Digital Edition

SYS-CON.TV
Revisiting Java SE 7 Features | @CloudExpo #Java #Cloud #OpenSource
A tutorial series on Java as we all eagerly await the official release of Java SE 9

Preparing for an interview? Want to just revisit Java SE 7 features? Trying to recollect or revise a Java SE programming construct? Let me take you back in time to what was introduced first in Java SE 7? Join me for this tutorial series on Java as we all eagerly await the official release of Java SE 9.

Java SE 7 Release Date: 28-07-2011

Java SE 7 Code Name: Dolphin

Java SE 7 Highlights

  • Strings in switch statements.
  • Automatic resource management in try statements.
  • Improved type inference for generic instance creation, AKA the diamond operator <>.
  • Simplified varargs method declaration.
  • Binary integer literals.
  • Allowing underscores in numeric literals.
  • Catching multiple exception types and rethrowing exceptions with improved type checking.

I have provided some of the most important core language enhancements for JDK 7.0, along with code samples. The examples provided below can be directly pasted into your IDE, and you may name the class as provided.

Strings in Switch Statements
You may use Strings in your switch statements, which is a powerful tool. The alternative would have been to use a series of if statements with an .equals() comparison. You may directly execute the code below in Eclipse to understand it better.

public class jdk7_StringSwitch {
static String day = "SAT";
public static void main(String[] args) {
switch(day) {
case "MON": { System.out.println("Monday"); break; }
case "TUE": { System.out.println("Tuesday"); break; }
case "SUN": { System.out.println("Sunday"); break; }
case "SAT": { System.out.println("Saturday"); break; }
}
}
}

Multiple Exception Handling
Before JDK7, you would have to catch multiple exceptions in a block - with a catch block for each of the thrown checked exceptions. But sometimes you may want to take actions for many exceptions that are similar or the same. Hence, the utility of this feature. You may directly execute the code below in Eclipse to understand it better.

public class jdk7_ExceptionHandling {
public static void main(String[] args) {
try {
Integer value = Integer.parseInt("ABC");
File file = new File("exception.txt");
FileReader fileReader = new FileReader(file);
} catch(NumberFormatException | FileNotFoundException foe) {
System.out.println("Multiple Exception Types");
}
}
}

Try With Resources
You may use/create a resource withing the try block, from JDK7, and use it within the following block. This includes all objects/resources that implement java.io.Closeable. Automatically, on encountering the exception or if there is no exception, the close() method is guaranteed to be called by the runtime.

public class jdk7_TryWithResources {
public static void main(String[] args) throws IOException {
try(BufferedReader br = new BufferedReader(new FileReader("file.txt"))) {
br.readLine();
} finally {
System.out.println("All Resources Closed.");
} }
}

Make sure that you have a file.txt in your classpath.

About 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.



ADS BY GOOGLE
Subscribe to the World's Most Powerful Newsletters

ADS BY GOOGLE

Lori MacVittie is a subject matter expert on emerging technology responsible for outbound evangelism...
Technological progress can be expressed as layers of abstraction - higher layers are built on top of...
"Calligo is a cloud service provider with data privacy at the heart of what we do. We are a typical ...
Having been in the web hosting industry since 2002, dhosting has gained a great deal of experience w...
NanoVMs is the only production ready unikernel infrastructure solution on the market today. Unikerne...
CloudEXPO | DevOpsSUMMIT | DXWorldEXPO Silicon Valley 2019 will cover all of these tools, with the m...
SUSE is a German-based, multinational, open-source software company that develops and sells Linux pr...
Your job is mostly boring. Many of the IT operations tasks you perform on a day-to-day basis are rep...
When building large, cloud-based applications that operate at a high scale, it’s important to mainta...
In his general session at 19th Cloud Expo, Manish Dixit, VP of Product and Engineering at Dice, disc...
Big Switch's mission is to disrupt the status quo of networking with order of magnitude improvements...
Dynatrace is an application performance management software company with products for the informatio...
In his session at 21st Cloud Expo, Michael Burley, a Senior Business Development Executive in IT Ser...
All in Mobile is a mobile app agency that helps enterprise companies and next generation startups bu...
Yottabyte is a software-defined data center (SDDC) company headquartered in Bloomfield Township, Oak...
Serveless Architectures brings the ability to independently scale, deploy and heal based on workload...
Whenever a new technology hits the high points of hype, everyone starts talking about it like it wil...
Every organization is facing their own Digital Transformation as they attempt to stay ahead of the c...
Bill Schmarzo, Tech Chair of "Big Data | Analytics" of upcoming CloudEXPO | DXWorldEXPO New York (No...
Chris Matthieu is the President & CEO of Computes, inc. He brings 30 years of experience in developm...