Modern Java (records, sealed classes, pattern matching, text blocks) is a significantly better language. Modern Spring Boot is a pleasure to work with compared to legacy Spring XML configuration.

Java cloud deployment with Docker containers, Kubernetes, and CI/CD pipelines

Modern Java deploys to cloud natively

Legacy Java applications running on heavyweight application servers are difficult to containerise. Modern Spring Boot applications produce a single JAR or Docker image that deploys to any cloud platform.

Kubernetes, Azure App Service, AWS ECS, Google Cloud Run. All designed for containerised applications. Modern Java fits this model naturally. Legacy Java on WebSphere or WebLogic does not.

CI/CD pipelines for modern Java are straightforward. Maven or Gradle build, Docker image, push to registry, deploy. No more complex EAR deployments to application servers.

Support Services

Legacy Java support and maintenance

Emergency fixes, security audits, code takeovers, and monthly support plans.

Emergency Java Fixes

Production down? Critical bug? Security vulnerability like Log4Shell? We respond to Java application emergencies quickly.

Security Audit

OWASP Dependency-Check, code review, authentication/authorisation analysis, and Java vulnerability assessment.

Dependency Management

Maven/Gradle dependencies audited, updated, and untangled. Abandoned libraries replaced with maintained alternatives.

Code Takeover

Original Java developer gone? We audit the codebase, document the architecture, set up CI/CD, and resume development.

Performance Profiling

JVM tuning, garbage collection analysis, thread dump analysis, memory leak detection, and database query optimisation.

Monthly Support Plans

Retainer-based support. Bug fixes, security patches, dependency updates, monitoring, and feature development.

Common Scenarios

Legacy Java situations we handle

If one of these sounds familiar, talk to us.

01

Java 8 → Java 17/21

The most common upgrade. Java 8 to current LTS. Resolve removed APIs, update dependencies, sort out JDK licensing.

02

Spring MVC → Spring Boot

Legacy Spring application modernised to Spring Boot. XML config → annotations. WAR → executable JAR. Embedded server replaces app server.

03

javax → jakarta Migration

Java EE namespace change. Every javax.servlet, javax.persistence, and javax.validation import updated for Spring Boot 3 / Jakarta EE.

04

WebSphere/WebLogic → Spring Boot

Expensive application server replaced with Spring Boot embedded Tomcat. Lower costs, simpler deployment, cloud-ready.

05

Developer Left

Java developer or team moved on. Nobody understands the legacy code. Need someone to take over and maintain it.

06

Oracle JDK Licensing Issue

Oracle Java licence compliance concern. Migration to free JDK distribution (Temurin, Corretto) to eliminate licensing fees and risk.

How It Works

Legacy Java modernisation: step by step

Assess, build, upgrade, test, deploy. Everything in staging before production.

1. Application Assessment

Review the codebase, build system (Maven/Gradle/Ant), Java version, application server, Spring version, and all dependencies. Identify EOL components, security vulnerabilities, and upgrade blockers. You get a detailed report.

2. Build & CI/CD Setup

Build system modernised if needed (Ant → Maven/Gradle). CI/CD pipeline configured. Staging environment set up matching production. Tests run as baseline.

3. JDK & Framework Upgrade

JDK upgraded to target version. Spring, Hibernate, and other frameworks upgraded. Jakarta namespace migration. Removed APIs replaced. All compile errors resolved.

4. Dependency Updates

Maven/Gradle dependencies updated to current versions. Abandoned libraries replaced. Security vulnerabilities in the dependency tree resolved.

5. Testing & Deployment

Full test suite run. Manual testing of critical workflows. Performance benchmarked. Deployed to staging, validated, then deployed to production with rollback plan.

6. Post-Upgrade Monitoring

Application monitored for 4 weeks post-upgrade. JVM metrics, error tracking, and performance comparison. Issues caught and resolved promptly.

Technical Context

Technologies involved in Java modernisation

JDK, frameworks, databases, build tools, and cloud platforms.

Java Development

Our main Java page covering new Java projects, Spring Boot development, and enterprise applications.

Spring Boot

The modern Java application framework. Most Java modernisations target Spring Boot as the platform.

Oracle / PostgreSQL

The database behind many legacy Java applications. Oracle to PostgreSQL migration is common alongside Java upgrades.

Docker & Kubernetes

Containerised deployment for modernised Java applications. Replaces heavyweight application servers.

AWS / Azure

Cloud deployment for Java applications. ECS, EKS, Azure App Service, and managed Kubernetes.

Maven / Gradle

Java build tools. Dependency management, build automation, and CI/CD integration.

Our Java 8 application on WebSphere was costing us $40,000/year in licensing. HELLO PEOPLE migrated it to Java 21 + Spring Boot 3 + Docker in twelve weeks. Runs on AWS now at a fraction of the cost. WebSphere is gone and nobody misses it.

IT Director Logistics company, Melbourne
FAQs

Common questions about legacy Java support

Is Java 8 still supported?

Oracle Java 8 public updates ended January 2019 for commercial use. Extended support requires an Oracle Java SE Subscription. Free alternatives: Eclipse Temurin, Amazon Corretto, and Azul Zulu all provide Java 8 builds with security patches. But upgrading to Java 17 or 21 is the better long-term path.

How much does a legacy Java upgrade cost?

We audit the existing application and provide a fixed-price quote. Java version upgrade only (8 → 17/21) sits at the lower end of project size. Spring Framework migration (Spring MVC → Spring Boot 3) is larger. Full modernisation (Java 8 + EJB + WebSphere → Java 21 + Spring Boot 3 + Docker) runs higher.

How long does the upgrade take?

Java version jump only: 2-4 weeks. Spring migration: 4-10 weeks. Full modernisation: 8-20+ weeks. The main variables are application size, framework complexity, and the number of proprietary app server dependencies.

What about the javax → jakarta namespace change?

Spring Boot 3 / Spring Framework 6 require Jakarta EE (jakarta.* packages instead of javax.*). This affects every import statement using javax.servlet, javax.persistence, javax.validation, etc. Tools like OpenRewrite automate most of the change, but testing is still needed.

Can we migrate from Oracle JDK to a free alternative?

Yes. Eclipse Temurin, Amazon Corretto, and Azul Zulu are drop-in replacements for Oracle JDK. Same Java, same APIs, fully compatible. We swap the JDK, test the application, and verify everything works. Usually takes 1-2 days plus testing.

What about our EJB components?

EJB (Enterprise JavaBeans) is effectively dead in modern Java development. We migrate EJB components to Spring equivalents: Session Beans → Spring Services, Entity Beans → JPA/Spring Data, Message-Driven Beans → Spring JMS or Spring AMQP.

Can you take over our Java application from the original developer?

Yes. Legacy Java codebase takeover is a core service. We need repository access and server/deployment access. We audit the code, document the architecture, set up CI/CD, and handle ongoing maintenance.

Should we upgrade or rebuild from scratch?

Depends on the codebase quality and business requirements. If the architecture is sound and the application does what the business needs, upgrading is usually cheaper and faster. If the architecture is fundamentally broken or the business needs have changed significantly, a rebuild may be the better investment. We assess and advise honestly.

Tell Us About Your Java Application

Java version, framework, application server, and what you need done. We will audit and come back with a plan.

Prefer a quick chat? Call 0425 531 127. We answer the phone in Perth.