SYS-CON MEDIA Authors: Jason Bloomberg, Elizabeth White, Zakia Bouachraoui, Andy Thurai, Liz McMillan

Article

Revisitng Java SE 5 Features! @CloudExpo #Java #Cloud #OpenSource5

A tutorial series on Java as we all eagerly await the official release of Java SE 9

I have provided some of the most important core language enhancements for JDK 5.0, along with code samples. The examples provided below can be directly pasted into your IDE and you may name the class as provided.

Type Safe Enumerations
Enumerations are provided as an easier way to maintain similar values (constants) that can be assigned to a type. The keyword used is enum. You may additionally define constructors. The method ordinal() will return the index of the enum constant and the method name() will return the name of the enum constants. You may also use valueOf() to return the value of a string as an enum constant. You may directly execute the code below in Eclipse to understand better.
 public class jdk5_Enum {  
      public static enum Java {JDK5, JDK6, JDK7, JDK8};  
      public static enum JavaVer {   
           JDK5(5), JDK6(6), JDK7(7), JDK8(8);  
           int x;  
           JavaVer(int x) {  
                this.x = x;  
           }  
      }  
     
      public static void main(String[] args) {  
           Java java = Java.JDK6;  
           System.out.println(Java.JDK5);  
           System.out.println(java);  
           System.out.println(java.ordinal() + ":" + java.name());  
           JavaVer javaVer = JavaVer.JDK7;  
           System.out.println(javaVer.x);  
           System.out.println(javaVer.ordinal() + ":" + javaVer.name());  
           String myJava = "JDK8";  
           System.out.println(Java.valueOf(myJava));  
           JavaVer javaSwitchVer=JavaVer.JDK6;  
           switch(javaSwitchVer) {  
                case JDK5: {System.out.println("5.0"); break;}  
                case JDK6: {System.out.println("6.0"); break;}  
                case JDK7: {System.out.println("7.0"); break;}  
                case JDK8: {System.out.println("8.0"); break;}  
           }  
      }  
 }  


Variable Arguments
Varargs should be provided as the last parameter of any method and can be used to pass zero or more arguments to the method. You may directly execute the code below in Eclipse to understand better.
 public class jdk5_Varargs {  
      public void getData(String...values) {  
           for(String string:values) {  
                System.out.println(string);  
           }  
      }  
     
      public static void main(String[] args) {  
           jdk5_Varargs varargs = new jdk5_Varargs();  
           varargs.getData("Apple","Banana","Cucumber","Radish");       
           String[] vargs = new String[] {"Radia","Cloud","Hewlett","Packard"};  
           varargs.getData(vargs);  
      }  
 }  


Generics
Generics is used to maintain compile-time type safety on code. It follows type erasure and allows to maintain a control over the types that can be maintained in collections. You may also use generics to define method or class 'templates'. You may directly execute the code below in Eclipse to understand better. For more on generics, refer to my article in CodeGuru.
 public class jdk5_Generics {  
      List<String> genericList = new ArrayList<String>();  
   
      public static void main(String[] args) {            
           jdk5_Generics jGenerics = new jdk5_Generics();  
           // generic for type safety  
           List<String> jGenericsList = jGenerics.genericList;  
           jGenericsList.add("Sumith");  
           jGenericsList.add("Kumar");  
           jGenericsList.add("Puri");  
           for(String str:jGenericsList) {  
                System.out.println(str);  
           }  
           // generic variables - class and method generic templates  
           List<? extends Vehicle> jGenericObjList = new ArrayList();  
           Vehicle car = new Car();  
           RentVehicle<Vehicle> rentVehicle = new RentCar<Car>();  
           rentVehicle.rentOut(car);  
      }  
 }  
 class Vehicle {  
      Integer regn;  
      String type;  
      public Integer getRegn() {  
           return regn;  
      }  
      public void setRegn(Integer regn) {  
           this.regn = regn;  
      }  
      public String getType() {  
           return type;  
      }  
      public void setType(String type) {  
           this.type = type;  
      }            
 }  
 class Car extends Vehicle {  
 }  
 interface RentVehicle <T extends Vehicle> {  
      public void rentOut(T vehicle);  
 }  
 class RentCar<Car> implements RentVehicle{  
      public void rentOut(Vehicle vehicle) {            
           System.out.println("Rent Vehicle => Rent Car");  
      }  
 }  


Autoboxing/Unboxing
Autoboxing or Unboxing will allow to convert from primitive types to wrapper types and vice versa. You may directly execute the code below in Eclipse to understand better.
 public class jdk5_Autoboxing {  
      Integer integer = new Integer(50);  
      public void setValue(int integer) {  
      }  
      public Integer getValue() {  
           return integer;  
      }  
      public Float getFloat() {  
           return 6.0f;  
      }  
      /**  
       * @param args  
       */  
      public static void main(String[] args) {            
           jdk5_Autoboxing autoboxing = new jdk5_Autoboxing(); // autounboxing  
           autoboxing.setValue(new Integer(5));  
           int x = autoboxing.getValue();  
           // this is not valid => autounboxing - upcasting - autoboxing  
           // Double y = autoboxing.getFloat();  
      }  
 }  


Enhanced For Loop
Enhanced For Loop allows an easier way to loop through objects of a common super-type. You may directly execute the code below in Eclipse to understand better.
 public class jdk5_EnhancedFor {  
      public static void main(String[] args) {  
           jdk5_EnhancedFor ef = new jdk5_EnhancedFor();  
           List<Animal> animals = new ArrayList();  
           Animal animal = new Animal();  
           animals.add(animal);  
           animal = new Dog();  
           animals.add(animal);  
           animal = new Cat();  
           animals.add(animal);  
           animal = new Dog();  
           animals.add(animal);  
           animal = new Cat();  
           animals.add(animal);  
           animal = new Dog();  
           animals.add(animal);  
           animal = new Animal();  
           animals.add(animal);  
           animal = new Animal();  
           animals.add(animal);  
           for(Animal anim: animals) {  
                anim.print();  
           }  
      }  
 }  
 class Animal {  
      public void print() {  
           System.out.println("Animal");  
      }  
 }  
 class Dog extends Animal {  
      public void print() {  
           System.out.println("Dog");  
      }  
 }  
 class Cat extends Animal {  
      public void print() {  
           System.out.println("Cat");  
      }  
 }  


Static Imports
Static Imports allows you to import static methods and fields from other classes or interfaces, most useful when you to easily refer to static members from other classes without the reference of their class. You may directly execute the code below in Eclipse to understand better. Note that it is a compile-time error to import a type from unnamed or default package.
 import static jdk5.features.jdk5_StaticImport_Source.product;  
 public class jdk5_StaticImport {  
      public static void main(String[] args) {  
           System.out.println(product);  
      }  
 }  
The source for importing the above is the following class which is located under the package 'jdk5.features'

 package jdk5.features;
 public class jdk5_StaticImport_Source {  
      public static final String product = "radia-cloud";  
      public static final String version = "09.20.0000";  
      public static void setup() {  
           System.out.println("Setting up the Radia Server....");  
      }  
      public static void init() {  
           System.out.println("Initializing the Radia Server....");  
      }  
 }  


Annotations
Annotations are way of syntactic meta-data to inform and use that it signifies a specific type of functionality that can be processed using reflection. It can also be used to suppress warnings and inform of errors. The source file below is located under the package 'jdk5.features'
 package jdk5.features;  
 import java.lang.annotation.ElementType;  
 import java.lang.annotation.Retention;  
 import java.lang.annotation.RetentionPolicy;  
 import java.lang.annotation.Target;  
 @Retention(RetentionPolicy.RUNTIME)  
 @Target({ElementType.FIELD,ElementType.METHOD})  
 public @interface jdk5_Annotation_Source {  
 }  

The RetentionPolicy as mentioned can be either of Runtime (Retained by VM), Source (Discarded by Compiler) or Class (Not be Retained by VM). The source below is located under the package 'jdk5.features'
 package jdk5.features;  
 public class jdk5_Annotation_Usage {  
      @jdk5_Annotation_Source  
      public String myMessage;  
      public void annotated() {  
           System.out.println(myMessage);  
      }  
 }  

Now, You may directly execute the code below in Eclipse to understand Annotations better. (Default Package)
 import java.lang.reflect.Field;  
 import jdk5.features.jdk5_Annotation_Source;  
 import jdk5.features.jdk5_Annotation_Usage;  
 
 public class jdk5_AnnotationProcessor {  
      public static void main(String[] args) throws Exception {  
           jdk5_Annotation_Usage message = new jdk5_Annotation_Usage();  
           Field[] method = message.getClass().getDeclaredFields();  
           for(Field methd: method) {  
                jdk5_Annotation_Source annos = methd.getAnnotation(jdk5_Annotation_Source.class);                 
                if(annos != null) {  
                     methd.set(message,"Messenger of God!");  
                     // using reflection & annotations we set the value - check if set                  
                     message.annotated();   
                }  
           }  
      }  
 }  



Happy Coding with JDK 5!

More Stories By Sumith Kumar Puri

Sumith Kumar Puri, an author (Java/JEE) at Packt Publishing, has close to 14 years of experience in entrepreneurship, conceptualization, architecture, design and development of software products and solutions. He also holds multiple certifications in Core Java, JEE, C, C++, Algorithms and Data Structures. He is an open source contributor and likes competitive programming and hackathons. He has 11 publications to his name in international and national conferences, journals and magazines. He is an active member of the IEEE/Computer Society, ACM and CSI.

He holds a Bachelor of Engineering [Information Science and Engineering] from Sri Revana Siddeshwara Institute of Technology, Bangalore, India. He has also completed the Executive Programme [Data Mining and Analytics] from the Indian Institute of Technology, Roorkee, India and the Executive Certificate Programme [Entrepreneurship] from the Indian Institute of Management, Kashipur, India. His current interests are in data mining, machine learning, Big Data and artificial intelligence. He is based out of Bangalore, India.

Latest Stories
"We were founded in 2003 and the way we were founded was about good backup and good disaster recovery for our clients, and for the last 20 years we've been pretty consistent with that," noted Marc Malafronte, Territory Manager at StorageCraft, in this SYS-CON.tv interview at 20th Cloud Expo, held June 6-8, 2017, at the Javits Center in New York City, NY.
Historically, some banking activities such as trading have been relying heavily on analytics and cutting edge algorithmic tools. The coming of age of powerful data analytics solutions combined with the development of intelligent algorithms have created new opportunities for financial institutions. In his session at 20th Cloud Expo, Sebastien Meunier, Head of Digital for North America at Chappuis Halder & Co., discussed how these tools can be leveraged to develop a lasting competitive advantage ...
In his keynote at 18th Cloud Expo, Andrew Keys, Co-Founder of ConsenSys Enterprise, provided an overview of the evolution of the Internet and the Database and the future of their combination – the Blockchain. Andrew Keys is Co-Founder of ConsenSys Enterprise. He comes to ConsenSys Enterprise with capital markets, technology and entrepreneurial experience. Previously, he worked for UBS investment bank in equities analysis. Later, he was responsible for the creation and distribution of life settl...
DevOps is often described as a combination of technology and culture. Without both, DevOps isn't complete. However, applying the culture to outdated technology is a recipe for disaster; as response times grow and connections between teams are delayed by technology, the culture will die. A Nutanix Enterprise Cloud has many benefits that provide the needed base for a true DevOps paradigm. In their Day 3 Keynote at 20th Cloud Expo, Chris Brown, a Solutions Marketing Manager at Nutanix, and Mark Lav...
@CloudEXPO and @ExpoDX, two of the most influential technology events in the world, have hosted hundreds of sponsors and exhibitors since our launch 10 years ago. @CloudEXPO and @ExpoDX New York and Silicon Valley provide a full year of face-to-face marketing opportunities for your company. Each sponsorship and exhibit package comes with pre and post-show marketing programs. By sponsoring and exhibiting in New York and Silicon Valley, you reach a full complement of decision makers and buyers in ...
According to the IDC InfoBrief, Sponsored by Nutanix, “Surviving and Thriving in a Multi-cloud World,” multicloud deployments are now the norm for enterprise organizations – less than 30% of customers report using single cloud environments. Most customers leverage different cloud platforms across multiple service providers. The interoperability of data and applications between these varied cloud environments is growing in importance and yet access to hybrid cloud capabilities where a single appl...
"At the keynote this morning we spoke about the value proposition of Nutanix, of having a DevOps culture and a mindset, and the business outcomes of achieving agility and scale, which everybody here is trying to accomplish," noted Mark Lavi, DevOps Solution Architect at Nutanix, in this SYS-CON.tv interview at @DevOpsSummit at 20th Cloud Expo, held June 6-8, 2017, at the Javits Center in New York City, NY.
In today's always-on world, customer expectations have changed. Competitive differentiation is delivered through rapid software innovations, the ability to respond to issues quickly and by releasing high-quality code with minimal interruptions. DevOps isn't some far off goal; it's methodologies and practices are a response to this demand. The demand to go faster. The demand for more uptime. The demand to innovate. In this keynote, we will cover the Nutanix Developer Stack. Built from the foundat...
"NetApp's vision is how we help organizations manage data - delivering the right data in the right place, in the right time, to the people who need it, and doing it agnostic to what the platform is," explained Josh Atwell, Developer Advocate for NetApp, in this SYS-CON.tv interview at 20th Cloud Expo, held June 6-8, 2017, at the Javits Center in New York City, NY.
Sold by Nutanix, Nutanix Mine with Veeam can be deployed in minutes and simplifies the full lifecycle of data backup operations, including on-going management, scaling and troubleshooting. The offering combines highly-efficient storage working in concert with Veeam Backup and Replication, helping customers achieve comprehensive data protection for all their workloads — virtual, physical and private cloud —to meet increasing business demands for uptime and productivity.
"Cloud computing is certainly changing how people consume storage, how they use it, and what they use it for. It's also making people rethink how they architect their environment," stated Brad Winett, Senior Technologist for DDN Storage, in this SYS-CON.tv interview at 20th Cloud Expo, held June 6-8, 2017, at the Javits Center in New York City, NY.
While the focus and objectives of IoT initiatives are many and diverse, they all share a few common attributes, and one of those is the network. Commonly, that network includes the Internet, over which there isn't any real control for performance and availability. Or is there? The current state of the art for Big Data analytics, as applied to network telemetry, offers new opportunities for improving and assuring operational integrity. In his session at @ThingsExpo, Jim Frey, Vice President of S...
A look across the tech landscape at the disruptive technologies that are increasing in prominence and speculate as to which will be most impactful for communications – namely, AI and Cloud Computing. In his session at 20th Cloud Expo, Curtis Peterson, VP of Operations at RingCentral, highlighted the current challenges of these transformative technologies and shared strategies for preparing your organization for these changes. This “view from the top” outlined the latest trends and developments i...
The Internet of Things is clearly many things: data collection and analytics, wearables, Smart Grids and Smart Cities, the Industrial Internet, and more. Cool platforms like Arduino, Raspberry Pi, Intel's Galileo and Edison, and a diverse world of sensors are making the IoT a great toy box for developers in all these areas. In this Power Panel at @ThingsExpo, moderated by Conference Chair Roger Strukhoff, panelists discussed what things are the most important, which will have the most profound e...
In his keynote at 19th Cloud Expo, Sheng Liang, co-founder and CEO of Rancher Labs, discussed the technological advances and new business opportunities created by the rapid adoption of containers. With the success of Amazon Web Services (AWS) and various open source technologies used to build private clouds, cloud computing has become an essential component of IT strategy. However, users continue to face challenges in implementing clouds, as older technologies evolve and newer ones like Docker c...