CDI (Contexts and Dependency Injection) is the Java standard for dependency injection and interception. It simplifies and standardizes the API for DI and AOP similar to how JPA did for ORM. CDI uses annotations like @Inject and @Produces to manage dependencies between classes and allows for features like interceptors and decorators. While part of Java EE, CDI can also be used outside of a Java EE container.
Java Annotation is quite a handy tool and has the ample potential to make developer's life a lot easier(and exciting!). Learning and using custom Java Annotation Processor takes the power of Annotation even a class higher. This slide goes over a few fundamental things of an Annotation Processor to get someone started to write his/her own Annotation Processor in Java.
Key topics are,
- Java Annotation
- Usage of Annotation
- Custom Java Annotation
- Java Annotation Processor
- Usefulness of Annotation Processor
- Dive into the core of Annotation Processor
- Solve a validation problem with Custom Annotation Processor
- Get to know some exciting Annotation Processing tools that already exist
Introduction to Annotations.
What are Annotations➔ Annotations are structured information added to program source code➔ Annotations associated meta-information with definitions➔ They can be attached to any variable, method, expression, or another program element Like comments, they can be sprinkled throughout a program➔ Unlike comments, they have structure, thus making them easier to machine process.
Java Annotation is quite a handy tool and has the ample potential to make developer's life a lot easier(and exciting!). Learning and using custom Java Annotation Processor takes the power of Annotation even a class higher. This slide goes over a few fundamental things of an Annotation Processor to get someone started to write his/her own Annotation Processor in Java.
Key topics are,
- Java Annotation
- Usage of Annotation
- Custom Java Annotation
- Java Annotation Processor
- Usefulness of Annotation Processor
- Dive into the core of Annotation Processor
- Solve a validation problem with Custom Annotation Processor
- Get to know some exciting Annotation Processing tools that already exist
Introduction to Annotations.
What are Annotations➔ Annotations are structured information added to program source code➔ Annotations associated meta-information with definitions➔ They can be attached to any variable, method, expression, or another program element Like comments, they can be sprinkled throughout a program➔ Unlike comments, they have structure, thus making them easier to machine process.
Java agents and their instrumentation API offer developers the most powerful toolset to interact with a Java application. Using this API, it becomes possible to alter the code of running applications, for example to add monitoring or to inject security checks as it is done by many enterprise products for the Java ecosystem.
In this session, developers will learn how to program Java agents of their own that make use of the instrumentation API. Doing so, developers learn how the majority of tooling for the JVM is implemented and will learn about Byte Buddy, a high level code generation library that does not require any knowledge of Java byte code that is normally required for writing agents. In the process, developers will see how Java classes can be used as templates for implementing highly performant code changes that avoid the boilerplate of alternative solutions such as AspectJ or Javassist while still performing better than agents implemented in low-level libraries such as ASM.
micro(-service) components. While this approach to building software - if done correctly - can improve a system's maintainability and scalability, distributed applications also introduce challanges for operations. Where monolithic applications typically offered direct access to extensive monitoring dashbords, such easy overview is no longer available when multitude services are loosly connected over a network. But how to keep track of a system of such dynamic state?
Distributed tracing is a method of connecting interaction of different services on a network. Collecting and processing such tracing information again allows for the observation of a distributed system in its entirety. This talk shares the presenter's insights gained by working on the JVM-support of distributed tracing for the APM tool Instana. Doing so, it introduces the landscape of distributed tracing on the JVM, discussing popular approaches such as Dapper, Zipkin or Brave/OpenTracing. In the process, it is discussed how byte code instrumentation can be used to capture systems without requiring a user to set up the software under observation. The presentation finishes with a discussion of typical problems of distributed tracing solutions and carefully examines the performance penalties APM tools entail.
Java 9 introduces modules to the Java programming language and its runtime. Despite this feature being optional, due to the modularization of the standard library existing applications might behave differently when running on a version 9 JVM. Furthermore, because of changes in the runtime, existing libraries and frameworks might not yet correctly process your modularized code. As a result, updating to a Java 9 VM and taking Java 9 into brings its challanges.
This talk discusses the practical implications of module boundaries and analyzes new limitations Java 9 imposes on the reflection API. This talk explains how reflection is used in popular frameworks like Spring and Hibernate and explains why existing applications might break or change their behavior when facing modularized code. Finally, this talk showcases alternatives to now failing Java programming patterns and weights their robustness with regard to the Java releases 10 and upward.
The presenter is an active contributor to open source and helped to migrate many popular Java libraries to supporting Java 9. As a consequence, he as been working with Java 9 for almost two years.
Remote Method Invocation, Distributed Programming in java, Java Distributed Programming, Network Programming in JAVA, Core Java, Introduction to RMI, Getting Started with RMI, Getting Started with Remote Method Invocation, Distributed Programming, Java, J2SE
While most bugs reveal their cause within their stack trace, Java’s OutOfMemoryError is less talkative and therefore regarded as being difficult to debug by a majority of developers. With the right techniques and tools, memory leaks in Java programs can however be tackled like any other programming error. This talks discusses how a JVM stores data, categorizes different types of memory leaks that can occur in a Java program and presents techniques for fixing such errors. Furthermore, we will have a closer look at lambda expressions and their considerable potential of introducing memory leaks when they are used incautiously.
Introduction to java beans, java beans, Core java, j2se, getting started with java beans programming, java to standard edition, beans in java, beans programming in java
Spring Certification Questions and Spring Free test are tests created to demonstrate all the functions of our mock exams. You will be able to access ten full questions and will have ten minutes of time for finishing the test.
There are several components you can interact with when you take our mock exams:
Take a look at the progress bar at the top; it will tell how you are progressing through the exam.
Read the question and select only the answers you think are correct by checking the corresponding check box.
Navigate the spring questions using the "Previous" and "Next" buttons.
Mark the spring questions you wish to review later. All the questions you have marked will be listed on the right in the section "marked questions". You will be able to jump directly to the question from this list.
If you want to take a look at the correct answers for a question, just click the "Solution" button. In the solution section you will be able to check your answers as well as find a full explanation of the question.
Keep an eye on the countdown. This will tell you how much time is remaining. When the countdown expires, the test will be automatically submitted.
Once the test is submitted, the "result" section will expand. Here, you will be able to review all the questions of the test. From here, you can also navigate directly to each question.
This session will give attendees an overview of the new testing features in Spring 3.1 as well the new Spring MVC test support. Sam Brannen will demonstrate how to use the Spring TestContext Framework to write integration tests for Java-based Spring configuration using @Configuration classes. He'll then compare and contrast this approach with XML-based configuration and follow up with a discussion of the new testing support for bean definition profiles. Next, Rossen Stoyanchev will show attendees how testing server-side code with annotated controllers and client-side code with the RestTemplate just got a whole lot easier with the new Spring MVC test support. Come to this session to see these new Spring testing features in action and learn how you can get involved in the Spring MVC Test Support project.
Java agents and their instrumentation API offer developers the most powerful toolset to interact with a Java application. Using this API, it becomes possible to alter the code of running applications, for example to add monitoring or to inject security checks as it is done by many enterprise products for the Java ecosystem.
In this session, developers will learn how to program Java agents of their own that make use of the instrumentation API. Doing so, developers learn how the majority of tooling for the JVM is implemented and will learn about Byte Buddy, a high level code generation library that does not require any knowledge of Java byte code that is normally required for writing agents. In the process, developers will see how Java classes can be used as templates for implementing highly performant code changes that avoid the boilerplate of alternative solutions such as AspectJ or Javassist while still performing better than agents implemented in low-level libraries such as ASM.
micro(-service) components. While this approach to building software - if done correctly - can improve a system's maintainability and scalability, distributed applications also introduce challanges for operations. Where monolithic applications typically offered direct access to extensive monitoring dashbords, such easy overview is no longer available when multitude services are loosly connected over a network. But how to keep track of a system of such dynamic state?
Distributed tracing is a method of connecting interaction of different services on a network. Collecting and processing such tracing information again allows for the observation of a distributed system in its entirety. This talk shares the presenter's insights gained by working on the JVM-support of distributed tracing for the APM tool Instana. Doing so, it introduces the landscape of distributed tracing on the JVM, discussing popular approaches such as Dapper, Zipkin or Brave/OpenTracing. In the process, it is discussed how byte code instrumentation can be used to capture systems without requiring a user to set up the software under observation. The presentation finishes with a discussion of typical problems of distributed tracing solutions and carefully examines the performance penalties APM tools entail.
Java 9 introduces modules to the Java programming language and its runtime. Despite this feature being optional, due to the modularization of the standard library existing applications might behave differently when running on a version 9 JVM. Furthermore, because of changes in the runtime, existing libraries and frameworks might not yet correctly process your modularized code. As a result, updating to a Java 9 VM and taking Java 9 into brings its challanges.
This talk discusses the practical implications of module boundaries and analyzes new limitations Java 9 imposes on the reflection API. This talk explains how reflection is used in popular frameworks like Spring and Hibernate and explains why existing applications might break or change their behavior when facing modularized code. Finally, this talk showcases alternatives to now failing Java programming patterns and weights their robustness with regard to the Java releases 10 and upward.
The presenter is an active contributor to open source and helped to migrate many popular Java libraries to supporting Java 9. As a consequence, he as been working with Java 9 for almost two years.
Remote Method Invocation, Distributed Programming in java, Java Distributed Programming, Network Programming in JAVA, Core Java, Introduction to RMI, Getting Started with RMI, Getting Started with Remote Method Invocation, Distributed Programming, Java, J2SE
While most bugs reveal their cause within their stack trace, Java’s OutOfMemoryError is less talkative and therefore regarded as being difficult to debug by a majority of developers. With the right techniques and tools, memory leaks in Java programs can however be tackled like any other programming error. This talks discusses how a JVM stores data, categorizes different types of memory leaks that can occur in a Java program and presents techniques for fixing such errors. Furthermore, we will have a closer look at lambda expressions and their considerable potential of introducing memory leaks when they are used incautiously.
Introduction to java beans, java beans, Core java, j2se, getting started with java beans programming, java to standard edition, beans in java, beans programming in java
Spring Certification Questions and Spring Free test are tests created to demonstrate all the functions of our mock exams. You will be able to access ten full questions and will have ten minutes of time for finishing the test.
There are several components you can interact with when you take our mock exams:
Take a look at the progress bar at the top; it will tell how you are progressing through the exam.
Read the question and select only the answers you think are correct by checking the corresponding check box.
Navigate the spring questions using the "Previous" and "Next" buttons.
Mark the spring questions you wish to review later. All the questions you have marked will be listed on the right in the section "marked questions". You will be able to jump directly to the question from this list.
If you want to take a look at the correct answers for a question, just click the "Solution" button. In the solution section you will be able to check your answers as well as find a full explanation of the question.
Keep an eye on the countdown. This will tell you how much time is remaining. When the countdown expires, the test will be automatically submitted.
Once the test is submitted, the "result" section will expand. Here, you will be able to review all the questions of the test. From here, you can also navigate directly to each question.
This session will give attendees an overview of the new testing features in Spring 3.1 as well the new Spring MVC test support. Sam Brannen will demonstrate how to use the Spring TestContext Framework to write integration tests for Java-based Spring configuration using @Configuration classes. He'll then compare and contrast this approach with XML-based configuration and follow up with a discussion of the new testing support for bean definition profiles. Next, Rossen Stoyanchev will show attendees how testing server-side code with annotated controllers and client-side code with the RestTemplate just got a whole lot easier with the new Spring MVC test support. Come to this session to see these new Spring testing features in action and learn how you can get involved in the Spring MVC Test Support project.
Back-2-Basics: .NET Coding Standards For The Real World (2011)David McCarter
Revamped for 2011 (90% new material), this session will guide any level of programmer to greater productivity by providing the information needed to write consistent, maintainable code. Learn about project setup, assembly layout, code style, defensive programming and much, much more. Code tips are included to help you write better, error free applications. Lots of code examples in C# and VB.NET. This session is based off my latest book, David McCarter's .NET Coding Standards.
A class is the blueprint from which individual objects are created. In the real world, you'll often find many individual objects all of the same kind. Each bicycle was built from the same set of blueprints and therefore contains the same components. In object-oriented terms, we say that your bicycle is an instance of the class of objects known as bicycles.
Kotlin is a modern programming language that focuses on clarity, code safety and conciseness. Google officially adopted Kotlin by adding support into Android Studio in 2017 and since then has announced it as the preferred language for Android developers. Android app teams have incrementally added Kotlin code to their projects or have elected to start new Android projects in Kotlin moving forward. Having the app code and UI automation code in the same language helps engineering and QA teams level set on the critical user journeys being tested. Here we share the basics of getting started with automating an Appium test in Kotlin.
Generic programming is a style of computer programming in which algorithms are written in terms of types to-be-specified-later that are then instantiated when needed for specific types provided as parameters.
Generics are a facility of generic programming that were added to the Java programming language in 2004 within version J2SE 5.0. They were designed to extend Java's type system to allow “a type or method to operate on objects of various types while providing compile-time type safety”
The Java collections framework supports generics to specify the type of objects stored in a collection instance.
UiPath Test Automation using UiPath Test Suite series, part 5DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 5. In this session, we will cover CI/CD with devops.
Topics covered:
CI/CD with in UiPath
End-to-end overview of CI/CD pipeline with Azure devops
Speaker:
Lyndsey Byblow, Test Suite Sales Engineer @ UiPath, Inc.
Essentials of Automations: The Art of Triggers and Actions in FMESafe Software
In this second installment of our Essentials of Automations webinar series, we’ll explore the landscape of triggers and actions, guiding you through the nuances of authoring and adapting workspaces for seamless automations. Gain an understanding of the full spectrum of triggers and actions available in FME, empowering you to enhance your workspaces for efficient automation.
We’ll kick things off by showcasing the most commonly used event-based triggers, introducing you to various automation workflows like manual triggers, schedules, directory watchers, and more. Plus, see how these elements play out in real scenarios.
Whether you’re tweaking your current setup or building from the ground up, this session will arm you with the tools and insights needed to transform your FME usage into a powerhouse of productivity. Join us to discover effective strategies that simplify complex processes, enhancing your productivity and transforming your data management practices with FME. Let’s turn complexity into clarity and make your workspaces work wonders!
Observability Concepts EVERY Developer Should Know -- DeveloperWeek Europe.pdfPaige Cruz
Monitoring and observability aren’t traditionally found in software curriculums and many of us cobble this knowledge together from whatever vendor or ecosystem we were first introduced to and whatever is a part of your current company’s observability stack.
While the dev and ops silo continues to crumble….many organizations still relegate monitoring & observability as the purview of ops, infra and SRE teams. This is a mistake - achieving a highly observable system requires collaboration up and down the stack.
I, a former op, would like to extend an invitation to all application developers to join the observability party will share these foundational concepts to build on:
Removing Uninteresting Bytes in Software FuzzingAftab Hussain
Imagine a world where software fuzzing, the process of mutating bytes in test seeds to uncover hidden and erroneous program behaviors, becomes faster and more effective. A lot depends on the initial seeds, which can significantly dictate the trajectory of a fuzzing campaign, particularly in terms of how long it takes to uncover interesting behaviour in your code. We introduce DIAR, a technique designed to speedup fuzzing campaigns by pinpointing and eliminating those uninteresting bytes in the seeds. Picture this: instead of wasting valuable resources on meaningless mutations in large, bloated seeds, DIAR removes the unnecessary bytes, streamlining the entire process.
In this work, we equipped AFL, a popular fuzzer, with DIAR and examined two critical Linux libraries -- Libxml's xmllint, a tool for parsing xml documents, and Binutil's readelf, an essential debugging and security analysis command-line tool used to display detailed information about ELF (Executable and Linkable Format). Our preliminary results show that AFL+DIAR does not only discover new paths more quickly but also achieves higher coverage overall. This work thus showcases how starting with lean and optimized seeds can lead to faster, more comprehensive fuzzing campaigns -- and DIAR helps you find such seeds.
- These are slides of the talk given at IEEE International Conference on Software Testing Verification and Validation Workshop, ICSTW 2022.
LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...DanBrown980551
Do you want to learn how to model and simulate an electrical network from scratch in under an hour?
Then welcome to this PowSyBl workshop, hosted by Rte, the French Transmission System Operator (TSO)!
During the webinar, you will discover the PowSyBl ecosystem as well as handle and study an electrical network through an interactive Python notebook.
PowSyBl is an open source project hosted by LF Energy, which offers a comprehensive set of features for electrical grid modelling and simulation. Among other advanced features, PowSyBl provides:
- A fully editable and extendable library for grid component modelling;
- Visualization tools to display your network;
- Grid simulation tools, such as power flows, security analyses (with or without remedial actions) and sensitivity analyses;
The framework is mostly written in Java, with a Python binding so that Python developers can access PowSyBl functionalities as well.
What you will learn during the webinar:
- For beginners: discover PowSyBl's functionalities through a quick general presentation and the notebook, without needing any expert coding skills;
- For advanced developers: master the skills to efficiently apply PowSyBl functionalities to your real-world scenarios.
Threats to mobile devices are more prevalent and increasing in scope and complexity. Users of mobile devices desire to take full advantage of the features
available on those devices, but many of the features provide convenience and capability but sacrifice security. This best practices guide outlines steps the users can take to better protect personal devices and information.
GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...James Anderson
Effective Application Security in Software Delivery lifecycle using Deployment Firewall and DBOM
The modern software delivery process (or the CI/CD process) includes many tools, distributed teams, open-source code, and cloud platforms. Constant focus on speed to release software to market, along with the traditional slow and manual security checks has caused gaps in continuous security as an important piece in the software supply chain. Today organizations feel more susceptible to external and internal cyber threats due to the vast attack surface in their applications supply chain and the lack of end-to-end governance and risk management.
The software team must secure its software delivery process to avoid vulnerability and security breaches. This needs to be achieved with existing tool chains and without extensive rework of the delivery processes. This talk will present strategies and techniques for providing visibility into the true risk of the existing vulnerabilities, preventing the introduction of security issues in the software, resolving vulnerabilities in production environments quickly, and capturing the deployment bill of materials (DBOM).
Speakers:
Bob Boule
Robert Boule is a technology enthusiast with PASSION for technology and making things work along with a knack for helping others understand how things work. He comes with around 20 years of solution engineering experience in application security, software continuous delivery, and SaaS platforms. He is known for his dynamic presentations in CI/CD and application security integrated in software delivery lifecycle.
Gopinath Rebala
Gopinath Rebala is the CTO of OpsMx, where he has overall responsibility for the machine learning and data processing architectures for Secure Software Delivery. Gopi also has a strong connection with our customers, leading design and architecture for strategic implementations. Gopi is a frequent speaker and well-known leader in continuous delivery and integrating security into software delivery.
DevOps and Testing slides at DASA ConnectKari Kakkonen
My and Rik Marselis slides at 30.5.2024 DASA Connect conference. We discuss about what is testing, then what is agile testing and finally what is Testing in DevOps. Finally we had lovely workshop with the participants trying to find out different ways to think about quality and testing in different parts of the DevOps infinity loop.
Alt. GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using ...James Anderson
Effective Application Security in Software Delivery lifecycle using Deployment Firewall and DBOM
The modern software delivery process (or the CI/CD process) includes many tools, distributed teams, open-source code, and cloud platforms. Constant focus on speed to release software to market, along with the traditional slow and manual security checks has caused gaps in continuous security as an important piece in the software supply chain. Today organizations feel more susceptible to external and internal cyber threats due to the vast attack surface in their applications supply chain and the lack of end-to-end governance and risk management.
The software team must secure its software delivery process to avoid vulnerability and security breaches. This needs to be achieved with existing tool chains and without extensive rework of the delivery processes. This talk will present strategies and techniques for providing visibility into the true risk of the existing vulnerabilities, preventing the introduction of security issues in the software, resolving vulnerabilities in production environments quickly, and capturing the deployment bill of materials (DBOM).
Speakers:
Bob Boule
Robert Boule is a technology enthusiast with PASSION for technology and making things work along with a knack for helping others understand how things work. He comes with around 20 years of solution engineering experience in application security, software continuous delivery, and SaaS platforms. He is known for his dynamic presentations in CI/CD and application security integrated in software delivery lifecycle.
Gopinath Rebala
Gopinath Rebala is the CTO of OpsMx, where he has overall responsibility for the machine learning and data processing architectures for Secure Software Delivery. Gopi also has a strong connection with our customers, leading design and architecture for strategic implementations. Gopi is a frequent speaker and well-known leader in continuous delivery and integrating security into software delivery.
How to Get CNIC Information System with Paksim Ga.pptxdanishmna97
Pakdata Cf is a groundbreaking system designed to streamline and facilitate access to CNIC information. This innovative platform leverages advanced technology to provide users with efficient and secure access to their CNIC details.
Unlocking Productivity: Leveraging the Potential of Copilot in Microsoft 365, a presentation by Christoforos Vlachos, Senior Solutions Manager – Modern Workplace, Uni Systems
Securing your Kubernetes cluster_ a step-by-step guide to success !KatiaHIMEUR1
Today, after several years of existence, an extremely active community and an ultra-dynamic ecosystem, Kubernetes has established itself as the de facto standard in container orchestration. Thanks to a wide range of managed services, it has never been so easy to set up a ready-to-use Kubernetes cluster.
However, this ease of use means that the subject of security in Kubernetes is often left for later, or even neglected. This exposes companies to significant risks.
In this talk, I'll show you step-by-step how to secure your Kubernetes cluster for greater peace of mind and reliability.
Pushing the limits of ePRTC: 100ns holdover for 100 daysAdtran
At WSTS 2024, Alon Stern explored the topic of parametric holdover and explained how recent research findings can be implemented in real-world PNT networks to achieve 100 nanoseconds of accuracy for up to 100 days.
Goodbye Windows 11: Make Way for Nitrux Linux 3.5.0!SOFTTECHHUB
As the digital landscape continually evolves, operating systems play a critical role in shaping user experiences and productivity. The launch of Nitrux Linux 3.5.0 marks a significant milestone, offering a robust alternative to traditional systems such as Windows 11. This article delves into the essence of Nitrux Linux 3.5.0, exploring its unique features, advantages, and how it stands as a compelling choice for both casual users and tech enthusiasts.
In his public lecture, Christian Timmerer provides insights into the fascinating history of video streaming, starting from its humble beginnings before YouTube to the groundbreaking technologies that now dominate platforms like Netflix and ORF ON. Timmerer also presents provocative contributions of his own that have significantly influenced the industry. He concludes by looking at future challenges and invites the audience to join in a discussion.
Generative AI Deep Dive: Advancing from Proof of Concept to ProductionAggregage
Join Maher Hanafi, VP of Engineering at Betterworks, in this new session where he'll share a practical framework to transform Gen AI prototypes into impactful products! He'll delve into the complexities of data collection and management, model selection and optimization, and ensuring security, scalability, and responsible use.
Maruthi Prithivirajan, Head of ASEAN & IN Solution Architecture, Neo4j
Get an inside look at the latest Neo4j innovations that enable relationship-driven intelligence at scale. Learn more about the newest cloud integrations and product enhancements that make Neo4j an essential choice for developers building apps with interconnected data and generative AI.
1. CDI Contexts and Dependency Injection CDI, formerly known as JSR 299, is an attempt at describing a true standard on Dependency Injection.
2. Introduction CDI is the Java standard for dependency injection (DI) and interception (AOP). CDI is similar to core Spring and Guice frameworks. Like JPA did for ORM, CDI simplifies and sanitizes the API for DI and AOP.
3. CDI to manage the dependencies CDI needs an bean.xml file to be in META-INF of your jar file or classpath or WEB-INF of your web application. This file can be completely empty. Use the @Inject annotation to annotate a setXXXsetter method in injected class
4. @Inject By default, CDI would look for a class that implements the ATMTransport interface, once it finds this it creates an instance and injects this instance of ATMTransport using the setter method setTransport. If we only had one possible instance of ATMTransport in our classpath, we would not need to annotate any of the ATMTransport implementations. Since we have three, namely, StandardAtmTransport, SoapAtmTransport, and JsonAtmTransport, we need to mark two of them as @Alternatives and one as @Default. public class AutomatedTellerMachineImpl implements AutomatedTellerMachine { private ATMTransport transport; @Inject public void setTransport(ATMTransport transport) { this.transport = transport; } } Using @Inject to inject via constructor args and fields @Inject public AutomatedTellerMachineImpl(ATMTransport transport) { this.transport = transport;}
5. @Default and @Alternative Use the @Default annotation to annotate the StandardAtmTransport @Defaultpublic class StandardAtmTransport implements ATMTransport{ Use the @Alternative to annotate the SoapAtmTransport, and JsonRestAtmTransport. @Alternativepublic class JsonRestAtmTransport implements ATMTransport {
6. @Named The @Named annotation is used by JEE 6 application to make the bean accessible via the Unified EL (EL stands for Expression language and it gets used by JSPs and JSF components). @Named("atm")public class AutomatedTellerMachineImpl implements AutomatedTellerMachine{ It should be noted that if you use the @Named annotations and don't provide a name, then the name is the name of the class with the first letter lower case so this: makes the name automatedTellerMachineImpl.
7. @Produces Instead of relying on a constructor, you can delegate to a factory class to create the instance. To do this with CDI, you would use the @Produces from your factory class as follows: public class TransportFactory{ @Produces ATMTransportcreateTransport() { System.out.println("ATMTransport created with producer"); return new StandardAtmTransport(); }} On calling @Inject private ATMTransport transport; it calls the factory method.
8. Defining @Alternative The @Alternative CDI annotation allows you to have multiple matching dependencies for a given injection point. This means you can define beans that provide implementations for the same interface without worrying about ambigious dependency errors. When you mark a class with the @Alternative annotation, it is effectively disabled and cannot be considered for injection. The only exception is for the class that is defined in the beans.xml configuration file. <beans xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaeehttp://java.sun.com/xml/ns/javaee/beans_1_0.xsd"> <alternatives> <class>org.cdi.advocacy.JsonRestAtmTransport </class> </alternatives> </beans> Once this bean is identified, it is then used in any injection point that matches for this bean. No other beans for similar injection points can be declared as the ‘active’ alternative.
9. @Qualifier All objects and producers in CDI have qualifiers. If you do not assign a qaulifier it by default has the qualifier @Default and @Any. You may decide that at times you want to inject Soap or Json or the Standard transport. You don't want to list them as an alternative. Qualifiers can be used to discriminate exaclty what gets injected. You can write custom qualifiers. @Qualifier @Retention(RUNTIME) @Target({TYPE, METHOD, FIELD, PARAMETER})public @interface Soap {} @Soappublic class SoapAtmTransport implements ATMTransport {
10. Injecting SoapAtmTransport using new @Soap qualifier via constructor arg @Inject public AutomatedTellerMachineImpl(@Soap ATMTransport transport) { this.transport = transport; } OR @Inject @Soapprivate ATMTransport transport;
11. Class uses two qualifiers @SuperFast @StandardFrameRelaySwitchingFlubberpublic class SuperFastAtmTransport implements ATMTransport { public void communicateWithBank(byte[] datapacket) { System.out.println("communicating with bank via the Super Fast transport " ); }} Usage : @Inject @SuperFast @StandardFrameRelaySwitchingFlubberprivate ATMTransport transport;
12. To solve Explosion of Qualifiers CDI allows you to discriminate on members of a qualifier to reduce the explosion of qualifiers. Instead of having three qualifier you could have one qualifier and an enum. Then if you need more types of transports, you only have to add an enum value instead of another class. Let's demonstrate how this works by creating a new qualifier annotation called Transport. The Transport qualifier annotation will have a single member, an enum called type. The type member will be an new enum that we define called TransportType. @Qualifier @Retention(RUNTIME) @Target({TYPE, METHOD, FIELD, PARAMETER})public @interface Transport { TransportType type() default TransportType.STANDARD;} public enumTransportType { JSON, SOAP, STANDARD;} Usage : @Transport(type=TransportType.SOAP)public class SoapAtmTransport implements ATMTransport { @Inject @Transport(type=TransportType.STANDARD)private ATMTransport transport;
13. Advanced: Using @Produces and InjectionPoint @Inject @TransportConfig(retries=2)private ATMTransport transport; @Produces ATMTransportcreateTransport(InjectionPointinjectionPoint) { Bean<?> bean = injectionPoint.getBean();TransportConfigtransportConfig = Bean.getBeanClass().getAnnotation (TransportConfig.class);StandardAtmTransport transport = new StandardAtmTransport(); transport.setRetries(transportConfig.retries());return transport; }
14. @Nonbinding Using @Nonbinding to combine a configuration annotation and a qualifier annotation into one annotation For e.g. - Transport qualifier annotation using @Nonbinding to add configuration retries param.
15. @Any @Any finds all of the transports in the system. Once you inject the instances into the system, you can use the select method of instance to query for a particular type. @Inject @Any private Instance<ATMTransport> allTransports; @PostConstruct protected void init() { transport = allTransports.select(new AnnotationLiteral<Default>(){}).get(); if (transport!=null) { System.out.println("Found standard transport"); return; } transport = allTransports.select(new AnnotationLiteral<Json>(){}).get(); if (transport!=null) { System.out.println("Found JSON standard transport"); return; } transport = allTransports.select(new AnnotationLiteral<Soap>(){}).get(); if (transport!=null) { System.out.println("Found SOAP standard transport"); return; }}
16. @Decorator Java EE 6 lets us create decorators through CDI, as part of their AOP features. If we want to implement cross cutting concerns that are still close enough to the business, we can use this feature of Java EE 6. @Decorator public class TicketServiceDecorator implements TicketService { @Inject @Delegate private TicketServiceticketService; @Inject private CateringServicecateringService; @Override public Ticket orderTicket(String name) { Ticket ticket = ticketService.orderTicket(name); cateringService.orderCatering(ticket); return ticket; } }
17. Injecting Java EE resources into a bean All managed beans may take advantage of Java EE component environment injection using @Resource, @EJB, @PersistenceContext, @PeristenceUnit, @PostConstruct and @PreDestroy and @WebServiceRef. Example : @Transactional @Interceptor public class TransactionInterceptor { @Resource UserTransaction transaction; @AroundInvoke public Object manageTransaction(InvocationContext ctx) throws Exception { ... } } @SessionScopedpublic class Login implements Serializable { @Inject Credentials credentials; @PersistenceContext EntityManager userDatabase; }
18. Dirty truth CDI is part of JEE 6. It could easily be used outside of a JEE 6 container. The problem is that there is no standard interface to use CDI outside of a JEE 6 container so the three main implementations Caucho Resin Candi, Red Hat JBoss Weld and Apache OpenWebBeans all have their own way to run a CDI container standalone.
19. Conclusion Dependency Injection (DI) refers to the process of supplying an external dependency to a software component. CDI is the Java standard for dependency injection and interception (AOP). It is evident from the popularity of DI and AOP that Java needs to address DI and AOP so that it can build other standards on top of it. DI and AOP are the foundation of many Java frameworks.