Struts Modernisation & Migration
Your Struts applications still power core operations. We'll help you modernise them safely.
Why Struts Applications Are Still Running Your Business
Apache Struts applications remain in production because they work. Built during the framework's dominance of enterprise Java, they power core business logic, internal platforms, customer portals, and transaction processing systems that organisations depend on daily. Many have been running reliably for fifteen years or more.
But the landscape has changed. Struts 1 reached end-of-life years ago. Early Struts 2 versions carry well-documented security vulnerabilities that have been exploited in high-profile breaches. The framework's architecture patterns feel dated compared to modern Java development, making changes slow and risky. Integration with contemporary systems requires workarounds that accumulate technical debt.
The applications still function, but the risk profile has shifted. Maintaining the status quo becomes more expensive and more dangerous each year. The question is how to modernise without disrupting the operations these systems support.
Common Struts Risks
Struts applications that have served reliably for years now carry risks that compound over time and become increasingly difficult to manage.
Legacy MVC Structure Limiting Change
Struts' action-based MVC pattern couples presentation, business logic, and data access in ways that make changes difficult. Modifying one area often requires changes across multiple layers, increasing risk and slowing delivery.
Security Vulnerabilities and Patch Concerns
Struts has a documented history of critical vulnerabilities, including remote code execution flaws. Struts 1 receives no patches. Even supported Struts 2 versions require careful attention to stay secure. Security teams flag these applications as high-risk.
Tightly Coupled Monolith Architecture
Most Struts applications evolved as monoliths with intertwined components. This makes scaling difficult, testing complex, and deployment risky. A change in one module can break seemingly unrelated functionality elsewhere.
Fragile Deployment Pipelines
Build and deployment processes often rely on legacy tooling, manual steps, and tribal knowledge. Releases are stressful events rather than routine operations. Recovery from failed deployments can take hours or days.
Shrinking Pool of Expertise
Few Java developers want to work with Struts today. Those who can are expensive and hard to find. When key team members leave, replacing their knowledge becomes a serious challenge.
Integration Difficulty
Connecting Struts applications to modern APIs, cloud services, and contemporary frontends requires significant workarounds. Each integration adds complexity and creates additional maintenance burden.
Migration Is Not Just Framework Replacement
The temptation to swap Struts for Spring Boot and consider the job done misunderstands what modernisation requires. Simply changing frameworks without addressing underlying architecture issues produces a modern-looking application with the same problems.
Why Full Rewrites Often Fail
- Business logic accumulated over years is more complex than specifications capture
- Edge cases and implicit requirements only surface when the new system goes live
- Parallel development creates confusion about which system is authoritative
- Timelines extend as discovered requirements accumulate
- User resistance grows as familiar interfaces change all at once
Effective modernisation addresses architecture, security, maintainability, and delivery practices together. It proceeds incrementally, validating each change before moving forward, and keeps the business running throughout.
Staged Migration Paths
There's no single correct approach to Struts modernisation. The right path depends on your application's architecture, your team's capabilities, and your business constraints. We help you choose and execute the appropriate strategy.
Stabilise the Existing Platform
Sometimes the priority is reducing immediate risk without major architectural changes. We address security vulnerabilities, improve test coverage, modernise build pipelines, and document the system—creating a stable foundation for future migration.
Isolate Domains and Services
We identify bounded contexts within the monolith and introduce clear boundaries between them. This reduces coupling, makes the codebase more testable, and prepares specific domains for independent migration.
Introduce API Layers
Modern REST APIs are created around existing Struts functionality. This enables integration with contemporary systems, mobile applications, and frontend frameworks without modifying the core application immediately.
Struts to Spring Boot Migration
Actions, forms, and services are migrated incrementally to Spring Boot equivalents. The strangler fig pattern allows old and new code to coexist, with traffic gradually shifting to modernised components.
Monolith to Modular Architecture
For larger applications, we decompose the monolith into independently deployable modules or services. This improves scalability, enables team autonomy, and reduces deployment risk.
Incremental UI Modernisation
Legacy JSP interfaces can be progressively replaced with modern frontend frameworks. API layers enable React, Angular, or Vue frontends to consume existing backend functionality during transition.
Our Approach
We follow a structured process that prioritises understanding the existing system before proposing changes, and validates every modification against real production behaviour.
Architecture Mapping and Dependency Analysis
We analyse your Struts application comprehensively: actions, forms, configuration files, service layers, data access patterns, and external integrations. We identify component boundaries, coupling points, and dependencies that will affect migration sequencing.
Behaviour Validation Using Real System Outputs
Before changing anything, we capture how the system actually behaves. We record request/response patterns, business calculations, state transitions, and integration touchpoints. This creates a validation baseline that ensures modernised components produce identical results.
Phased Migration Plan
We develop a migration roadmap that sequences work based on risk, business value, and technical dependencies. Each phase delivers working functionality and reduces overall system risk. Clear milestones and decision points allow course correction as needed.
Parallel Verification to Protect Business Continuity
Critical components run alongside their Struts predecessors during transition. We compare outputs continuously to verify correctness. Cutover happens only when we're confident the modernised component matches or exceeds the original's reliability. Your operations continue without interruption.
Benefits of Modernisation
Improved Security Posture
Modern frameworks receive regular security updates. Known vulnerabilities are addressed. Security teams can sign off on the application. Compliance requirements are met without exceptions or compensating controls.
Faster Development Cycles
Modern Java architecture, better tooling, and reduced coupling accelerate delivery. Features that took weeks in Struts can be built in days. Deployments become routine rather than stressful events.
Easier Integration
Connect to REST APIs, cloud services, message queues, and modern databases using native patterns. Authentication, authorisation, and data handling work as contemporary systems expect.
Maintainable Java Architecture
Clean, well-structured code following current Spring Boot conventions. Comprehensive test coverage. Documentation that reflects actual system behaviour. Code that any competent Java developer can understand and extend.
Easier Hiring and Onboarding
Spring Boot skills are widely available. Developers want to work with modern frameworks. New team members contribute quickly without learning legacy patterns. Knowledge concentration risk decreases.
Reduced Operational Risk
Modern deployment pipelines, containerisation, and observability tools improve reliability. Issues are detected and resolved faster. Recovery from problems takes minutes rather than hours.
What You Receive from an Engagement
Every engagement produces concrete, documented outputs that provide value regardless of next steps. You're not dependent on us to act on the findings.
Written Assessment
A comprehensive analysis of your Struts application: architecture, dependencies, security concerns, and modernisation options. Written in plain language for both technical and business stakeholders.
Architecture Diagram
Visual representation of current system structure: components, boundaries, data flows, and integration points. Annotated with risk areas and modernisation opportunities.
Migration Roadmap
A phased plan with clear milestones, effort estimates, and decision points. Includes recommended sequencing, risk mitigation strategies, and resource requirements.
Proof-of-Concept Options
Recommendations for initial pilots that demonstrate feasibility and build confidence. Typically focused on representative components that validate the chosen migration approach.
Common Questions About Struts Modernisation
Is Spring Boot the only migration target?
Spring Boot is the most common target for Struts migration because it's the natural evolution for enterprise Java applications. However, we also support migrations to other frameworks like Quarkus or Micronaut where they better fit your requirements. The right choice depends on your team's skills and strategic direction.
How long does Struts modernisation typically take?
Timelines depend on application size and complexity. Assessment typically takes 2-4 weeks. Full migration of medium-sized applications spans 6-12 months, delivered in phases that each provide working functionality. Large enterprise systems may take longer but deliver value incrementally throughout.
Can we address security concerns before full migration?
Yes. Security stabilisation is often the first phase of engagement. We can address known vulnerabilities, improve monitoring, and reduce attack surface while planning longer-term modernisation. This buys time for a considered migration approach.
What happens to our existing database and integrations?
Database schemas typically remain unchanged during initial migration phases. We modernise data access patterns without restructuring your data. Existing integrations are preserved or improved with modern API patterns. Nothing breaks during transition.
Do we need to stop development during migration?
No. We design migration approaches that allow continued development on both legacy and modernised components. Critical bug fixes and necessary features can proceed. The strangler fig pattern specifically enables parallel work on old and new systems.
Request an Initial Assessment
Tell us about your Struts application and we'll provide a written assessment of your modernisation options. No call required to start—just send us the details and we'll respond with initial findings and recommendations.
No obligation. No sales pitch. A practical written analysis you can use regardless of next steps.