How to Migrate Java Applications to AWS Cloud

TL;DR:

• Set clear goals, budget, and train your team before migrating.
• Use AWS tools like EC2, Beanstalk, RDS, Lambda, and CloudWatch.
• Follow a step-by-step migration process from assessment to deployment.
• Understand AWS migration strategies like Rehost, Replatform, Refactor.
• Tackle challenges like downtime, security, and compatibility.
• CrossAsyst offers expert support for smooth Java-to-AWS migration.

The global application server market size was valued at USD 25.64 billion in 2024 and is anticipated to grow at a CAGR of 14.2% from 2025 to 2030. The increasing reliance on web-based applications for business operations and customer engagement is a primary growth driver in the application server market. 

As businesses undergo significant digital transformation to stay competitive, they need robust platforms that can efficiently host, manage, and scale dynamic web applications. Migrating Java applications to AWS Cloud offers a powerful solution to meet these needs.

According to MarketsandMarkets, cloud-native transformation is a top priority for enterprises, with Java applications being among the most migrated workloads due to their legacy complexity and business-critical nature. AWS offers flexible paths for modernizing or rehosting Java systems depending on your goals.

This blog will guide you through migrating Java applications to AWS Cloud in a structured and seamless manner. 

Planning and Prerequisites for Java App Migration to AWS Cloud

Before migrating your Java applications to AWS Cloud, careful planning and preparation are essential to ensure a smooth transition. By setting clear objectives and organizing resources up front, you can minimize potential disruptions and optimize the migration process. Here are the key areas to address:

1. Define Clear Objectives

Clearly define your migration goals. Whether it’s improving scalability, enhancing security, or reducing operational costs, knowing what you want to achieve will help you make informed decisions throughout the process.

• Set measurable KPIs like response times, infrastructure savings, or deployment frequency.

2. Review Security and Compliance Needs

Security is a top priority when migrating to the cloud. Make sure that your applications meet the necessary security standards and compliance regulations (e.g., GDPR, HIPAA).

• Use AWS security services like:
  • AWS Identity and Access Management (IAM)
  • AWS Key Management Service (KMS)
  • AWS Shield for DDoS protection
    
• Run a pre-migration compliance checklist to identify gaps.

3. Conduct Preliminary Environment Checks

Evaluate your current Java application’s architecture, dependencies, and performance metrics. Identify compatibility issues or resource bottlenecks early to streamline migration.

• Use AWS Application Discovery Service or Migration Evaluator to assess server health and resource mapping.
• Document configurations and validate network dependencies.

4. Team Training and Resource Allocation

Ensure that your team is well-equipped to handle the migration and manage the cloud environment afterward.

• Assign clear roles for application owners, cloud engineers, and DevOps leads.
• Utilize AWS Training and Certification resources.

5. Plan Budget & Timeline

Define a clear budget considering AWS service costs, labor, and potential downtime expenses. Establish a phased timeline to prioritize critical workloads and minimize disruptions. Use AWS pricing calculators to estimate cloud expenditure and align migration milestones with business objectives. Regularly review progress to stay on track and optimize resource allocation.

By completing these planning steps and prerequisites, you’ll ensure a successful Java application migration to AWS Cloud. This positions your business to fully leverage the cloud’s scalability, flexibility, and cost-efficiency.

Pro Tip:
Run a Cloud Readiness Assessment with AWS Migration Evaluator to uncover cost-saving opportunities and identify migration risks before you start.

Also Read: All You Need to Know About EKS (AWS Elastic Kubernetes Service)

Key AWS Tools and Services for Java Applications

AWS provides a robust suite of tools and services that are well-suited for migrating, deploying, and managing Java applications in the cloud. These services offer scalability, security, and efficiency, helping businesses optimize their Java workloads. Here are five key AWS tools and services you can leverage for your Java applications:

1. Amazon EC2 (Elastic Compute Cloud)

Amazon EC2 provides resizable compute capacity in the cloud, offering flexibility to choose virtual machines tailored to your Java applications’ needs.

• Use case: Ideal for lift-and-shift migrations or apps that require OS-level control.
• Benefits:
  • Auto-scaling and load balancing
  • Support for custom environments and legacy JDK versions
  • Integration with ELB and Amazon CloudWatch

Learn more: Amazon EC2

2. AWS Elastic Beanstalk

AWS Elastic Beanstalk simplifies the deployment and management of Java applications by automating infrastructure provisioning, scaling, and monitoring.

• Use case: Great for teams using frameworks like Spring Boot or Java EE who want to avoid infrastructure setup.
• Benefits:
  • Auto-scaling and environment health checks
  • Easy integration with RDS and S3
  • Supports Git-based deployment

Learn more: Elastic Beanstalk

3. Amazon RDS (Relational Database Service)

Amazon RDS offers a fully managed database solution for Java applications using MySQL, PostgreSQL, or Oracle.

• Use case: Replace on-prem databases during migration with minimal code changes.
• Benefits:
  • Automated backups, patches, and scaling
  • Multi-AZ availability and read replicas
  • Built-in monitoring

Learn more: Amazon RDS

4. AWS Lambda

AWS Lambda enables serverless execution of Java applications, ideal for microservices or event-driven use cases.

• Use case: Refactored Java apps with specific functions (e.g., file processing or scheduled jobs).
• Benefits:
  • No server management
  • Event-driven invocation
  • Integrates with S3, DynamoDB, API Gateway

Learn more: AWS Lambda

5. Amazon CloudWatch

Amazon CloudWatch provides real-time monitoring of applications running on AWS.

Detect and resolve anomalies quicklydeploy, and scale your Java applications in the cloud, taking full advantage of the cloud’s flexibility, reliability, and cost efficiency.

• Use case: Monitor JVM metrics, error logs, or API performance.
• Benefits:
  • Custom alarms and dashboards
  • Log analytics and cost optimization insights

Learn more: Amazon CloudWatch

Pro Tip:
Use AWS Well-Architected Tool during your Java application migration to assess whether your architecture follows AWS best practices for cost, reliability, and performance.

Also Read: A Guide to Deploying DeepSeek R1 on AWS Bedrock

Steps for Java Applications Migration to AWS Cloud

Migrating your Java applications to AWS Cloud involves several well-defined steps to ensure a smooth and efficient transition. Each step requires careful planning and execution to minimize downtime, ensure data integrity, and optimize performance. Below are the key steps to follow when migrating your Java applications to AWS:

Step1: Assess Your Current Application

Start by evaluating the full scope of your application ecosystem:

• Use AWS Migration Hub or AWS Application Discovery Service to get visibility into your workloads.
• Review the application architecture: monolith or microservices.
• Audit your codebase, libraries, runtime dependencies, and APIs.
• Identify integration points like on-prem systems, third-party APIs, and databases.
• Flag legacy elements that need upgrades or replacements (e.g., older JDKs).

Step 2: Choose the Right AWS Services

AWS offers a wide array of services that can be tailored to your specific Java application needs. It’s crucial to select the right set of services for compute, storage, databases, networking, and security. Common AWS services used in Java application migration include:

• Amazon EC2 for compute resources
• Amazon RDS or Amazon Aurora for managed database solutions
• AWS Elastic Load Balancing for traffic distribution
• AWS Elastic Beanstalk for easy application deployment and management. 

Your chosen services should align with your migration strategy and meet your application’s performance, scalability, and security requirements.

Step 3: Prepare the Application for the Cloud

Before migrating, you need to prepare your Java application for the cloud environment. This step includes:

• Code Optimization: Ensure that your code is optimized for cloud environments. For example, you may need to update your application to use cloud-native features like managed databases or storage.
• Database Migration: If your Java application relies on a database, you will need to plan for data migration. You can use AWS Database Migration Service (DMS) to migrate your data with minimal downtime.
• Dependency Management: Address any dependencies that your application relies on, including third-party libraries, middleware, and services.

Step 4: Test the Migration in a Staging Environment

Create a mirror of your production environment in AWS to:

• Validate CI/CD pipelines with tools like AWS CodePipeline or Jenkins.
• Test database connections, API calls, file I/O, and user sessions.
• Simulate peak loads using tools like Apache JMeter or Gatling.
• Identify bottlenecks in performance, scaling, or network latency.

Step 5: Migrate the Application

With your staging environment tested and validated, you can proceed with the actual migration. You can choose any migration strategy that is suitable for you. Here are the 7Rs of AWS migration:

• Retain: This strategy involves keeping your applications running as they are on-premises, with the intention of revisiting the migration at a later stage. This is ideal for applications that may not be ready for the cloud yet.
  
• Retire: If there are applications that are no longer necessary or have become obsolete, you can decommission them during the migration process. This can help reduce costs and complexity in your cloud environment.
  
• Repurchase: In some cases, it might be more efficient to replace your existing applications with a Software-as-a-Service (SaaS) solution. This strategy is suitable when current applications are outdated or lack the scalability offered by the cloud.
  
• Rehost (Lift and Shift): This approach involves moving your applications to the cloud without making any changes. It’s a straightforward “lift and shift” migration that helps you quickly take advantage of cloud infrastructure while keeping the application architecture intact.
  
• Relocate: Similar to rehosting, this strategy involves moving applications at the hypervisor level. The main difference is that it may involve more in-depth infrastructure management and might be better suited for specific environments.
  
• Replatform: In this strategy, you migrate your applications to the cloud as they are but make certain changes to optimize them for cloud-native features. For example, you might switch to a managed database service or adjust the way the application is deployed to take advantage of cloud features.
  
• Refactor: This strategy involves re-architecting your Java application to fully leverage cloud-native capabilities. It’s ideal for businesses looking to modernize their applications for better scalability, performance, and cost-effectiveness on AWS.

During migration, ensure that all components (application code, databases, files, etc.) are properly moved and configured. Use AWS migration tools like AWS Application Migration Service for seamless migration.

Use Case Example:
If you’re running a Spring Boot app with an internal MySQL DB, a Replatform approach using Elastic Beanstalk + Amazon RDS may offer the fastest path to modernization without major code rewrites.

Step 6: Validate the Migration

After you migrate your Java application, validate its integrity and behavior in the AWS environment:

• Use CloudWatch Dashboards to track key metrics in real time.
• Perform end-to-end QA and UAT testing.
• Check database replication accuracy and data consistency.
• Monitor for latency spikes, error rates, and CPU/memory usage.

Step 7: Optimize and Scale the Application

Post-migration, it’s time to tune for performance and cost-efficiency:

• Consider moving static assets to Amazon S3 and dynamic routing with API Gateway.
• Right-size EC2 instances or use Auto Scaling groups.
• Enable Elastic Load Balancing and Amazon CloudFront for faster delivery.
• Set budgets and usage alerts with AWS Cost Explorer.

Step 8: Set Up Monitoring and Maintenance

Ensure your application remains performant and secure long-term:

• Set up a DevOps pipeline for continuous delivery and rollback.
• Use Amazon CloudWatch Alarms to detect anomalies.
• Automate updates, backup schedules, and patch management.
• Continuously monitor traffic, response times, and cost patterns.

By following these steps, you can successfully migrate your Java applications to AWS Cloud, gaining the benefits of scalability, flexibility, and cost efficiency while ensuring a smooth transition with minimal disruption to your business operations.

Pro Tip
Start with a pilot migration of a non-critical Java app. It lets you validate your toolchain, train your team, and test rollback plans—before scaling to mission-critical systems.

Handling Challenges in Migration

Java application migration to AWS can present challenges such as application compatibility, data migration complexity, cost management, security, and downtime. To handle these:

1. Application Compatibility

Older Java versions or monolithic architectures may not run optimally on cloud-native environments.

• Solution:
  • Test in a staging environment that mirrors production.
  • Update deprecated APIs, middleware, or outdated libraries before full deployment.

2. Data Migration Complexity

Database schema differences, latency, and data loss risks can arise during migration.

• Solution:
  • Use AWS Database Migration Service (DMS) to handle large datasets with minimal downtime.
  • Perform pre- and post-migration validation to ensure data consistency.

3. Cost Visibility and Control

Unexpected costs can emerge from over-provisioned instances or idle resources.

• Solution:
  • Monitor spending using AWS Cost Explorer.
  • Set budgets and configure alerts to manage resource utilization efficiently.

4. Security and Compliance

Java apps that process sensitive data must adhere to compliance frameworks (e.g., HIPAA, GDPR).

• Solution:
  • Use AWS IAM for access control and AWS KMS for encryption management.
  • Implement least privilege access and regularly audit credentials.

5. Downtime and Business Disruption

Extended downtime affects user experience and business continuity.

• Solution:
  • Use incremental migration to move components gradually.
  • Establish clear rollback plans and communicate changes with stakeholders.

By addressing these challenges early, you can ensure a more efficient and secure migration to AWS.

Also Read: AWS Cost Optimization: Benefits, Best Practices & Tools

Wrapping Up

Migrating Java applications to AWS Cloud brings key benefits like improved scalability, cost savings, and better performance. With proper planning, the right AWS services, and strategies for tackling compatibility and downtime, your migration will be smooth and successful. 

Whether you’re rehosting, re-platforming, or refactoring, AWS has the tools to modernize and optimize your Java workloads for better business outcomes and efficiency.

At CrossAsyst, we provide expert guidance and customized AWS solutions to help you achieve your goals faster. We work alongside your team to craft strategies that fit your business needs, ensuring seamless migration and optimization. Our approach focuses on collaboration, knowledge sharing, and empowering your team for success.

Ready to make the most of your cloud journey? Contact us today!

Reference:

• Grand View Reasearch
• MARKETSANDMARKETS