Book Image

Building Microservices with Spring

By : Dinesh Rajput, Rajesh R V
Book Image

Building Microservices with Spring

By: Dinesh Rajput, Rajesh R V

Overview of this book

Getting Started with Spring Microservices begins with an overview of the Spring Framework 5.0, its design patterns, and its guidelines that enable you to implement responsive microservices at scale. You will learn how to use GoF patterns in application design. You will understand the dependency injection pattern, which is the main principle behind the decoupling process of the Spring Framework and makes it easier to manage your code. Then, you will learn how to use proxy patterns in aspect-oriented programming and remoting. Moving on, you will understand the JDBC template patterns and their use in abstracting database access. After understanding the basics, you will move on to more advanced topics, such as reactive streams and concurrency. Written to the latest specifications of Spring that focuses on Reactive Programming, the Learning Path teaches you how to build modern, internet-scale Java applications in no time. Next, you will understand how Spring Boot is used to deploying serverless autonomous services by removing the need to have a heavyweight application server. You’ll also explore ways to deploy your microservices to Docker and managing them with Mesos. By the end of this Learning Path, you will have the clarity and confidence for implementing microservices using Spring Framework. This Learning Path includes content from the following Packt products: • Spring 5 Microservices by Rajesh R V • Spring 5 Design Patterns by Dinesh Rajput
Table of Contents (22 chapters)
Title Page
About Packt

Understanding AOP proxies

As you know that, Spring AOP is proxy-based. It mean Spring creates the proxy to weave the aspect between the business logic that is, in target object. It is based on the Proxy and Decorator design pattern. Let's see TransferServiceImpl class as an implementation of TransferService interface:

    package com.packt.patterninspring.chapter6.bankapp.service; 
    import org.springframework.stereotype.Service; 
    public class TransferServiceImpl implements TransferService { 
      public void transfer(String accountA, String accountB, Long 
      amount) { 
        System.out.println(amount+" Amount has been tranfered from 
        "+accountA+" to "+accountB); 

Caller invokes this service (transfer() method) directly by the object reference, let's see the following figure to illustrate more:

As you can see that caller could directly call the service and do the task assigned to it.

But you declare this TransferService as a target for the...