Lambda expressions, default methods in interfaces, and the new date/time API are among the major new features in Java 8. Lambda expressions allow for functional-style programming by treating functionality as a method argument or anonymous implementation. Default methods add new capabilities to interfaces while maintaining backwards compatibility. The date/time API improves on the old Calendar and Date APIs by providing immutable and easier to use classes like LocalDate.
Java is Object Oriented Programming. Java 8 is the latest version of the Java which is used by many companies for the development in many areas. Mobile, Web, Standalone applications.
Presentation provides introduction and detailed explanation of the Java 8 Lambda and Streams. Lambda covers with Method references, default methods and Streams covers with stream operations,types of streams, collectors. Also streams are elaborated with parallel streams and benchmarking comparison of sequential and parallel streams.
Additional slides are covered with Optional, Splitators, certain projects based on lambda and streams
Java 8 is coming soon. In this presentation I have outlined the major Java 8 features. You get information about interface improvements, functional interfaces, method references, lambdas, java.util.function, java.util.stream
In Java 8, the java.util.function has numerous built-in interfaces. Other packages in the Java library (notably java.util.stream package) make use of the interfaces defined in this package. Java 8 developers should be familiar with using key interfaces provided in this package. This presentation provides an overview of four key functional interfaces (Consumer, Supplier, Function, and Predicate) provided in this package.
Java is Object Oriented Programming. Java 8 is the latest version of the Java which is used by many companies for the development in many areas. Mobile, Web, Standalone applications.
Presentation provides introduction and detailed explanation of the Java 8 Lambda and Streams. Lambda covers with Method references, default methods and Streams covers with stream operations,types of streams, collectors. Also streams are elaborated with parallel streams and benchmarking comparison of sequential and parallel streams.
Additional slides are covered with Optional, Splitators, certain projects based on lambda and streams
Java 8 is coming soon. In this presentation I have outlined the major Java 8 features. You get information about interface improvements, functional interfaces, method references, lambdas, java.util.function, java.util.stream
In Java 8, the java.util.function has numerous built-in interfaces. Other packages in the Java library (notably java.util.stream package) make use of the interfaces defined in this package. Java 8 developers should be familiar with using key interfaces provided in this package. This presentation provides an overview of four key functional interfaces (Consumer, Supplier, Function, and Predicate) provided in this package.
In this Meetup Victor Perepelitsky - R&D Technical Leader at LivePerson leading the 'Real Time Event Processing Platform' team , will talk about Java 8', 'Stream API', 'Lambda', and 'Method reference'.
Victor will clarify what functional programming is and how can you use java 8 in order to create better software.
Victor will also cover some pain points that Java 8 did not solve regarding functionality and see how you can work around it.
This is a beginner's guide to Java 8 Lambdas, accompnied with executable code examples which you can find at https://github.com/manvendrasinghkadam/java8streams. Java 8 Streams are based on Lambdas, so this presentation assumes you know Lambdas quite well. If don't then please let me know I'll create another presentation regarding it with code examples. Lambdas are relatively easy to use and with the power of stream api you can do functional programming in Java right from start. This is very cool to be a Java programmer now.
This is a basic tutorial on Spring core.
Best viewed when animations and transitions are supported, e.g., view in MS Powerpoint. So, please try to view it with animation else the main purpose of this presentation will be defeated.
Overview of Spring Boot for the rapid development of Java Applications and Microservices. More information can be found at : https://www.spiraltrain.nl/course-spring-boot-development/?lang=en
Welcome to presentation on Spring boot which is really great and relatively a new project from Spring.io. Its aim is to simplify creating new spring framework based projects and unify their configurations by applying some conventions. This convention over configuration is already successfully applied in so called modern web based frameworks like Grails, Django, Play framework, Rails etc.
Start programming in a more functional style in Java. This is the second in a two part series on lambdas and streams in Java 8 presented at the JoziJug.
Slides for a lightning talk on Java 8 lambda expressions I gave at the Near Infinity (www.nearinfinity.com) 2013 spring conference.
The associated sample code is on GitHub at https://github.com/sleberknight/java8-lambda-samples
Introduction to the Spring Framework:
Generar description
IoC container
Dependency Injection
Beans scope and lifecycle
Autowiring
XML and annotation based configuration
Additional features
Presentation on the new features introduced in JDK 8, presented on the 26.02.2013 in Sofia University in front of students and members of the Bulgarian java user group.
In this Meetup Victor Perepelitsky - R&D Technical Leader at LivePerson leading the 'Real Time Event Processing Platform' team , will talk about Java 8', 'Stream API', 'Lambda', and 'Method reference'.
Victor will clarify what functional programming is and how can you use java 8 in order to create better software.
Victor will also cover some pain points that Java 8 did not solve regarding functionality and see how you can work around it.
This is a beginner's guide to Java 8 Lambdas, accompnied with executable code examples which you can find at https://github.com/manvendrasinghkadam/java8streams. Java 8 Streams are based on Lambdas, so this presentation assumes you know Lambdas quite well. If don't then please let me know I'll create another presentation regarding it with code examples. Lambdas are relatively easy to use and with the power of stream api you can do functional programming in Java right from start. This is very cool to be a Java programmer now.
This is a basic tutorial on Spring core.
Best viewed when animations and transitions are supported, e.g., view in MS Powerpoint. So, please try to view it with animation else the main purpose of this presentation will be defeated.
Overview of Spring Boot for the rapid development of Java Applications and Microservices. More information can be found at : https://www.spiraltrain.nl/course-spring-boot-development/?lang=en
Welcome to presentation on Spring boot which is really great and relatively a new project from Spring.io. Its aim is to simplify creating new spring framework based projects and unify their configurations by applying some conventions. This convention over configuration is already successfully applied in so called modern web based frameworks like Grails, Django, Play framework, Rails etc.
Start programming in a more functional style in Java. This is the second in a two part series on lambdas and streams in Java 8 presented at the JoziJug.
Slides for a lightning talk on Java 8 lambda expressions I gave at the Near Infinity (www.nearinfinity.com) 2013 spring conference.
The associated sample code is on GitHub at https://github.com/sleberknight/java8-lambda-samples
Introduction to the Spring Framework:
Generar description
IoC container
Dependency Injection
Beans scope and lifecycle
Autowiring
XML and annotation based configuration
Additional features
Presentation on the new features introduced in JDK 8, presented on the 26.02.2013 in Sofia University in front of students and members of the Bulgarian java user group.
OCP Java (OCPJP) 8 Exam Quick Reference CardHari kiran G
If you are preparing to appear for Oracle Certified Professional Java SE 8 Programmer (OCPJP 8) certification exam, this a reference card (sort of long cheat sheet) meant to help you. You may want to print this reference card for your easy and quick reference when you prepare for your exam.
This presentation provides an overview of oracle's associate and professional Java certifications - gives you ideas on how to prepare and crack the exam with ease.
Functional Thinking - Programming with Lambdas in Java 8Ganesh Samarthyam
Functional programming is on the rise. Almost all major and mainstream languages support functional programming features, including C++, Java, Swift, and Python, and Visual Basic. With Java 8’s lambda functions, Java now supports functional programming. Moving to functional programming can result in significantly better code and productivity gains. However, it requires a paradigm shift: you need to move away from imperative and object-oriented thinking to start thinking functionally. That’s what this workshop will help you achieve: it will help you make your shift towards functional programming. The workshop will introduce lambda functions in Java with examples from Java library itself. Presented in OSI Days 2015 workshop - http://osidays.com/osidays/shifting-to-functional-programming-lambdas-for-java-developers/
Let us explore Java 8 features and start using it in your day to day work. You will be surprised how Java has evolved to become so different yet easy & powerful. In this presentation, we discuss Java 8 Stream API.
Supercharged java 8 : with cyclops-reactJohn McClean
Overview of the rationale behind cyclops-react and some of it's features, including extended Java Collections, more powerful Sequential and Parallel Streaming, pattern matching, data types (such as Xor cyclops-react Either type, Maybe, Eval).
This presentaion provides and overview of the new features of Java 8, namely default methods, functional interfaces, lambdas, method references, streams and Optional vs NullPointerException.
This presentation by Arkadii Tetelman (Lead Software Engineer, GlobalLogic) was delivered at Java.io 3.0 conference in Kharkiv on March 22, 2016.
Cover Basic concept for Functional Programming in Java. Define new functional interfaces, lambda expressions, how to translate lambda expression, JVM deal with new byte code etc. This is not the perfect slides for functional programming, but trying cover simple basic functional programming.
Automatic Migration of Legacy Java Method Implementations to InterfacesRaffi Khatchadourian
Java 8 is one of the largest upgrades to the popular language and framework in over a decade. In this talk, I will first overview several new, key features of Java 8 that can help make programs easier to read, write, and maintain, especially in regards to collections. These features include Lambda Expressions, the Stream API, and enhanced interfaces, many of which help bridge the gap between functional and imperative programming paradigms and allow for succinct concurrency implementations. Next, I will discuss several open issues related to automatically migrating (refactoring) legacy Java software to use such features correctly, efficiently, and as completely as possible. Solving these problems will help developers to maximally understand and adopt these new features thus improving their software.
Java 8 is one of the largest upgrades to the popular language and framework in over a decade. This talk will detail several new key features of Java 8 that can help make programs easier to read, write, and maintain. Java 8 comes with many features, especially related to collection libraries. We will cover such new features as Lambda Expressions, the Stream API, enhanced interfaces, and more.
State of ICS and IoT Cyber Threat Landscape Report 2024 previewPrayukth K V
The IoT and OT threat landscape report has been prepared by the Threat Research Team at Sectrio using data from Sectrio, cyber threat intelligence farming facilities spread across over 85 cities around the world. In addition, Sectrio also runs AI-based advanced threat and payload engagement facilities that serve as sinks to attract and engage sophisticated threat actors, and newer malware including new variants and latent threats that are at an earlier stage of development.
The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties – USA
Expansion of bot farms – how, where, and why
In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
Axis of attacks – Europe
Systemic attacks in the Middle East
Download the full report from here:
https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
PHP Frameworks: I want to break free (IPC Berlin 2024)Ralf Eggert
In this presentation, we examine the challenges and limitations of relying too heavily on PHP frameworks in web development. We discuss the history of PHP and its frameworks to understand how this dependence has evolved. The focus will be on providing concrete tips and strategies to reduce reliance on these frameworks, based on real-world examples and practical considerations. The goal is to equip developers with the skills and knowledge to create more flexible and future-proof web applications. We'll explore the importance of maintaining autonomy in a rapidly changing tech landscape and how to make informed decisions in PHP development.
This talk is aimed at encouraging a more independent approach to using PHP frameworks, moving towards a more flexible and future-proof approach to PHP development.
Essentials of Automations: Optimizing FME Workflows with ParametersSafe Software
Are you looking to streamline your workflows and boost your projects’ efficiency? Do you find yourself searching for ways to add flexibility and control over your FME workflows? If so, you’re in the right place.
Join us for an insightful dive into the world of FME parameters, a critical element in optimizing workflow efficiency. This webinar marks the beginning of our three-part “Essentials of Automation” series. This first webinar is designed to equip you with the knowledge and skills to utilize parameters effectively: enhancing the flexibility, maintainability, and user control of your FME projects.
Here’s what you’ll gain:
- Essentials of FME Parameters: Understand the pivotal role of parameters, including Reader/Writer, Transformer, User, and FME Flow categories. Discover how they are the key to unlocking automation and optimization within your workflows.
- Practical Applications in FME Form: Delve into key user parameter types including choice, connections, and file URLs. Allow users to control how a workflow runs, making your workflows more reusable. Learn to import values and deliver the best user experience for your workflows while enhancing accuracy.
- Optimization Strategies in FME Flow: Explore the creation and strategic deployment of parameters in FME Flow, including the use of deployment and geometry parameters, to maximize workflow efficiency.
- Pro Tips for Success: Gain insights on parameterizing connections and leveraging new features like Conditional Visibility for clarity and simplicity.
We’ll wrap up with a glimpse into future webinars, followed by a Q&A session to address your specific questions surrounding this topic.
Don’t miss this opportunity to elevate your FME expertise and drive your projects to new heights of efficiency.
JMeter webinar - integration with InfluxDB and GrafanaRTTS
Watch this recorded webinar about real-time monitoring of application performance. See how to integrate Apache JMeter, the open-source leader in performance testing, with InfluxDB, the open-source time-series database, and Grafana, the open-source analytics and visualization application.
In this webinar, we will review the benefits of leveraging InfluxDB and Grafana when executing load tests and demonstrate how these tools are used to visualize performance metrics.
Length: 30 minutes
Session Overview
-------------------------------------------
During this webinar, we will cover the following topics while demonstrating the integrations of JMeter, InfluxDB and Grafana:
- What out-of-the-box solutions are available for real-time monitoring JMeter tests?
- What are the benefits of integrating InfluxDB and Grafana into the load testing stack?
- Which features are provided by Grafana?
- Demonstration of InfluxDB and Grafana using a practice web application
To view the webinar recording, go to:
https://www.rttsweb.com/jmeter-integration-webinar
UiPath Test Automation using UiPath Test Suite series, part 4DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 4. In this session, we will cover Test Manager overview along with SAP heatmap.
The UiPath Test Manager overview with SAP heatmap webinar offers a concise yet comprehensive exploration of the role of a Test Manager within SAP environments, coupled with the utilization of heatmaps for effective testing strategies.
Participants will gain insights into the responsibilities, challenges, and best practices associated with test management in SAP projects. Additionally, the webinar delves into the significance of heatmaps as a visual aid for identifying testing priorities, areas of risk, and resource allocation within SAP landscapes. Through this session, attendees can expect to enhance their understanding of test management principles while learning practical approaches to optimize testing processes in SAP environments using heatmap visualization techniques
What will you get from this session?
1. Insights into SAP testing best practices
2. Heatmap utilization for testing
3. Optimization of testing processes
4. Demo
Topics covered:
Execution from the test manager
Orchestrator execution result
Defect reporting
SAP heatmap example with demo
Speaker:
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Let's dive deeper into the world of ODC! Ricardo Alves (OutSystems) will join us to tell all about the new Data Fabric. After that, Sezen de Bruijn (OutSystems) will get into the details on how to best design a sturdy architecture within ODC.
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.
Software Delivery At the Speed of AI: Inflectra Invests In AI-Powered QualityInflectra
In this insightful webinar, Inflectra explores how artificial intelligence (AI) is transforming software development and testing. Discover how AI-powered tools are revolutionizing every stage of the software development lifecycle (SDLC), from design and prototyping to testing, deployment, and monitoring.
Learn about:
• The Future of Testing: How AI is shifting testing towards verification, analysis, and higher-level skills, while reducing repetitive tasks.
• Test Automation: How AI-powered test case generation, optimization, and self-healing tests are making testing more efficient and effective.
• Visual Testing: Explore the emerging capabilities of AI in visual testing and how it's set to revolutionize UI verification.
• Inflectra's AI Solutions: See demonstrations of Inflectra's cutting-edge AI tools like the ChatGPT plugin and Azure Open AI platform, designed to streamline your testing process.
Whether you're a developer, tester, or QA professional, this webinar will give you valuable insights into how AI is shaping the future of software delivery.
Connector Corner: Automate dynamic content and events by pushing a buttonDianaGray10
Here is something new! In our next Connector Corner webinar, we will demonstrate how you can use a single workflow to:
Create a campaign using Mailchimp with merge tags/fields
Send an interactive Slack channel message (using buttons)
Have the message received by managers and peers along with a test email for review
But there’s more:
In a second workflow supporting the same use case, you’ll see:
Your campaign sent to target colleagues for approval
If the “Approve” button is clicked, a Jira/Zendesk ticket is created for the marketing design team
But—if the “Reject” button is pushed, colleagues will be alerted via Slack message
Join us to learn more about this new, human-in-the-loop capability, brought to you by Integration Service connectors.
And...
Speakers:
Akshay Agnihotri, Product Manager
Charlie Greenberg, Host
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.
2. Agenda
❖ New Features in Java language
➢ Lambda Expression
➢ Functional Interface
➢ Interface’s default and Static Methods
➢ Method References
❖ New Features in Java libraries
➢ Stream API
➢ Date/Time API
4. ❖ Unnamed block of code (or an unnamed
function) with a list of formal parameters and
a body.
✓ Concise
✓ Anonymous
✓ Function
✓ Passed around
Lambda Expression
6. Example 1:
Comparator<Person> byAge = new Comparator<Person>(){
public int compare(Person p1, Person p2){
return p1.getAge().compareTo(p2.getAge());
}
};
Lambda Expression
Example 2:
JButton testButton = new JButton("Test Button");
testButton.addActionListener(new ActionListener(){
@Override public void actionPerformed(ActionEvent ae){
System.out.println(“Hello Anonymous inner class");
}
});
7. Example 1: with lambda
Comparator<Person> byAge =
(Person p1, Person p2) -> p1.getAge().compareTo(p2.getAge());
Lambda Expression
Example 2: with lambda
testButton.addActionListener(e -> System.out.println(“Hello
Lambda"));
9. (Person p1, Person p2) -> p1.getAge().compareTo(p2.getAge());
Lambda Expression
Lambda parameters Lambda body
Arrow
The basic syntax of a lambda is either
(parameters) -> expression
or
(parameters) -> { statements; }
10. ❖ Lambda does not have:
✓ Name
✓ Return type
✓ Throws clause
✓ Type parameters
Lambda Expression
12. Variable scope:
public void printNumber(int x) {
int y = 2;
Runnable r = () -> System.out.println(“Total is:” + (x+y));
new Thread(r).start();
}
Lambda Expression
Free variable: not define in lambda parameters.
Variable scope:
public void printNumber(int x) {
int y = 2;
Runnable r = () ->{System.out.println(“Total is:” + (x+y));
System.out.println(this.toString());};
new Thread(r).start();
}
Not allow:
public void printNumber(int x) {
int y = 2;
Runnable r = () -> {
x++;//compile error
System.out.println(“Total is:” + (x+y))
};
}
25. ● Brand new java.util.function package.
● Rich set of function interfaces.
● 4 categories:
o Supplier
o Consumer
o Predicate
o Function
Add text here...
Functional Interface
26. ● Accept an object and return nothing.
● Can be implemented by lambda
expression.
Add text here...
Consumer Interface
28. Interface Default and Static
Methods
Add text here...
Interface Default and Static Methods
29. static <T> Collection<T>
synchronizedCollection(Collection<T
Interface Default and Static Methods
● Advantages:
- No longer need to provide your own companion utility classes. Instead, you
can place static methods in the appropriate interfaces
- Adding methods to an interface without breaking the existing
implementation
java.util.Collections
java.util.Collection
● Extends interface declarations with two new concepts:
- Default methods
- Static methods
31. Default methods
● Classes implement interface that contains a default method
❏ Not override the default method and will inherit the default method
❏ Override the default method similar to other methods we override in
subclass
❏ Redeclare default method as abstract, which force subclass to override it
32. Default methods
● Solve the conflict when the same method declare in interface or
class
- Method of Superclasses, if a superclass provides a concrete
method.
- If a superinterface provides a default method, and another
interface supplies a method with the same name and
parameter types (default or not), then you must overriding that
method.
33. Static methods
● Similar to default methods except that we can’t override
them in the implementation classes
35. Method References
● Method reference is an important feature related to
lambda expressions. In order to that a method
reference requires a target type context that consists of
a compatible functional interface
36. Method References
● There are four kinds of method references:
- Reference to a static method
- Reference to an instance method of a particular object
- Reference to an instance method of an arbitrary object
of a particular type
- Reference to a constructor
52. // get even numbers
evenNumbers.forEach(i ->
System.out.println(i));
/* Console output
* 2
* 4
* 6
* 8
*/
Add text here...
Stream - forEach()
53. Converting stream to list
List<Integer> numbers =
evenNumbers.collect(Collectors.toList());
Converting stream to array
Integer[] numbers =
evenNumbers.toArray(Integer[]::new);
Add text here...
Stream - Converting to collections
55. What’s new in Date/Time?
Add text here...
Date / Time
56. ● Why do we need a new Date/Time API?
Add text here...
Date / Time
○ Objects are not immutable
○ Naming
○ Months are zero-based
57. ● LocalDate
Add text here...
Date / Time
○ A LocalDate is a date, with a year,
month, and day of the month
LocalDate today = LocalDate.now();
LocalDate christmas2015 = LocalDate.of(2015, 12, 25);
LocalDate christmas2015 = LocalDate.of(2015,
Month.DECEMBER, 25);
58. Java 7:
Calendar c = Calendar.getInstance();
c.add(Calendar.DATE, 1);
Date dt = c.getTime();
Java 8:
LocalDate tomorrow = LocalDate.now().plusDay(1);
Add text here...
Date / Time
59. ● Temporal adjuster
Add text here...
Date / Time
LocalDate nextPayDay = LocalDate.now()
.with(TemporalAdjusters.lastDayOfMonth());
60. ● Create your own adjuster
TemporalAdjuster NEXT_WORKDAY = w -> {
LocalDate result = (LocalDate) w;
do {
result = result.plusDays(1);
} while (result.getDayOfWeek().getValue() >= 6);
return result;
};
LocalDate backToWork = today.with(NEXT_WORKDAY);
Add text here...
Date / Time
62. Add text here...
References
❖ Java Platform Standard Edition 8 Documentation,
(http://docs.oracle.com/javase/8/docs/)
❖ Java 8 In Action, Raoul-Gabriel Urma, Mario Fusco, and Alan Mycroft.
❖ Beginning Java 8 Language Features, Kishori Sharan.
❖ What’s new in Java 8 - Pluralsight
The code is quite not elegant and not easy to read.
Anonymous classes use a bulky syntax. Lambda expressions
use a very concise syntax to achieve the same result.
The body of a lambda expression is a block of code enclosed in braces. Like
a method's body, the body of a lambda expression may declare local variables; use statements including break,
continue, and return; throw exceptions, etc.
A lambda expression does not have a name.
A lambda expression does not have a throws clause. It is inferred from the context of its use
and its body.
A lambda expression cannot declare type parameters. That is, a lambda expression cannot be generic
A lambda expression does not have a explicit return type. It is auto recognized by the compiler from the context of its use and from its body.
Accessing outer scope variables from lambda expressions is very similar to anonymous objects. You can access final variables from the local outer scope as well as instance fields and static variables
So where exactly can you use lambdas? You can use a lambda expression in the context of a
functional interface. Don’t worry if this sounds abstract; we now explain in detail what this means and what a functional interface
is.
Functional Interface is a new term of Java 8
The functional interface is an normal interface with only one abstract method.
Take a look at the example here, the well-known Runnable and Comparator interface are now become functional interface, so what we can see here that the term of functional interface is new but all the interfaces back from previous Java versions are becoming functional interface without any needed of modification.
When we count the abstract method from an interface to check if it’s functional interface or not. The methods from Object class don’t count.
Why some methods of the Object class sometimes are added to an interface? But most of the time and this is the reason because someone would like to redeclared methods from Object class in the interface in order to extend comments from Object’s class in order to give some special semantic and to add javadoc that might be different from Object class.
http://grepcode.com/file_/repository.grepcode.com/java/root/jdk/openjdk/6-b14/java/util/Comparator.java/?v=source
By the default, the compiler of Java will automatically check if interface is a functional interface or not.
But for convenience, the functional interface can be annotated inside the code.
It can be annotated by adding @FunctionalInterface on the top of the interface like the example below.
By doing so, the IDE will help you to detect if it is a functional interface before compiler do its job.
In this example, I declared another abstract method in the functional interface and as you can see, with the annotation, the IDE will check and show an error message that this interface is not a functional interface. So you can immediately notice and correct the problem.
With the new term of functional interface defined in java 8.
It also includes a brand new sets of functional interfaces.
All these functional interfaces are defined in new package named java.util.function.
It contains around 43 interfaces and grouped into 4 categories as I listed below: Supplier, consumer, predicate, function.
You will see and use it a lot when you working with Java 8 and lambda expression.
In the scope of this presentation I will not go and explain for every interfaces. Instead, I will pick one of them to give you an example.
Classes implement interface that contains a default method, they can perform following:
- Not override the default method and will inherit the default method- Override the default method similar to other methods we override in subclass- Redeclare default method as abstract, which force subclass to override it
Classes implement interface that contains a default method, they can perform following:
- Not override the default method and will inherit the default method- Override the default method similar to other methods we override in subclass- Redeclare default method as abstract, which force subclass to override it
Let’s talk about why the stream is efficient.
Nowaday, most of computer are using multiple CPUs, so we will take advantages of that to the stream in order to process data parallelly.
Let’s talk about why the stream is efficient.
Nowaday, most of computer are using multiple CPUs, so we will take advantages of that to the stream in order to process data parallelly.
Intermediate operations return the stream itself so you can chain multiple method calls in a row. Let’s learn important ones.
Intermediate operations return the stream itself so you can chain multiple method calls in a row. Let’s learn important ones.
Terminal operations return a result of a certain type instead of again a Stream.
Intermediate operations return the stream itself so you can chain multiple method calls in a row. Let’s learn important ones.
Intermediate operations return the stream itself so you can chain multiple method calls in a row. Let’s learn important ones.
statefull
Date is not a date, but a timestamp, Calendar is mix of dates and times…
have to work with Joda API. But there still have problem with the performance…
this new API is base on Joda and was implemented by joda team