Exploring the Latest Features of Java 13: A Hands-On Guide

Java, the popular programming language, has been evolving rapidly over the years with new features and enhancements being introduced in each version. Java 13, the latest version released in September 2019, brings several new features and improvements that make it easier and more efficient for developers to write code. In this hands-on guide, we will explore some of the key features of Java 13 and show you how to use them in your projects.

Switch Expressions

One of the highlight features of Java 13 is the introduction of switch expressions. Switch statements have been a core feature of Java since its inception, but they have always been limited to using them as a statement. With switch expressions, developers can now use switch as an expression, making the code more concise and readable.

Here’s an example of how you can use switch expressions in Java 13:

int day = 3;

String dayString = switch(day) {

    case 1, 2, 3, 4, 5 -> "Weekday";

    case 6, 7 -> "Weekend";

    default -> "Invalid day";

};

System.out.println(dayString);

In the above code snippet, we are using a switch expression to assign a value to the dayString variable based on the value of the day variable. This makes the code more readable and compact compared to traditional switch statements.

Text Blocks

Another useful feature introduced in Java 13 is text blocks. Text blocks allow developers to write multi-line strings in a more natural way without the need for escape characters or concatenation. This makes it easier to write and maintain complex strings in Java code.

Here’s an example of how you can use text blocks in Java 13:

String html = """

    <html>

        <head>

            <title>Java 13</title>

        </head>

        <body>

            <h1>Welcome to Java 13</h1>

        </body>

    </html>

""";

System.out.println(html);

In the above code snippet, we are using a text block to define an HTML string with multiple lines. This makes it easier to write and read the HTML content without the need for escape characters or concatenation.

Improvements in Garbage Collection

Java 13 also brings improvements in garbage collection with the introduction of two new features: ZGC (Z Garbage Collector) and Shenandoah GC. These new garbage collectors aim to reduce pause times and improve performance for applications with large heaps.

ZGC is a scalable low-latency garbage collector that can handle heaps ranging from a few gigabytes to several terabytes in size while keeping pause times within a few milliseconds. Shenandoah GC is another low-latency garbage collector that focuses on reducing pause times for applications with large heaps.

Developers can now use these new garbage collectors in Java 13 to improve the performance and scalability of their applications, especially for those running on large heaps.

Dynamic CDS Archives

Java 13 introduces dynamic CDS archives, which allow developers to generate a class data-sharing (CDS) archive at runtime. CDS archives contain precompiled classes and metadata that can be shared among multiple Java processes, reducing startup time and memory footprint.

With dynamic CDS archives, developers can create custom CDS archives at runtime based on the classes they use in their applications. This can help improve the startup time of Java applications by preloading classes and metadata from the archive, rather than parsing and loading them at runtime.

Conclusion

In this hands-on guide, we explored some of the key features of Java 13, including switch expressions, text blocks, improvements in garbage collection, and dynamic CDS archives. These new features make Java 13 a more powerful and efficient programming language for developers to use in their projects.

By leveraging these features, developers can write cleaner and more readable code, improve the performance and scalability of their applications, and reduce startup times and memory footprint. Java 13 continues to innovate and evolve, providing developers with the tools they need to build high-quality software efficiently.