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Currying in Java 1. Introduction Since Java 8, we can define one- and two-parameter functions in Java, allowing us to inject their behaviors into other functions, by passing them in as parameters. But for functions with more parameters, we rely on external libraries like Vavr. Another option is to use… Continue Reading java-currying
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Guide to Spring Cloud Stream with Kafka, Apache Avro and Confluent Schema Registry 1. Introduction Apache Kafka is a messaging platform. With it, we can exchange data between different applications at scale. Spring Cloud Stream is a framework for building message-driven applications. It can simplify the integration of Kafka into… Continue Reading spring-cloud-stream-kafka-avro-confluent
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Merging java.util.Properties Objects 1. Introduction In this short tutorial, we’ll focus on how to merge two or more Java Properties objects into one. We’ll explore three solutions, firstly starting with an example using iteration. Next, we’ll look into using the putAll() method and to conclude the tutorial, we’ll look at… Continue Reading java-merging-properties
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REST API Testing with Karate 1. Overview In this article, we’ll introduce Karate, a Behavior Driven Development (BDD) testing framework for Java. 2. Karate and BDD Karate is built on top of Cucumber, another BDD testing framework, and shares some of the same concepts. One of these is the use… Continue Reading karate-rest-api-testing
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Overriding System Time for Testing in Java 1. Overview In this quick tutorial, we’ll focus on different ways to override the system time for testing. Sometimes there’s a logic around the current date in our code. Maybe some function calls such as new Date() or Calendar.getInstance(), which eventually are going to… Continue Reading java-override-system-time
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Mockito ArgumentMatchers 1. Overview This tutorial shows how to use the ArgumentMatcher and how it differs from the ArgumentCaptor. For an introduction to the Mockito framework, please refer to this article. 2. Maven Dependencies We need to add a single artifact: <dependency> <groupId>org.mockito</groupId> <artifactId>mockito-core</artifactId> <version>2.21.0</version> <scope>test</scope> </dependency> The latest version of Mockito can be… Continue Reading mockito-argument-matchers
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A Custom Filter in the Spring Security Filter Chain 1. Overview In this quick article, we’ll focus on writing a custom filter for the Spring Security filter chain. Further reading: Spring Security – @PreFilter and @PostFilter Learn how to use the @PreFilter and @PostFilter Spring Security annotations through practical examples.… Continue Reading spring-security-custom-filter
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Java Weekly, Issue 253 Here we go… 1. Spring and Java ===== >> HTTP cache with Spring examples [dolszewski.com] A good write-up on optimizing applications via the HTTP response cache mechanism available for Spring Controllers. >> Should you adopt Java 12 or stick on Java 11? [blog.joda.org] Before jumping on the new… Continue Reading java-weekly-253
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Java String.charAt() Java The method charAt() returns the character at the specified index. The index value must be between 0 and String.length() – 1. Available Signatures public char charAt(int index) Example @Test public void whenCallCharAt_thenCorrect() { assertEquals(‘P’, “Paul”.charAt(0)); } Throws IndexOutOfBoundsException – if a non-existent or a negative index is… Continue Reading string-char-at
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Java String.codePointCount() Java Java String The method codePointCount() returns the number of Unicode code points in the specified range. The text range begins at the first index and ends at the second index – 1. Available Signatures public int codePointCount(int beginIndex, int endIndex) Example @Test public void whenCallCodePointCount_thenCorrect() { assertEquals(2,… Continue Reading string-code-point-count
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