Introduction
In this post, I will show you how to check whether a given date is first day of the month using Joda API. Joda API is a date time API which provides useful methods for data and time management in Java applications.
Prerequisites
Java 8 or 12, Joda API 2.10.3 (or 2.7), Junit 4.12
Build using Gradle
If you want to build application using gradle script – build.gradle, then you can use the following build script.
In the below build script we have included Joda API and Junit API for date time and running test cases respectively.
plugins {
id 'java-library'
}
sourceCompatibility = 12
targetCompatibility = 12
repositories {
mavenCentral()
jcenter()
}
dependencies {
implementation 'joda-time:joda-time:2.10.3'
testImplementation 'junit:junit:4.12'
}
Build using Maven
If you want to build the application using maven file – pom.xml, then you can use the following build file.
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.roytuts</groupId>
<artifactId>java-joda-api</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>java</name>
<url>http://maven.apache.org</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<jdk.version>1.8</jdk.version>
<joda.version>2.10.3</joda.version>
<junit.version>4.12</junit.version>
</properties>
<dependencies>
<!-- joda date time -->
<dependency>
<groupId>joda-time</groupId>
<artifactId>joda-time</artifactId>
<version>${joda.version}</version>
</dependency>
<!-- junit -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>${junit.version}</version>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>${jdk.version}</source>
<target>${jdk.version}</target>
</configuration>
</plugin>
</plugins>
</build>
</project>
Checking Day of Month
Create a utility class with utility method to check a given date is first day of month using Joda API.
package com.roytuts.joda;
import org.joda.time.DateTime;
public final class JodaDateUtils {
public static boolean isDateFirstDayOfTheMonth(final DateTime dateTime) {
return dateTime.getDayOfMonth() == 1;
}
}
Junit Testing
Create Junit test case to test the above method.
package com.roytuts.joda;
import org.joda.time.DateTime;
import org.joda.time.format.DateTimeFormat;
import org.joda.time.format.DateTimeFormatter;
import org.junit.Test;
public class JodaDateUtilsTest {
private final DateTimeFormatter dtf = DateTimeFormat.forPattern("dd-MM-yyyy");
@Test
public void testIsDateFirstDayOfTheMonth() {
DateTime dt = new DateTime();
System.out.println(JodaDateUtils.isDateFirstDayOfTheMonth(dt));
dt = dtf.parseDateTime("01-02-2016");
System.out.println(JodaDateUtils.isDateFirstDayOfTheMonth(dt));
dt = dtf.parseDateTime("01-01-2016");
System.out.println(JodaDateUtils.isDateFirstDayOfTheMonth(dt));
dt = dtf.parseDateTime("05-02-2016");
System.out.println(JodaDateUtils.isDateFirstDayOfTheMonth(dt));
}
}
Testing the Application
Run the above Junit class, you will get the below output:
false
true
true
false
Source Code
You can download source code.
Thanks for reading.