Topic

Groovy

A collection of 54 issues

Groovy Scripts - Reusable Code

Let's start with the following Groovy script which reads and prints all the properties from a file. import java.nio.file.Path Properties loadProperties() { Properties properties = new Properties() Path propertyFilePath = Path.of('my.properties') propertyFilePath.withInputStream { properties.load(it) } properties } Properties properties = loadProperties() properties.each { println

Effective Java with Groovy - Immutability

It would seem like mutability is the default design approach when it comes to Java. However, reading "Effective Java" makes you change your mind. The book suggests - 'minimise mutability'. Also, what is highly useful is the reason for favouring immutability - "immutability is simple&

Effective Java with Groovy - The (in)famous null

If you have seen some of the enterprise applications written in Java, you know the amount of code goes into performing null checks. The 'null reference' feature of Java for sure is the #1 contributor to employment generation. The creator of null reference has already admitted that it

Effective Java with Groovy - Enabling Order

This post shows how does Groovy make it convenient for you to implement Comparable and Comparator interfaces.

Micronaut HTTP Client - Error Flow

We have seen Micronaut BlockingHttpClient in action and how to use exchange and retrieve methods to interact with an HTTP endpoint. What happens if your endpoint returns HTTP status code greater than or equal to 400 (they indicate that it's an error)? To explore this, let's

Groovy Scripts - Exploring Binding

In a previous post exploring scripting basics, we saw how binding was used to supply command-line arguments to scripts. In this post, let's explore the design of binding further. class BindingDemo { static void main(String[] args) { Binding sampleBinding = new Binding() println sampleBinding.variables sampleBinding.message = "Hello"

Effective Java with Groovy - Favour Internal Iterators

Let's start with the following code making use of the traditional for loop. List<String> languages = List.of("Java", "Groovy", "Kotlin"); // List.of() requires Java 9 or above for (int i = 0; i < languages.size(); i++) { System.out.println(

Groovy Scripts - Functions and Variables

In a previous post, we explored the simplicity of scripting mode offered by Groovy. We arrived at the following code. String message = args.length > 0 ? "Hello ${args[0]}" : "Hello" println message Let's make the functionality slightly more sophisticated. Say, we want to send

Effective Java with Groovy - Are you implementing equals and hashCode correctly?

Consider the following Groovy code. class Product { String sku String description BigDecimal price } Now let's put the Product class into use as follows. Product book1 = new Product(sku: 'P101', description: 'Effective Java', price: 599.0) Product book2 = new Product(sku: 'P101', description:

Micronaut HTTP Client - just the response body

In a previous post, we used io.micronaut.http.client.BlockingHttpClient to get response from an HTTP endpoint. We used the exchange method as follows. HttpResponse response = client.toBlocking().exchange("/greeting", String) If you are using Java instead of Groovy, you will pass "String.class" instead