Book Image

Mastering the Java Virtual Machine

By : Otavio Santana
Book Image

Mastering the Java Virtual Machine

By: Otavio Santana

Overview of this book

Mastering the Java Virtual Machine is a comprehensive guide that will take you into the heart of Java programming, guiding you through the intricate workings of the Java Virtual Machine (JVM) and equipping you with essential skills to become a proficient Java developer. You’ll start by understanding the JVM, exploring its architecture and how it executes Java code. Through detailed explanations and real-world examples, you’ll gain a deep understanding of JVM internals, enabling you to write efficient and optimized Java applications. As you progress, you’ll delve into memory management and execution, unraveling the complexities of heap and stack management, garbage collection, and memory profiling. You'll learn how memory is allocated and reclaimed in the JVM, as well as how to optimize memory usage and identify performance bottlenecks in your applications. With this knowledge, you’ll be able to create Java programs that are not only robust but also highly performant. By the end of this book, you’ll have the skills needed to excel in Java programming, writing efficient, maintainable code.
Table of Contents (19 chapters)
Free Chapter
1
Part 1: Understanding the JVM
5
Part 2: Memory Management and Execution
9
Part 3: Alternative JVMs
12
Part 4: Advanced Java Topics

Exploring practical reflection

In this hands-on section, we delve into the practical application of Java’s Reflection API by creating a versatile Mapper interface. We aim to implement methods that dynamically convert objects of a given class to and from Map<String, Object>. The Mapper interface serves as a blueprint for a generic solution, allowing us to flex the muscles of reflection in a real-world scenario.

Let’s begin with the Mapper interface:

public interface Mapper {    <T> Map<String, Object> toMap(T entity);
    <T> T toEntity(Map<String, Object> map);
}

The toMap method is designed to convert an object of type T into a map, where each key-value pair represents a field name and its corresponding value. Conversely, the toEntity method reverses this process, reconstructing an object of type T from a given map.

Now, armed with the theory from the previous part, we’ll put reflection...