SUMMARY

• 9+ years of experience in software development for J2EE web - based applications
• Proven track record of coding, integrating complex technical processes within international, high-profile and tight deadline-oriented environments.
• Extensive experience in Java J2EE technologies using Core Java, Java collection, JDBC, Threads, Spring Framework, Struts Framework, Hibernate, Servlets, DHTML, CSS, JMS, JSTL, Display Tag (Custom Tag), Ajax, Java Script.
• Extensive experience of working on all tiers of J2EE n-tier Architecture.
• Proficient in designing applications using Java and J2EE Design Patterns such as Singleton, Factory, Facade, Observer, Command Patterns, Value/Data Transfer etc.
• Good web page design skills using HTML, CSS, Java Script, AJAX, and XML.
• Extensive Knowledge in Java Persistence API.
• Exposure to Software Engineering methodology like Agile methodology, Waterfall methodology.
• Responsible for coding, implementation and unit testing of various J2EE related projects.
• Worked on EJB (stateless Session, MDB, and Entity Beans).
• Extensive experience in Tomcat Server, Jboss, Web logic and Websphere application servers
• Good Experience in implementing Web Services such as SOAP, WSDL, UDDI.
• Extensive experience in database designing using RDBMS Concepts in Oracle, MS SQL.
• Hands-on experience in writing stored procedures, functions, views, triggers and joins.
• Knowledge on all the AWS components like VPC, EC2, ELB, Auto Scaling, launch Configurations, S3, Glacier, Lifecycle rules for storage, Route 53, Cloud watch, Cloud Trial, RedShift, Volume and Snapshot management, SNS, IAM and Roles.
• Good working knowledge of NoSQL Database, MongoDB.
• Worked on Service Oriented Architecture (SOA) such as Apache Axis web services, uses SOAP, WSDL. Exposure to JAXB & JAX-WS & JAX-RS.
• Experience with Application Servers like IBM Websphere 6.x/5.x/7.0, Oracle/BEA WebLogic9.x/8.x/7.x/6.x, Jboss and Tomcat.
• Performed Cloning of Web Logic and OFSAA.

TECHNICAL SKILLS

• J2EE, deadline-oriented environments, Core Java, Java collection, JDBC, Threads, Spring Framework, Struts Framework
• Hibernate, Servlets, DHTML, CSS, JMS, JSTL, Display Tag (Custom Tag), Ajax, Java Script, Singleton, Factory, Facade
• Observer, Command Patterns, HTML, CSS, Java Script, AJAX, XML, Java Persistence API, Tomcat Server, Jboss
• Web logic, SOAP, WSDL, MS SQL, VPC, EC2, ELB, Auto Scaling, S3, Glacier, Cloud watch, Cloud Trial, RedShift
• MongoDB, Service Oriented Architecture (SOA), Apache Axis, JAXB, OFSAA

PROFESSIONAL EXPERIENCE

Confidential, San Francisco, California

Sr. Java/J2EE Developer

Responsibilities:

• Developed applications using the latest Java/ J2EE technologies and worked with the latest features of Java 11+.
• Work with Advanced Java 11+ features like Lambda, filters and Predicates for adding functionality processing capability and Stream API to facilitate pipeline processing and method to eliminate elements based on the criteria.
• Design and development of J2EE and Spring Framework with Spring core modules and MVC architecture using Java 11+.
• Created different kinds of data reports from same collection of data using Java 11+ Collections Streams and Filters features.
• Worked on configuration of development environment using Spring Boot 2.2 with Spring MVC, Spring Data, Prime faces.
• Spring Modules (DAO, MVC, Securities, AOP, ORM data) - Developed DAOs using JPA entity manager and JTA for transaction handling
• Implemented the Model View Controller (MVC) framework and spring.
• Used Single Sign-On (SSO) with Spring Security in multi-tiered client web applications for User authentication to use one login feature.
• Good experience on Spring Core, Spring AOP, and Spring ORM concepts and implementation.
• Implemented functionalities using Spring IO / Spring Boot with Thymeleaf and Hibernate ORM.
• Developed micro services using Spring Boot JPA to fetch the data from the DB
• Build Restful web services with Spring Boot, Spring MVC, Spring Data rest and Hibernate
• Worked with Java and Quarkus to develop the APIs to interact with each other
• Implemented Micro services using Spring Boot and Micronaut frameworks.
• Extensive experience in ORM/JPA using Hibernate, JPA Toplink, EJB3.
• Implemented Hibernate 5.x to interact with Oracle 11g database.
• Developed applications using Hibernate Criteria ORM mappings using xml and annotation configurations.
• Implemented JavaScript validation frame work for client side & server side.
• Designed and developed the Presentation layer using Angular 9 and Material Design for Boot strap.
• Developed and maintained Geospatial user interfaces in React.js 16.
• Created Reusable components(with AJAX components) in Wicket Frame Work
• Built HTML/CSS prototypes to test usability, browser rendering behavior and performance, accessibility and mobile responsiveness.
• Designed and implemented database structure in MySQL Server.
• Migrated the production MySQL schema to the new AWS RDS Aurora instance.
• Developed modules to use Spring/Ibatis to communicate with Oracle database.
• Developed Servlets and Worked extensively on Sql.
• Worked on PL/SQL and SQL queries.
• Designed and implemented the MongoDB Schema and used document references to query data.
• Monitored SQL server performance using profiler to find performance and deadlocks.
• Design, develop and test of SOA services using SOA / Web Service / Oracle Fusion Middleware.
• Architected and implement REST api interfaces using JavaScript and Node.js.
• Worked on web service calls, XML and JSON parsing included in the project.
• Made strategies for Authentication, Authorization and log formats for AT&T standard internal components with OAuth and passport.js using secure gateway.
• Implemented JWT (JSON Web Tokens) for creating tokens to assert claims in the application and thus providing authentication of Restful services.
• Performed application development using tools like IntelliJ, JUNIT, and Maven for building application.
• Used VS Code as an Integrated Development Environment (IDE) with Java Plugins.
• Used Maven to build and deploy application JAR into Jboss WildFly server.
• Configured Git repositories in GitHub for the Android development team.
• Used Swagger for API documentation and check the API functionality and response without effecting the source code.
• Developed unit tests with JUNIT 5 and Mockito
• Created test coverage for the web services by using JUnit and Easy mock.
• Performed bug tracking and Unit Testing using JUnit, TestNG and Find Bugs.
• Performed load testing using JMeter and developed Java code to improve performance.
• Performed Service Level Testing for Web services using Soap UI, Postman and Apigee.
• Installed and configured Sonar Qube in the dev server for Code analysis and integrated Sonar plug-in in out Gradle build and Jenkins.
• Designed and implemented four Agile Scrum teams for product development.
• Excelled as Scrum Master, Scrum Coach, and Trainer, demonstrating proficiency.
• Implemented a Continuous Delivery framework using Maven, Jenkins and Chef in Linux environment
• Implemented Multi-Threaded Services for Robot using Gradle.
• Analyzed business requirements and documented them into business stories in JIRA.
• Integrate the third-party applications using Drools.
• Implemented micro services architecture by splitting business functions into reusable services.
• Created and implemented a design to use Apache Camel and JMS to establish communication between broker CRM and Plans Data Source.
• Developed Spring Jms Component for Connecting to active MQ and push the messages into ActiveMQ.
• Designed the real-time analytics and ingestion platform using Storm and Kafka.
• Deployed the developed web components on Apache Tomcat Web-Server.
• Developed shell scripts, on Linux platform, to process data from upstream systems that were scheduled to be executed at specific times by Autosys.
• Automated project requests by writing Perl and Unix Shell scripts.
• Worked on Installation and setup in Mac and Windows as required of the frameworks Cordova, Xamarin, Appcelerator, and Native Script.
• Used SOLID principles to maintain and extend over time of the application.
• Worked on a redesign of existing learning some application using domain driven design and dependency injection framework.
• (Inversion of Control), Single Responsibility design and many others to build extensible and easily testable applications.
• Worked on gang of four technologies to develop an application.
• Developed reusable composite components using Prime faces API that can be used across all the pages.
• Wrote maintainable code including extensive behavioral testing and version control, including CircleCI, bug testing and peer review standards.
• Created Java proxy services for SOA services from to call from external Java classes.
• Implemented reusable visual design elements and used Abstract to grab assets out of mockups and optimized them for the web
• Developed prototype using frameworks such as Storybook, Material-UI, Style guide-components & NextJS.
• Implemented Singleton Service Locator design patterns in Cairngorm MVC architecture to interact with backend.
• Created Angular Services using factory services to implement the business logic.
• Deployed and monitor scalable infrastructure on Amazon web services (AWS) configuration management using Puppet and Ansible.
• Managed Ubuntu Linux and Windows virtual servers on AWS EC2 using Puppet.
• Implemented the AWS S3 infrastructure for Big Data environment for data analytics.
• Configured and consume data in AWS RDS and in-memory database by writing various types of SQL scripts and manipulate the files stored and retrieved in AWS S3.
• Developed API Gateway using Node.js and Used MongoDB as a Database for storing information.
• Used Nginx as load balancer to pass requests to node.js server with the cors.
• Configured Elastic Load Balancers with EC2 Auto scaling groups.
• Used DynamoDB to store data on AWS server.
• Established automated build and deployment processes with CircleCI, Heroku, and Dockers
• Used Kubernetes to deploy scale, load balance, and manage Dockers containers with multiple namespace versions.
• Docker’s deployment with help of ECS clusters pulling images from private ECR.
• Created monitoring plan using AWS Cloud Watch and Sensu monitoring tool.
• Migrated and managing multiple applications from on premise to cloud (IaaS, PaaS, SaaS, ITaaS) using AWS services like S3, SES, VPC.
• Worked on Blend4Web, AWS SNS/SQS, Three.js and O3D based high level API extensively.
• Worked with Elastic search and other Big Data Science libraries such as Pandas, Numpy and Data frames.
• Configured Kinesis Shards for optimal throughput in Kinesis Streams for Spark Streaming Applications on AWS
• Automated the ingestion of data from source systems into Hadoop, and from Hadoop into Vertica.
• Worked on AWS Data Pipeline to configure data loads from S3 to into Red shift.
• Developed flows / orchestrations for integrating the components written on top of different internal platforms using Mule ESB and ActiveMQ.
• Deployed website with AWS Elastic Beanstalk environment and connected to domain using Route 53 record sets.
• Created functions and assigned roles in AWS Lambda to run python scripts, and AWS Lambda using java to perform event driven processing.
• Delivered high quality modules on the AWS stack using Lambda, SNS and Elastic cache with Redis
• Used Jenkins Code Deploy plug-in to deploy to AWS.
• Establishing SSO between SAP Portal and SharePoint using SAML
• Planned and Implemented SSL encryption for MongoDB intra-cluster communications.
• Automated provisioning of infrastructure and applications on Azure for DevOps environment

Environment: Java 11+, Spring boot 2.2, Spring Modules (DAO, MVC, Securities, AOP, ORM data), Thymeleaf, Spring boot JPA, Spring Data rest, Quarkus, micronaut, JPA Toplink, Hibernate 5.x, Hibernate Criteria, JavaScript, Angular 9, React.js 16, AJAX, HTML/CSS, MySQL, Oracle, SQL, PL/SQL, MongoDB, Profiler, SOA, Rest, JSON, OAUTH, JWT, IntelliJ, VS codeJboss Wildly, Git, Swagger, JUnit 5, Easy Mock, TestNG, JMeter, Postman, Sonar Qube, Agile, Scrum, Maven, Gradle, JIRA, drools / mvel, Micro services, JMS, ActiveMQ, Kafka, Tomcat, Linux, Unix, Mac, solid principles, domain driven design, single responsibility design, gang of four, composite, behavioral, proxy, abstract, prototype, singleton, factory, AWS, EC2, S3, RDS, API Gateway, Load Balancer, auto scaling, DynamoDB, Dockers, Kubernetes, ECS, Cloud watch, SES, SQS, SNS, elastic search, kinesis, Hadoop, data pipeline, message broker ActiveMQ, elastic beanstalk, lambda, elastic Cache, code deploy, SSO, SSL, azure.

Confidential, Philadelphia, PA

Sr. Java/J2EE Developer

Responsibilities:

• Experienced in Java 8 features like Lambda Expressions, Java Stream API and Concurrent Accumulators.
• Used Java 8 diamond operators, Java stream API, Collection Api and Lambda expressions etc.
• Worked on Java 8, Lambda expressions (for code optimization and improved performance).
• Designed and developed Auto-Tester tool using Java 8.
• Wrote varies DAO layers and spring service Controllers for handling data and request to Spring, Implemented DAO layer using Hibernate.
• Solid experience with Model View Controller (MVC) architecture based Web Application Development.
• Experience in working with Python ORM Libraries including Django ORM.
• Implemented Data Access Layer using JDBC Connections and IBATIS.
• Developed data insertion forms and validated them using JavaScript.
• Created diagrams, wireframes, and HTML/CSS prototypes and Wrote use cases, UI specifications and a UI Style Guide.
• Developed the administrative UI using Backbone.js and Marionette.js.
• Deployed application using Heroku and its Postgres add-on.
• Worked in PostgreSQL database on simple queries and writing Stored Procedures for normalization and denormalization.
• Migrated the production SQL server schema to the new AWS RDS Aurora instance.
• Worked on Restful API and invoked web services (consumed) that are based on EJBs.
• Developed numerous web applications using Java, SQL, Spring Data, JSON and JQuery.
• Used Spring Security for OAuth authentication, by configuring Spring Security into Spring MVC application.
• Created and consumed web services using JSON, XML, and REST.
• Developed client facing User interfaces using Eclipse RCP to interact with Apollo Server.
• Used Spring Tool Suite as IDE and log4j along with Log back framework to implement logging for the project.
• Installed and configured IBM Websphere Application Server on Linux,AIX,Solaris platforms.
• Utilized Git version control tool as the source control management system.
• Used SVN version controller to manage code versions and to check in the data as XML files.
• Created test coverage for the web services by using JUnit and Easy mock.
• Wrote JUnit test cases and used Mockito for mocking service calls.
• Used SoapUI and JMeter to check load balancing in Web Logic with multi thread and to check accounts.
• Utilized Postman services to check the API's created using Loopback NodeJS framework.
• Integrated SonarQube with Jenkins to track code coverage before move deployment of tag to production.
• Developed performance report by following BDD and Agile.
• Experience in full life cycle (SDLC) of software development and in Agile Methodology and Scrum meetings.
• Conducted version control, software maintenance and backup using Maven and Git.
• Migrated Jira across environments and worked on Jira database MYSQL dumps.
• Design and development of BPM processes using Bizflow process studio as BPM tool and Java script as scripting language.
• Wrote Entity validation rules and kyc validation rules using ILOG JRules.
• Defined and Created SOA software and hardware infrastructure, including Application Servers, Services Bus, Server Domains.
• Developed JMS components to send messages from one application to other application using Apache ActiveMQ.
• Developed business rules using Jboss drools and ActiveMQ and enabled the team to write business rules for some of the APIs using kie workbench.
• Involved in deploying the application in Tomcat 5.0 web server.
• Deployed the applications in Linux servers using deployment scripts.
• Implemented Code (Perl/Unix Shell scripts) and writing unit test cases for the same.
• Built an installer plug-in for Appcelerator installer on Mac using Objective-C.
• Created hybrid cloud by combining private cloud and public cloud (using Amazon web services) and used it for public scaling.
• Create and maintain Amazon EC2 instance that supports the companies Red mine project management site and Mercurial CM.
• Implemented AWS solutions using E2C, S3, RDS, Auto-scaling groups.
• Built application and database servers using AWS EC2 and use RDS for Oracle DB.
• Configured, supported and maintained all network, load balancers, operating systems, and software in AWS EC2.
• Built scripts on AWS cloud for scheduling EC2 auto scaling load balancer with python sdk.
• Implemented AWS solutions using DynamoDB, EBS, and Elastic Load Balancer.
• Configured custom metrics for the AWS Cloud Watch for detailed monitoring.
• Used the Amazon SES API to integrate the functionality of Amazon SES directly into applications.
• Used Amazon SQS (Simple Queue Service) to manage the interactions between different micro-services.
• Delivered high quality modules on the AWS stack using Lambda, SNS and Elastic ache with Redis
• Code and developed custom Elastic Search Java based wrapper client using the "Jest" API.
• Developed JMS components to send messages from one application to other application using Apache ActiveMQ.
• Installed the Apache Kafka cluster and Confluent Kafka open source in different environments.

Environment: Java 8, Spring Modules (DAO, MVC, ORM), Ibatis, JavaScript, HTML/CSS, Backbone js, Postgres, PostgreSQL, SQL server, Restful API, JSON, OAUTH, XML, Eclipse, Spring tools, websphere, Git, SVN, JUnit, Mockito, JMeter, Postman, Sonar Qube, Agile, Scrum, Maven, JIRA, BPM, Ilog, SOA, JMS, ActiveMQ, Tomcat, Linux, Unix, Mac.

Confidential, Louisville, KY

Sr. Java/J2EE Developer

Responsibilities:

• Application enhancement/maintenance in Java 6 using Spring MVC framework and JDBC at the database layer.
• Backend solutions designed with Java 6/REST API architecture.
• Used the fundamentals of Java 6 like parallel streams and filters through lambda expressions to handle the searching.
• Developed the application using Java 6 and implemented its features like lambdas Expressions, Time API, Streams, type interfaces, for each.
• Worked on spring application framework features IOC container and AOP.
• Implemented Java based POJO access to the application's Oracle 11g database using Mybatis.
• Created and modified services following micro service architecture using Java, spring and Struts 2.3.
• Developed web-based customer management software using Face lets, Ice faces and JSF.
• Responsible for writing and implementation of JavaScript, AJAX and JQuery to interact with web Services and user controls.
• Developed the front-end in HTML/CSS including Bootstrap and Vue.js.
• Designed and developed DB2 SQL Procedures and UNIX Shell Scripts for Data Import/Export and Conversions.
• Migrated data from Oracle database from a LINUX environment to MS SQL server using ODBC driver.
• Architected and implement REST API interfaces using JavaScript and Node.js.
• Designed and implemented XML parsing for XML order conformations.
• Constructed the JAXRS web services using Apache CXF backend calling the spring framework services.
• Used Eclipse IDE for Java and XML development and QA and branched projects using Tortoise SVN.
• Installed and configured of Apache, Web logic for QA Environment.
• Worked with SVN to manage source code repositories and performed branching, merging, and tagging depending on requirement.
• Developed JUnit test cases for unit testing and Mockito for mocking.
• Performance test cases with the JMeter and functional test suites as BDD with the Cucumber JVM.
• Used REST Client and POSTMAN to test the rest based services.
• Developed and tested many features in AGILE environment using HTML5, CSS3, JavaScript, Bootstrap, Rspec.
• Developed the Front end application using JSP and HTML.
• Responsible in creating Servlets, which route submittals to appropriate Enterprise Java Bean (EJB) components and render, retrieved information.
• Developed OSGI bundles and sling Services using Maven in Eclipse.
• Established ANT and scripts for build activities MAVEN in QA, Staging and Production environments.
• Created JSON based Azure Resource Manager (ARM) templates for deployments.
• Worked on JIRA development with JAVA and Groovy scripting.
• Developed Interfaces for applications connecting to IBM Ilog JRules through Web services and deployed in Apache Tomcat.
• Developed SOA composites which involved in database, File and JMS integrations using DB Adapter, JMS Adapter and File Adapter.
• Created war files & deployed on Tomcat using ANT deployment tool.
• Installed and configured IBM Websphere Application Server on Linux, AIX, Solaris platforms.
• Developed Application that would allow transfer of log files from Linux (Debian) computer to Linux server using C++ multithreading environment.
• Automated Unix Shell Scripts to Schedule ETL Work flows within Informatica Power center.
• Created Mac OS images using Casper (JAMF,JSS) imaging tools (Mavericks)
• Built a website using Amazon Web Services (AWS) with PHP, MySQL.
• Responsible for maintaining and expanding our AWS infrastructure using AWS EC2, manage documents in S3, providing IAM access to S3 buckets.
• Worked on moving the production SQL server blueprint to the new AWS RDS Aurora instance.

Environment: Java6, Spring, Mybatis, Struts 2.3,JSF, JavaScript, HTML/CSS, Db2, MS SQL, Rest, XML, Apache CXF, Eclipse, web logic, SVN, JUnit, JMeter, Postman, Agile, JSP, Servlets, Maven, ANT, JSON, JIRA, JRules, SOA, Tomcat, Websphere, Linux, Unix, Mac, AWS, EC2, S3, RDS, AWS, EC2, S3, RDS, Load Balancer, auto scaling, DynamoDB, Cloud watch, SES, SQS, SNS, elastic search, message broker ActiveMQ, Kafka.

Confidential, San Jose, CA

Java Developer

Responsibilities:

• Used java 5 features like stream, Lambda expressions, functional interface, collections, Date/Time changes and type annotations.
• Used Streams and Lambda expressions available as part of Java 5 to store and process the data.
• Strong coding skills with Java 5, Spring IOC, Spring Boot, Spring Data-RS, Hibernate framework.
• Used Java 5 Lambdas to make anonymous inline function calls and used Streams to work effectively with Collection objects.
• Developed business components using spring and hibernate.
• Developed the Presentation and Controller layers using JSP and Struts.
• Used the JDBC for data retrieval from the database for various inquiries.
• Implemented View layer of MVC architecture using JSF components.
• Used JavaScript for developing UI Components like Editable drop down, data-driven menu customizations.
• Use HTML/CSS and JavaScript to implement front end experiments via Adobe Target.
• Integrate Oracle Coherence with Oracle Web Center.
• Developed Web Services to communicate to other modules using XML based SOAP and WSDL protocols.
• Developed Rest architecture based web services to facilitate communication between client and servers.
• Wrote Web services using Apache Axis2 and generated the WSDL.
• Used NetBeans as IDE tool to develop the applications and Jira for bug and issue tracking.
• Extensively used IBM Websphere Portal APIs for authentication and personalization features.
• Involved in the configuration management using Eclipse, CVS and GitHub.
• Developed JUnit test cases for all the developed modules.
• Worked on different software development methodologies like Waterfall, use cases, Spiral, RUP and Agile Process.
• Responsible for developing GUI / user interfaces using JSP, CSS & DHTML.
• Designed JavaServlets and Objects using J2EE standards.
• Developed ANT scripts to build and deploy the application in the JBOSS Application Server.
• Used Stylus Studio for modifying XSL style sheets to help generate XML documents.
• Implemented WSDL XML document to located and describe the web services.
• Created JIRA Support Project/Agile board to track support issues.
• Involved in migration of code from Web sphere server dependent to tomcat server.
• Used Google App Engine cloud services to launch Linux and windows machines.
• Created directory structure flow using UNIX to receive and send data to internal and external systems.
• Used Amazon Web Services (AWS) to maintain a centralized storage for server hosted on two boxes.
• Configured QA environment using AWS EC2, RDS, and Route53 services.
• Used AWS S3 to store code bundles to deploy onto EC2 Instances.
• Created AWS RDS and mapping the EC2 JBOSS configurations to point to AWS RDS instance.

Environment: Java 5, Spring, Struts, JDBC, JSF, JavaScript, HTML/CSS, Oracle, SOAP, Rest, Axis2, NetBeans, websphere, CVS, JUnit, Waterfall, JSP, Servlets, ANT, XML, WSDL, JIRA, Tomcat, Linux, Unix, AWS, EC2, S3, RDS.

Confidential, Hartford, CT

Java Developer

Responsibilities:

• Analysis, design and development of Application based on J2EE and Design Patterns.
• Used the Struts framework for managing the navigation and page flow.
• Created templates using design patterns Business Delegate, Service Locator, Session Faade extensively.
• Developed the EJB - Session Bean acts as Faade, will be able to access the business entities through their local home interfaces.
• Used JDBC for accessing the data from the DB2 database.
• Worked on Registration, Recovery and Service contracts modules.
• Studied Detail design document and designed class and sequence diagrams using Rational Rose.
• Used forward engineering approach to create skeleton classes from class diagrams.
• Followed architectural standards and coded Request Handlers, BO, DAO, SQL Helper classes.
• Involved in writing complex stored procedures, prepare statements.
• Used Java Servlets extensively and using JDBC for database access
• Using JavaScript performed client side validations on Registration module.
• Coded JSPs, Servlets and implementation logic for BO, DAO.
• Used Struts MVC at front end. Server side validations were performed using Struts validation framework.
• Coded test cases for the developed classes using JUNIT framework.
• Documented developed modules.
• Provided support for Production and Implementation Issues.
• Involved in end-user/client training of the application.
• Involved in the release management process to QA/UAT/Production regions.

Environment: J2EE, Java 1.2, EJB2.0, Java Beans, JDBC, JSP, Struts1.0, Design Patterns, BEA Web Logic 7.1, PL/SQL, DB2, UML, agile, WinCVS, JUnit, Log4j.