Upgrade your Java skills with these top code examples and download Java 11 for 64-bit systems

Table of content

  1. Introduction
  2. Getting Started with Java 11
  3. Code Example 1: Lambda Expressions
  4. Code Example 2: Var Type Inference
  5. Code Example 3: Optional Class
  6. Code Example 4: New HTTP Client API
  7. Code Example 5: Multi-Release JAR Files
  8. Code Example 6: Interface Private Methods
  9. Conclusion and Download Java 11 for 64-bit Systems

Introduction

Welcome to the world of Java programming! Whether you're a beginner or an experienced programmer, these top code examples and tips will help you upgrade your Java skills and take your coding to the next level. Additionally, we strongly recommend downloading Java 11 for 64-bit systems to ensure you have the latest and greatest tools at your fingertips.

Java is a powerful and versatile language used for building everything from mobile apps to big data systems. However, learning a new programming language can be intimidating, so we've put together some tips to help you get started.

First and foremost, we recommend starting with the official Java tutorial, which covers everything from basic syntax to advanced topics like multithreading and network programming. From there, it's crucial to practice your coding skills by working on your own projects and experimenting with different coding techniques.

While there are many resources available for learning Java, we caution against buying too many books or using complex IDEs before you've mastered the basics. Instead, we recommend subscribing to websites, blogs, and social media channels focused on Java development to stay up-to-date on the latest trends and strategies.

Overall, learning Java requires a combination of dedication, practice, and a willingness to experiment and learn through trial and error. By following these tips and staying engaged with the Java community, you'll be well on your way to becoming a skilled Java programmer!

Getting Started with Java 11

Java 11 is the latest major release of the Java programming language, and it brings many new features and improvements over previous versions. If you're just starting with Java or looking to upgrade your skills to the latest version, here are some tips to help you get started:

1. Download Java 11 for 64-bit systems

The first step is to download and install Java 11 on your computer. Make sure to select the version that matches your system architecture, such as 64-bit if you're running a 64-bit operating system. You can download Java 11 from the official website or using a package manager if you're using Linux.

2. Follow the official Java tutorial

The official Java tutorial is a comprehensive guide to learning Java from scratch, and it's a great place to start. It covers everything from basic syntax and programming concepts to more advanced topics such as concurrency and networking. Follow the tutorial step-by-step, and try out the code examples as you go along.

3. Join Java communities

Being part of the Java community is a great way to learn, ask questions, and get help from more experienced developers. Join popular Java forums such as Stack Overflow, Java Ranch, or Reddit's r/java community. Follow Java blogs and Twitter accounts to stay up-to-date with the latest news and trends in the Java world.

4. Build your own Java projects

Don't just read about Java – start building your own projects. Create simple Java programs, such as a calculator or a game, and gradually increase the complexity as you gain more experience. Experiment with different Java libraries and frameworks, and try out new features in Java 11. The more you practice, the more confident and proficient you'll become.

5. Don't get overwhelmed

Java is a vast and powerful language, but it can be overwhelming for beginners. Don't try to learn everything at once – focus on the basics first, and gradually move on to more complex topics. Avoid buying expensive books or using complex Integrated Development Environments (IDEs) until you've mastered the fundamentals. Build your skills and knowledge at a comfortable pace, and don't be afraid to make mistakes and learn through trial and error.

By following these tips, you'll be on your way to upgrading your Java skills and becoming a proficient Java developer. Good luck!

Code Example 1: Lambda Expressions

Lambda expressions are a powerful feature introduced in Java 8 that allows you to write concise and functional code. They are particularly useful for working with collections and streams in Java.

Here is an example of how you can use a lambda expression to sort a list of strings in alphabetical order:

List<String> names = Arrays.asList("Alice", "Bob", "Charlie", "Dave");

Collections.sort(names, (s1, s2) -> s1.compareTo(s2));

System.out.println(names); // prints [Alice, Bob, Charlie, Dave]

In this example, we create a list of names and then use a lambda expression as the second argument to the Collections.sort() method. The lambda expression compares two strings using the compareTo() method and returns the result.

Lambda expressions can be used in many other contexts in Java, such as filtering and mapping data in streams. They can also be combined with method references to create even more concise code.

To learn more about lambda expressions and how to use them effectively, I recommend checking out the official Java tutorial on lambdas and streams. Practice writing your own lambda expressions and try to refactor existing code using lambdas to gain proficiency in this important aspect of Java programming.

Code Example 2: Var Type Inference


One of the most exciting additions to Java 11 is the var type inference feature. This allows you to declare a variable without specifying its data type, and the compiler will automatically infer it based on its initial value. This can greatly simplify your code and make it more readable.

Here's an example:

var name = "John";

In this code, we haven't explicitly stated that "name" is a string, but since we're assigning it a string value ("John"), the compiler knows that it's a string.

However, there are some guidelines to follow when using this feature. You shouldn't use it when declaring fields or method signatures, and you should still strive for meaningful variable names.

Here's another example:

var numbers = List.of(1, 2, 3);

In this code, we're using the List.of() method to create a list of integers. Since we haven't specified the data type for the "numbers" variable, the compiler will automatically infer that it's a List.

The var type inference feature is a great addition to Java, but it should be used judiciously. It can simplify your code and make it more readable, but don't go overboard with it. Be sure to use meaningful variable names and follow established coding conventions.

Code Example 3: Optional Class

One of the most common issues in programming is dealing with null values. In Java, the Optional class can help us handle situations where a value might be null. The Optional class is a container object that may or may not contain a non-null value.

Let's take a look at a simple example. Consider a function that returns a Person object. In some cases, the Person object might be null. Without the Optional class, we would have to check for null values every time we call this function. However, with the Optional class, we can easily handle the null case by returning an Optional object.

public Optional<Person> getPerson() {
  // return a Person object if it exists, otherwise return an empty Optional object
  return Optional.ofNullable(person);
}

In the code above, we use the ofNullable method to create an Optional object that may or may not contain a Person object. If the Person object is null, then we return an empty Optional object.

To retrieve the Person object from the Optional container, we have several methods available. One common method is orElse, which returns the value of the Optional container if it's not empty or a default value if it is empty. This can be useful for setting default values or handling null cases.

Optional<Person> personOptional = getPerson();
Person person = personOptional.orElse(new Person("John", "Doe"));

In the code above, we use the orElse method to retrieve the Person object from the Optional container. If the Optional container is empty, then we return a default Person object with the name "John Doe".

Overall, the Optional class is a powerful tool that can help us handle null values effectively in our code. By using the Optional class, we can write more concise, readable, and maintainable code.

Code Example 4: New HTTP Client API

Java 11 introduces a new HTTP Client API that supports both synchronous and asynchronous communication. The new API is designed to be lightweight and easy to use, making it ideal for developing modern web applications. Here's a code example that demonstrates how to use the new API to send a GET request to a website:

import java.io.IOException;
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;

public class HttpClientExample {
  public static void main(String[] args) throws IOException, InterruptedException {
    HttpClient httpClient = HttpClient.newHttpClient();
    HttpRequest httpRequest = HttpRequest.newBuilder()
            .uri(URI.create("https://example.com"))
            .build();
    HttpResponse<String> httpResponse = httpClient.send(httpRequest, HttpResponse.BodyHandlers.ofString());
    System.out.println(httpResponse.body());
  }
}

This code creates a new HTTP client, creates a new HTTP request with a URI pointing to example.com, sends the request synchronously, and finally, prints out the response body to the console. Note that the send method throws an exception, so it needs to be wrapped in a try-catch block or include a throws declaration.

The new HTTP Client API also supports asynchronous communication, which allows for more efficient use of resources and better performance. Here's an example of how to use the asynchronous version of the API:

import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.util.concurrent.CompletableFuture;

public class AsyncHttpClientExample {
  public static void main(String[] args) throws InterruptedException {
    HttpClient httpClient = HttpClient.newHttpClient();
    HttpRequest httpRequest = HttpRequest.newBuilder()
            .uri(URI.create("https://example.com"))
            .build();
    CompletableFuture<HttpResponse<String>> futureResponse = httpClient.sendAsync(httpRequest, HttpResponse.BodyHandlers.ofString());
    futureResponse.thenAccept(response -> System.out.println(response.body()));
    Thread.sleep(1000);
  }
}

This code is similar to the previous example, but instead of calling the send method, we call sendAsync to send the request asynchronously. The result of sendAsync is a CompletableFuture, which represents the eventual result of the operation. We call the thenAccept method on the CompletableFuture to print out the response body once it's received. Finally, we call Thread.sleep to wait for the response to arrive.

In conclusion, the new HTTP Client API in Java 11 is easy to use and supports both synchronous and asynchronous communication. Use these code examples as a starting point for exploring the new API and upgrading your Java skills!

Code Example 5: Multi-Release JAR Files

Multi-Release JAR files allow developers to package different versions of their code into one JAR file, making it easier to maintain and distribute their applications. This is especially useful when targeting multiple versions of Java, as it allows the same JAR file to contain different code depending on the version of Java being used.

To create a Multi-Release JAR file, start with a regular JAR file and add a "META-INF/versions" directory to the root of the JAR file. Within this directory, add subdirectories for each version of Java you want to target. For example, if you want to target Java 9 and above, you would add a subdirectory called "9". Then, within each subdirectory, add the version-specific code for that version of Java.

Here's an example of how this directory structure might look:

myapp.jar
├── com/example/MyClass.class
├── META-INF
│   ├── MANIFEST.MF
│   └── versions
│       ├── 9
│       │   └── com/example/MyClass.class
│       └── 11
│           └── com/example/MyClass.class

In this example, there is a single main class called MyClass, but there are two versions of the class – one for Java 9 and one for Java 11. When the JAR file is run on a Java 9 or Java 10 runtime, it will use the version-specific class in the META-INF/versions/9 directory. When run on a Java 11 or later runtime, it will use the version in the META-INF/versions/11 directory.

To build a multi-release JAR file using Maven, add the following configuration to your pom.xml:

<build>
  <plugins>
    <plugin>
      <groupId>org.apache.maven.plugins</groupId>
      <artifactId>maven-jar-plugin</artifactId>
      <version>3.2.0</version>
      <configuration>
        <archive>
          <manifestEntries>
            <Multi-Release>true</Multi-Release>
          </manifestEntries>
        </archive>
      </configuration>
    </plugin>
  </plugins>
</build>

This configuration adds the Multi-Release attribute to the JAR file's manifest, indicating that it is a multi-release JAR file.

With this setup, you can now write your code to take advantage of new language features in newer versions of Java, while still maintaining compatibility with older versions. Give it a try and see how it can simplify your application distribution!

Code Example 6: Interface Private Methods

Java 9 introduced a new feature called "private interface methods". These are methods that can only be accessed within the interface itself, and not by any implementing classes.

Why is this important? Well, it allows us to write more modular and reusable code. We can now define common behavior in a private interface method, which can then be called by multiple public methods within the interface.

Here's a simple example:

public interface MyInterface {
    default void publicMethod() {
        privateMethod();
    }
    
    private void privateMethod() {
        System.out.println("This is a private method");
    }
}

In this example, we have a public method called "publicMethod", which calls a private method called "privateMethod". The private method can only be accessed within the interface itself, so any implementing classes can't access it directly.

Note that private interface methods can also use private fields and other private methods within the interface.

Overall, private interface methods are a useful addition to Java 9 and can help us write cleaner and more modular code.

Conclusion and Download Java 11 for 64-bit Systems

Congratulations! You have learned some new Java skills with the top code examples we provided. To continue your journey and keep your skills sharp, we recommend you upgrade to the latest version of Java – Java 11 for 64-bit systems.

To download Java 11, head to the Oracle website and select the appropriate version for your operating system. Once installed, you'll be ready to experiment and broaden your Java knowledge.

Remember, the key to learning Java – or any programming language – is to practice, practice, practice. Don't be afraid to try out new things and make mistakes. That's how you'll learn what works and what doesn't.

As you continue to learn, we suggest staying up-to-date with the latest news and trends in the Java community. Subscribe to blogs and social media sites to keep informed about new features and best practices. And always remember, it's better to start with the basics and work your way up. Don't get distracted by buying books or using complex IDEs too soon; focus on mastering the foundations of the language first.

We hope these tips help you continue to improve your Java skills and reach new heights in your programming journey. Happy coding!

My passion for coding started with my very first program in Java. The feeling of manipulating code to produce a desired output ignited a deep love for using software to solve practical problems. For me, software engineering is like solving a puzzle, and I am fully engaged in the process. As a Senior Software Engineer at PayPal, I am dedicated to soaking up as much knowledge and experience as possible in order to perfect my craft. I am constantly seeking to improve my skills and to stay up-to-date with the latest trends and technologies in the field. I have experience working with a diverse range of programming languages, including Ruby on Rails, Java, Python, Spark, Scala, Javascript, and Typescript. Despite my broad experience, I know there is always more to learn, more problems to solve, and more to build. I am eagerly looking forward to the next challenge and am committed to using my skills to create impactful solutions.

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