This document summarizes new features in Java 8, including lambda expressions, default methods on interfaces, streams, and performance improvements. Key additions are functional interfaces to support lambda expressions, new date/time and collections APIs, and the Nashorn JavaScript engine. The changes aim to enhance performance and usability.
These are Java ways of functional style; pragmatic ways of understanding and introducing Lambda/Functional API.
你可以在以下找到中文說明:
http://www.codedata.com.tw/java/jdk8-functional-api/
A framework for nonlinear model predictive controlModelon
This document presents a new framework for nonlinear model predictive control (MPC) in JModelica.org. MPC is an optimal control strategy that solves an optimal control problem repeatedly online to determine the optimal inputs. The new framework aims to improve the computational efficiency of MPC in JModelica.org by reusing information between optimizations. It discretizes the optimal control problem once, rather than at each iteration. In a benchmark of controlling a combined cycle power plant, the new MPC framework achieved similar control performance as the existing open-loop framework but was significantly faster, taking around 70% less total time. The MPC framework also makes the JModelica.org modeling environment easier to use for MPC applications.
This document provides a brief overview of Java 8 features including functional interfaces, lambda expressions, stream API, and Optional class. It discusses how functional interfaces provide target types for lambda expressions and can have a single abstract method. Lambda expressions allow implementing functional interfaces concisely without anonymous classes. The stream API provides a powerful way to process collections in a declarative way using lambda expressions. The Optional class avoids null pointer exceptions and allows chaining of method calls on objects that may be null.
This document discusses the development of a new framework for modeling multi-component multi-phase mixtures in Modelica. The goals are to support both native Modelica media implementations and connections to external thermophysical property databases, address limitations of the existing Modelica.Media interface, and enable new applications involving multi-phase processes. A model-based interface structure is proposed to overcome restrictions of using pure functions. An example demonstrates the approach for simulating air separation processes using both a simple native Modelica air media and a connection to Refprop. Further testing and development is still needed to fully realize the new framework.
BigDataSpain 2016: Stream Processing Applications with Apache ApexThomas Weise
Stream processing applications built on Apache Apex run on Hadoop clusters and typically power analytics use cases where availability, flexible scaling, high throughput, low latency and correctness are essential. These applications consume data from a variety of sources, including streaming sources like Apache Kafka, Kinesis or JMS, file based sources or databases. Processing results often need to be stored in external systems (sinks) for downstream consumers (pub-sub messaging, real-time visualization, Hive and other SQL databases etc.). Apex has the Malhar library with a wide range of connectors and other operators that are readily available to build applications. We will cover key characteristics like partitioning and processing guarantees, generic building blocks for new operators (write-ahead-log, incremental state saving, windowing etc.) and APIs for application specification.
Java 8 introduced several new features to the language including lambda expressions, default methods in interfaces, and static methods in interfaces. It also improved existing areas such as collections, date/time handling, concurrency, and I/O. Significant under-the-hood changes included replacing PermGen with Metaspace for class metadata and enabling AES encryption on newer CPUs.
ReactiveCocoa is a framework that uses functional reactive programming (FRP) to handle asynchronous data flows and events in a declarative way. It provides RACStream and RACSignal components to represent push-driven and pull-driven streams of data. RACSignal can be used to observe and chain together events like KVO observations. RACSequence represents pull-driven collections and adds higher-order functions. The document demonstrates using ReactiveCocoa and MVVM to build a reactive BMI calculator app, separating presentation logic from the view controller for easier testing and UI changes.
- Fluent Decorator
- In, Out, In, Out, Shake It All About
- The Lonely Override
- Monad
- Functional Reactive?
你可以在以下找到中文說明:
http://www.codedata.com.tw/social-coding/java8-patterns/
These are Java ways of functional style; pragmatic ways of understanding and introducing Lambda/Functional API.
你可以在以下找到中文說明:
http://www.codedata.com.tw/java/jdk8-functional-api/
A framework for nonlinear model predictive controlModelon
This document presents a new framework for nonlinear model predictive control (MPC) in JModelica.org. MPC is an optimal control strategy that solves an optimal control problem repeatedly online to determine the optimal inputs. The new framework aims to improve the computational efficiency of MPC in JModelica.org by reusing information between optimizations. It discretizes the optimal control problem once, rather than at each iteration. In a benchmark of controlling a combined cycle power plant, the new MPC framework achieved similar control performance as the existing open-loop framework but was significantly faster, taking around 70% less total time. The MPC framework also makes the JModelica.org modeling environment easier to use for MPC applications.
This document provides a brief overview of Java 8 features including functional interfaces, lambda expressions, stream API, and Optional class. It discusses how functional interfaces provide target types for lambda expressions and can have a single abstract method. Lambda expressions allow implementing functional interfaces concisely without anonymous classes. The stream API provides a powerful way to process collections in a declarative way using lambda expressions. The Optional class avoids null pointer exceptions and allows chaining of method calls on objects that may be null.
This document discusses the development of a new framework for modeling multi-component multi-phase mixtures in Modelica. The goals are to support both native Modelica media implementations and connections to external thermophysical property databases, address limitations of the existing Modelica.Media interface, and enable new applications involving multi-phase processes. A model-based interface structure is proposed to overcome restrictions of using pure functions. An example demonstrates the approach for simulating air separation processes using both a simple native Modelica air media and a connection to Refprop. Further testing and development is still needed to fully realize the new framework.
BigDataSpain 2016: Stream Processing Applications with Apache ApexThomas Weise
Stream processing applications built on Apache Apex run on Hadoop clusters and typically power analytics use cases where availability, flexible scaling, high throughput, low latency and correctness are essential. These applications consume data from a variety of sources, including streaming sources like Apache Kafka, Kinesis or JMS, file based sources or databases. Processing results often need to be stored in external systems (sinks) for downstream consumers (pub-sub messaging, real-time visualization, Hive and other SQL databases etc.). Apex has the Malhar library with a wide range of connectors and other operators that are readily available to build applications. We will cover key characteristics like partitioning and processing guarantees, generic building blocks for new operators (write-ahead-log, incremental state saving, windowing etc.) and APIs for application specification.
Java 8 introduced several new features to the language including lambda expressions, default methods in interfaces, and static methods in interfaces. It also improved existing areas such as collections, date/time handling, concurrency, and I/O. Significant under-the-hood changes included replacing PermGen with Metaspace for class metadata and enabling AES encryption on newer CPUs.
ReactiveCocoa is a framework that uses functional reactive programming (FRP) to handle asynchronous data flows and events in a declarative way. It provides RACStream and RACSignal components to represent push-driven and pull-driven streams of data. RACSignal can be used to observe and chain together events like KVO observations. RACSequence represents pull-driven collections and adds higher-order functions. The document demonstrates using ReactiveCocoa and MVVM to build a reactive BMI calculator app, separating presentation logic from the view controller for easier testing and UI changes.
- Fluent Decorator
- In, Out, In, Out, Shake It All About
- The Lonely Override
- Monad
- Functional Reactive?
你可以在以下找到中文說明:
http://www.codedata.com.tw/social-coding/java8-patterns/
Massif - the love child of Matlab Simulink and EclipseÁkos Horváth
Massif is a tool that integrates Matlab Simulink models with the Eclipse development environment. It provides import and export functionality for Simulink systems and libraries, representing them as EMF models in Eclipse. Massif has various import strategies and allows manipulating and navigating Simulink models directly as EMF resources. It also features an OSLC API to dynamically execute queries on Simulink models. The presentation provided an overview of Massif's architecture and capabilities and discussed experiences using it for avionics and automotive projects.
This document provides a whirlwind tour of tools for C programming in Unix, including gcc, make, gdb, emacs, and essential C concepts. It discusses how gcc is used to compile and link C programs. Makefiles are covered, including rules, targets, and variables. Debugging with gdb and emacs is demonstrated. Key C concepts like data types, pointers, strings, and static functions are summarized. The importance of initializing pointers is emphasized to avoid common errors.
Valgrind is a virtual machine that uses just-in-time compilation to translate programs into an intermediate representation before executing them, allowing tools to transform the representation to debug programs by detecting memory leaks and other errors without directly running the original code.
Operator overloading allows the same operator to behave differently depending on the operands. It allows performing different operations on the same operands, making code more readable and allowing easy access to objects to perform operations. An example demonstrates overloading the decrement operator (--) in a class to decrement an integer count and displaying the result. Function overloading uses a single function name to perform different tasks based on parameters. An example overloads the area function to calculate the area of a circle, square, and rectangle depending on parameters passed.
New in Spring Framework 5.0: Functional Web FrameworkVMware Tanzu
In Spring Framework 5.0, we introduced a new, functional web framework, next to the existing annotation-driven programming model. In this talk, we will discuss this new framework: how it is used, what its goals are, how it compares to the annotation model, and other related topics.
Presenter : Arjen Poutsma, Pivotal
Neutronium is an open-source PaaS framework for OpenStack that aims to provide an ecosystem for platform services. It allows various services like databases, load balancers, and web servers to be deeply integrated and easily combined. Neutronium uses components, templates, and models to declaratively specify and deploy multi-tier applications and services. It also provides APIs and tools to manage services and model resources.
Inline functions allow the compiler to replace function calls with the function's definition during compilation. This avoids overhead from function calls and improves execution speed. Inline functions can increase executable size due to code expansion. They are best for small functions where performance is critical, and care needs to be taken to avoid excessive code bloat.
Flink Forward SF 2017: Malo Deniélou - No shard left behind: Dynamic work re...Flink Forward
The Apache Beam programming model is designed to support several advanced data processing features such as autoscaling and dynamic work rebalancing. In this talk, we will first explain how dynamic work rebalancing not only provides a general and robust solution to the problem of stragglers in traditional data processing pipelines, but also how it allows autoscaling to be truly effective. We will then present how dynamic work rebalancing works as implemented in the Google Cloud Dataflow runner and which path other Apache Beam runners link Apache Flink can follow to benefit from it.
This presentation is Unary operator overloading(prefix).
Here ,I try to describe how to Unary operator overloaded and its types with example. may be you can happily read this.
This document provides information about a Java 8 Bootcamp training conducted by Mohamed Ben Hassine. It outlines the key topics that will be covered in the training including an introduction to lambda expressions, Java 8 Stream API, new date and time API, Nashorn JavaScript engine, and other Java 8 features. It also provides a brief history of Java releases and versions. The training will use an example project of building an employee management application to demonstrate and apply the Java 8 concepts over the course.
Explores and discusses benefits of functional programming in Java and how to program in a functional style. Watch Venkat Subramaniam's talk at https://youtu.be/Ee5t_EGjv0A if you would like to learn more.
Lambda expressions allow implementing functional interfaces using anonymous functions. Method references provide a shorthand syntax for referring to existing methods as lambda expressions. The Stream API allows functional-style operations on streams of values, including intermediate and terminal operations. The new Date/Time API provides a safer and more comprehensive replacement for the previous date/time classes in Java.
- Apache Apex is a platform and framework for building highly scalable and fault-tolerant distributed applications on Hadoop.
- It allows developers to build any custom logic as distributed applications and ensures fault tolerance, scalability and data flow. Applications can process streaming or batch data with high throughput and low latency.
- Apex applications are composed of operators that perform processing on streams of data tuples. Operators can run in a distributed fashion across a cluster and automatically recover from failures without reprocessing data from the beginning.
Java 9 is just around the corner. In this session, we'll describe the new modularization support (Jigsaw), new JDK tools, enhanced APIs and many performance improvements that were added to the new version.
This document introduces lambda expressions in Java 8. It provides background on why lambda expressions were added to Java, including to allow for more functional programming and parallel processing. It covers the syntax of lambda expressions, when they should and should not be used, functional interfaces, method and constructor references, referencing external variables, debugging lambda expressions, and new lambda methods added in Java 8. The document also advertises exercises for the reader to complete to practice using lambda expressions.
The document discusses new features in Java 8 including default methods in interfaces, lambda expressions, and streams. Default methods allow interfaces to include method implementations. Lambda expressions allow treating functionality as a method argument and code as data. Streams provide utilities for functional-style operations on collections of values and include intermediate and terminal operations.
Slides from my JAX London 2016 talk, discussing how the new features affect library design. Follows on from the Java SE 8 Best Practices talk - http://www.slideshare.net/scolebourne/java-se-8-best-practices-53975908
This document discusses operator overloading in C++. It defines operator overloading as allowing an operator to perform operations on user-defined types. It covers the concept, syntax, rules, advantages, disadvantages and provides an example of overloading the + and - operators for an integer class. Operations that can be overloaded include arithmetic, logical, relational, and pointer operators. The main advantage is improved readability and code reuse when working with user-defined types.
Massif - the love child of Matlab Simulink and EclipseÁkos Horváth
Massif is a tool that integrates Matlab Simulink models with the Eclipse development environment. It provides import and export functionality for Simulink systems and libraries, representing them as EMF models in Eclipse. Massif has various import strategies and allows manipulating and navigating Simulink models directly as EMF resources. It also features an OSLC API to dynamically execute queries on Simulink models. The presentation provided an overview of Massif's architecture and capabilities and discussed experiences using it for avionics and automotive projects.
This document provides a whirlwind tour of tools for C programming in Unix, including gcc, make, gdb, emacs, and essential C concepts. It discusses how gcc is used to compile and link C programs. Makefiles are covered, including rules, targets, and variables. Debugging with gdb and emacs is demonstrated. Key C concepts like data types, pointers, strings, and static functions are summarized. The importance of initializing pointers is emphasized to avoid common errors.
Valgrind is a virtual machine that uses just-in-time compilation to translate programs into an intermediate representation before executing them, allowing tools to transform the representation to debug programs by detecting memory leaks and other errors without directly running the original code.
Operator overloading allows the same operator to behave differently depending on the operands. It allows performing different operations on the same operands, making code more readable and allowing easy access to objects to perform operations. An example demonstrates overloading the decrement operator (--) in a class to decrement an integer count and displaying the result. Function overloading uses a single function name to perform different tasks based on parameters. An example overloads the area function to calculate the area of a circle, square, and rectangle depending on parameters passed.
New in Spring Framework 5.0: Functional Web FrameworkVMware Tanzu
In Spring Framework 5.0, we introduced a new, functional web framework, next to the existing annotation-driven programming model. In this talk, we will discuss this new framework: how it is used, what its goals are, how it compares to the annotation model, and other related topics.
Presenter : Arjen Poutsma, Pivotal
Neutronium is an open-source PaaS framework for OpenStack that aims to provide an ecosystem for platform services. It allows various services like databases, load balancers, and web servers to be deeply integrated and easily combined. Neutronium uses components, templates, and models to declaratively specify and deploy multi-tier applications and services. It also provides APIs and tools to manage services and model resources.
Inline functions allow the compiler to replace function calls with the function's definition during compilation. This avoids overhead from function calls and improves execution speed. Inline functions can increase executable size due to code expansion. They are best for small functions where performance is critical, and care needs to be taken to avoid excessive code bloat.
Flink Forward SF 2017: Malo Deniélou - No shard left behind: Dynamic work re...Flink Forward
The Apache Beam programming model is designed to support several advanced data processing features such as autoscaling and dynamic work rebalancing. In this talk, we will first explain how dynamic work rebalancing not only provides a general and robust solution to the problem of stragglers in traditional data processing pipelines, but also how it allows autoscaling to be truly effective. We will then present how dynamic work rebalancing works as implemented in the Google Cloud Dataflow runner and which path other Apache Beam runners link Apache Flink can follow to benefit from it.
This presentation is Unary operator overloading(prefix).
Here ,I try to describe how to Unary operator overloaded and its types with example. may be you can happily read this.
This document provides information about a Java 8 Bootcamp training conducted by Mohamed Ben Hassine. It outlines the key topics that will be covered in the training including an introduction to lambda expressions, Java 8 Stream API, new date and time API, Nashorn JavaScript engine, and other Java 8 features. It also provides a brief history of Java releases and versions. The training will use an example project of building an employee management application to demonstrate and apply the Java 8 concepts over the course.
Explores and discusses benefits of functional programming in Java and how to program in a functional style. Watch Venkat Subramaniam's talk at https://youtu.be/Ee5t_EGjv0A if you would like to learn more.
Lambda expressions allow implementing functional interfaces using anonymous functions. Method references provide a shorthand syntax for referring to existing methods as lambda expressions. The Stream API allows functional-style operations on streams of values, including intermediate and terminal operations. The new Date/Time API provides a safer and more comprehensive replacement for the previous date/time classes in Java.
- Apache Apex is a platform and framework for building highly scalable and fault-tolerant distributed applications on Hadoop.
- It allows developers to build any custom logic as distributed applications and ensures fault tolerance, scalability and data flow. Applications can process streaming or batch data with high throughput and low latency.
- Apex applications are composed of operators that perform processing on streams of data tuples. Operators can run in a distributed fashion across a cluster and automatically recover from failures without reprocessing data from the beginning.
Java 9 is just around the corner. In this session, we'll describe the new modularization support (Jigsaw), new JDK tools, enhanced APIs and many performance improvements that were added to the new version.
This document introduces lambda expressions in Java 8. It provides background on why lambda expressions were added to Java, including to allow for more functional programming and parallel processing. It covers the syntax of lambda expressions, when they should and should not be used, functional interfaces, method and constructor references, referencing external variables, debugging lambda expressions, and new lambda methods added in Java 8. The document also advertises exercises for the reader to complete to practice using lambda expressions.
The document discusses new features in Java 8 including default methods in interfaces, lambda expressions, and streams. Default methods allow interfaces to include method implementations. Lambda expressions allow treating functionality as a method argument and code as data. Streams provide utilities for functional-style operations on collections of values and include intermediate and terminal operations.
Slides from my JAX London 2016 talk, discussing how the new features affect library design. Follows on from the Java SE 8 Best Practices talk - http://www.slideshare.net/scolebourne/java-se-8-best-practices-53975908
This document discusses operator overloading in C++. It defines operator overloading as allowing an operator to perform operations on user-defined types. It covers the concept, syntax, rules, advantages, disadvantages and provides an example of overloading the + and - operators for an integer class. Operations that can be overloaded include arithmetic, logical, relational, and pointer operators. The main advantage is improved readability and code reuse when working with user-defined types.
This document provides an overview of building an Apache Apex application, including key concepts like DAGs, operators, and ports. It also includes an example "word count" application and demonstrates how to define the application and operators, and build Apache Apex from source code. The document outlines the sample application workflow and includes information on resources for learning more about Apache Apex.
Building Your First Apache Apex ApplicationApache Apex
This document provides an overview of building an Apache Apex application, including key concepts like DAGs, operators, and ports. It also includes an example "word count" application and demonstrates how to define the application and operators, and build Apache Apex from source code. The document outlines the sample application workflow and includes information on resources for learning more about Apache Apex.
The document provides an overview of the OPTIMICA Compiler Toolkit. It discusses the toolkit's capabilities for transient and steady-state time domain simulation and optimization. It also outlines Modelon's model-based development workflow using model libraries, authoring, compilers, solvers, and other technologies. Key features of the toolkit include Modelica and FMI-based computation, dynamic and steady-state simulation, optimization capabilities, and scripting APIs.
This document provides an overview of microservices and how to develop them using Spring. It discusses the challenges of distributed systems and how Spring Boot and Spring Cloud Netflix address areas like configuration, service registration, load balancing, fault tolerance, and monitoring. Examples are provided for building microservices with Spring Boot, integrating configuration with Spring Cloud Config, registering services with Eureka, load balancing with Ribbon and Feign, handling faults with Hystrix, and monitoring with Hystrix Dashboard. Reactive programming with RxJava is also introduced as an approach for concurrent API integration.
Java 8 includes new features such as lambda expressions for functional programming, streams API for bulk data operations, date and time API improvements, and miscellaneous enhancements. It also removes some deprecated features and improves performance.
- Angular is an open-source web application framework originally developed in 2009 that uses HTML as its template language. It is commonly used to create single-page applications.
- Angular uses MVC architecture and two-way data binding between models and views. It has built-in dependency injection which allows for testable and scalable code.
- Key Angular concepts include directives, filters, controllers and scopes which allow manipulating DOM elements and binding data. Modules are used to package code into reusable components.
Performance van Java 8 en verder - Jeroen BorgersNLJUG
We weten allemaal dat de grootste verbetering die Java 8 brengt de ondersteuning voor lambda-expressies is. Dit introduceert functioneel programmeren in Java. Door het toevoegen van de Stream API wordt deze verbetering nog groter: iteratie kan nu intern worden afgehandeld door een bibliotheek, je kunt daarmee nu het beginsel "Tell, don’t ask" toepassen op collecties. Je kunt gewoon vertellen dat er een ??functie uitgevoerd moet worden op je verzameling, of vertellen dat dat parallel, door meerdere cores moet gebeuren. Maar wat betekent dit voor de prestaties van onze Java-toepassingen? Kunnen we nu meteen volledig al onze CPU-cores benutten om betere responstijden te krijgen? Hoe werken filter / map / reduce en parallele streams precies intern? Hoe wordt het Fork-Join framework hierin gebruikt? Zijn lambda's sneller dan inner klassen? - Al deze vragen worden beantwoord in deze sessie. Daarnaast introduceert Java 8 meer performance verbeteringen: tiered compilatie, PermGen verwijdering, java.time, Accumulators, Adders en Map verbeteringen. Ten slotte zullen we ook een kijkje nemen in de keuken van de geplande performance verbeteringen voor Java 9: benutting van GPU's, Value Types en arrays 2.0.
Function Mesh for Apache Pulsar, the Way for Simple Streaming SolutionsStreamNative
Pulsar Function is a succinct computing abstraction Apache Pulsar provides to express simple ETL and streaming tasks. The simplicity comes in two folds: Simple Interface and Simple Deployment. As it has been adopted, we realized that the ability to run natively on cloud and integrate multiple functions into one integrity are key to user success. We developed this new feature -- Function Mesh -- to support these new requirements.
This talk aims to provide a thorough walkthrough of this new Function Mesh Feature, including its design, implementation, use cases, and examples, to help people seeking simple streaming solutions understand this newly created powerful tool in Apache Pulsar.
Java Webinar #12: "Java Versions and Features: Since JDK 8 to 16"GlobalLogic Ukraine
This webinar by Oleksandr Bodnar (Lead Software Engineer, GlobalLogic) was delivered at Java Community Webinar #12 on July 14, 2021.
Webinar abstracts:
- Java History: OpenJDK and Oracle JDK
- Java EE (Jakarta EE) vs SE vs ME
- JEP Java SE 8-16
- Future editions of Java
More details and presentation: https://www.globallogic.com/ua/about/events/java-community-webinar-12/
Interface changes: ha habido cambios bastante significativos en lo que a interfaces se refiere
Lambda expressions: es quizá la mayor novedad en esta versión junto con los cambios en las interfaces, no es nada nuevo ya que otros lenguajes como Scala o Groovy lo incorporan
Streams: Son secuencias de elementos sobre los cuales se pueden aplicar operaciones de forma secuencial o paralela
Nashorn: Es el nuevo motor JS que sustituye a Rihno
Java FX: Es el cliente UI de java y ha mejorado mucho a nivel visual y a nivel de soporte 3D
De esta manera nos podemos ahorrar el tener una clase con métodos estáticos que interactúen con las interfaces, se pueden tener esos métodos definidos directamente en las interfaces.
Los métodos por defecto son como su propio nombre indican la implementación por defecto que tendrán esos métodos si la clase que implementa la interfaz no lo implementa.
Para que una interfaz sea funcional ha de cumplir solo una norma, declarar un único método abstracto.
La anotación no es obligatoria, pero se recomienda encarecidamente para que se muestren ciertos errores de compilación.
Las lambda expressions junto con las interfaces funcionales son quizá la mayor novedad desde la introducción de genéricos en java 5.
Es un concepto que ya esta en otros lenguajes como Scala o Groovy, así que no es que hayan inventado nada nuevo.
Sirven principalmente para instanciar las interfaces funcionales,
- Las lambda expressions pueden tener varias formas, por ejemplo:
Comma-separated list of inputs with specified types on the left, a block with a return on the right
Lo mismo de arriba pero con inferencia de tipo el codigo mas simplificado
Single parameter with inferred type on the left, a return value on the right
No inputs on left (official name: "burger arrow"), return value on the right
Single parameter with inferred type on the left, a block with no return (void return) on the right
Tmabién pueden hacer referencia a métodos, ya sean estáticos, no estáticos, de una variable capturada de fuera de la expression o incluso referencias a constructores.
Todo ha de coincid9ir con la interfaz funcional, tanto lo sargumentos de entrada, como la salida, como las excepciones que se lancen, una lambda no puede lanzar excepciones que no han sido declaradas en la interfaz funcional.
Solo se pueden usar variables efectivamente finales en el cuerpo de las lambda. Que una variable sea efectivamente final quiere decir que se ha declarado con el modificador final o que no se ha modificado despues de su asignación.
No se puede romper un bucle dentro de una lambda expression, se seguira ejecutando el codigo para el resto de elementos.
- Como ya he dicho en la introduccion, los streams son Son secuencias de elementos sobre los cuales se pueden aplicar operaciones de forma secuencial o paralela.
Solo pueden ser usados una vez, no se pueden reutilizar, si se obtiene otra vez un stream del mismo objeto, será uno totalmente nuevo.
Típicamente los streams se obtienen de las colecciones.
steps:
Obtain a stream from some source.
Perform one or more intermediate operations.
Perform one terminal operation.
Uno puede hacer muchas operaciones intermedias con un stream siempre y cuando luego haga una operacion terminal.
Es muy habitual ver lambda expressions en dichas operaciones.
En el primer ejemplo se aplican operaciones para transformar el stream a sus equivalentes primitivos, que tienen sus métodos especificos.
En el segundo se aplican ciertas operaciones intermedias y al final se usa el método collect a la que se le puede pasar la interfaz a la que quieres transformar el stream resultante.
Nashron es el nuevo motor JS que viene incluido con java 8, es el sucesor de Rhino
Con Nashorn es posible ejecutar codigo Java desde JS y código JS en Java.
Avatar.js es un proyecto de Oracle cuyo objetivo es adaptar toda la funcionalidad existente en Node.js, dando compatibilidad incluso a muchos de los módulos de Node.
Por que?
Os preguntaréis por que ustilizar Nashron si ya está node que funciona muy bien, según la gente de Oracle hay varios motivos, yo creo que la única situación que si que seria muy util es cuando hay que soportar código antiguo en Java.
Es el conjunto de paquetes y componentes para crear aplicaciones java de escritorio. Java FX es el sustituto de Swing, aunque Swing aún se puede usar en el futuro será completamente sustituido.
Las aplicaciones de swing seguro que recordais que son bastante feas, pues bien con este nuevo tema, visualmente mejoran mucho
- Con la incursion de los métodos estaticos en las interfaces y de los default methods se han introducido muchos métodos en APIs ya existentes
- Date: toda la API de fechas ha sido rediseñada desde cero (JodaTime style)
Joda time es la librería estandar. que casi todo desarrollador Java utiliza cuando el API de Java se queda corta en cuanto a funcionalidad.
Aunque es muy similar a JodaTime, Oracle optó por rediseñarla desde cero porque Oracle consideraba que tenía pequeños fallos de diseño, que prácticamente ningún desarrollador notaria, pero que los tenía.
Son un conjunto de interfaces muy útiles y que son ampliamente usadas en los métodos nuevos que aceptan Lambda expressions.
Cada una de las interfaces anteriores se pordian instanciar con lambdas que cumplan esas condiciones.
Como ahora las interfaces pueden definir métodos por defecto se han añadido muchos métodos a las interfaces de las APIs de collection, como las que podeis ver. En Varias de ellas veréis interfaces funcionales como argumentos, esto es un indicativo de la importancia de ellas junto de las lambdas para poder usarlas.
Concurrency additions son para hacer más eficiente la concurrencia.
IO/NIO: la mayoria de los nuevos métodos es para interactuar con streams.
Ha habido muchisimos métodos y APIS nuevas, especialmente en esos dos paquetes, pero también en muchos otros paquetes. Como ejemplo se puede ver que la ordenación ha mejorado muchisimo y ahora es mas facil realizar ordenaciones complejas.
Se supone que se ha trabajado mucho en el rendimiento de la JVM en esta versión. O al menos eso dijeron en el screen cast del mes pasado.
Supongo que a muchos de vosotros os ha pasado el típico error de permgen space, pues bien esto no debería pasar más:
Para empezar porque se elimina el Permgen space, así que si da algún error ya no será el mismo.
Se sustituye por MetaSpace, que no tiene limitado su tamaño por defecto, es dinámico y se puede limitar como argumento al arrancar la JVM
Se han añadido nuevos métodos y clases en el paquete java.util.concurrent para aumentar el rendimiento y la escalabilidad de las aplicaciones concurrentes.
La Tiered compilation es una característica que se introdujo en java 7 pero se ha habilitado por defecto. La máquina virtual se puede arrancar en modo cliente o modo servidor y en función de esto se tuneará de una manera u otra, pues bien antes del tiered compilation el arranque de la server VM era mucho mayor que el del client mode, ahora con esta caracteristica ambos tiempos son similares.