Developing a Sample HelloWorld Java Program by using Maven

Step1: Create a HelloWorld java project by using mvn command.

[ranga@ranga Documents]$ mvn archetype:generate -DgroupId=com.ranga -DartifactId=HelloWorld -DarchetypeArtifactId=maven-archetype-quickstart -DinteractiveMode=false

Project Structure looks like

HelloWorld
├── pom.xml
└── src
    ├── main
    │   └── java
    │       └── com
    │           └── ranga
    │               └── App.java
    └── test
        └── java
            └── com
                └── ranga
                    └── AppTest.java

9 directories, 3 files

Step2:

edit the pom.xml and add the following line to run a application  

<build>

    <plugins>

        <plugin>

        <artifactId>maven-compiler-plugin</artifactId>

        <version>2.0.2</version>

        <configuration>

                <source>1.6</source>

                <target>1.6</target>

        </configuration>

     </plugin>

        <plugin>

        <groupId>org.codehaus.mojo</groupId>

        <artifactId>exec-maven-plugin</artifactId>

        <configuration>

             <mainClass>com.ranga.App</mainClass>

        </configuration>

        </plugin>

    </plugins>

   </build>

 

Step3: Run the following command to compile and run. 




[ranga@ranga HelloWorld]$ mvn compile exec:java




Hello World!


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Developing a Simple HelloWorld Java Program by using gradle

Step 1: Create the following package Structure.

Java
    └──src
        ├── main
        │   ├── java       
        │   └── resources
        └── test
            ├── java
            └── resources

Step2: Inside src/main/java create a HelloWorld.java with the fowlloing package.

HelloWorld.java

package com.ranga;

public class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Hello World!");
    }
}

Now strutctue look likes

└── src
    ├── main
    │   ├── java
    │   │   └── com
    │   │       └── ranga
    │   │           └── HelloWorld.java
    │   └── resources
    └── test
        ├── java
        └── resources

Step3: Inside Java folder, create a new file called build.gradle parellel to src. 

Java
├── build.gradle
└── src
    ├── main
    │   ├── java
    │   │   └── com
    │   │       └── ranga
    │   │           └── HelloWorld.java
    │   └── resources
    └── test
        ├── java
        └── resources 

Step4: Add the plugin as 'java' and specify the main the class in the build.gradle file.

build.gradle
 
apply plugin: 'java'

task runHelloWorld(dependsOn: 'classes', type: JavaExec) {
    main = 'com.ranga.HelloWorld'
    classpath = sourceSets.main.runtimeClasspath
}

defaultTasks 'runHelloWorld'

Step5: In terminal enter the following command to run the Simple HelloWorld program.

[ranga@ranga java]$ gradle -q runHelloWorld
Hello, Ranga!


Another way is,


edit the build.gradle and the following line

apply plugin: 'application'

mainClassName = "com.ranga.HelloWorld"

Then run the following command in the terminal

[ranga@ranga java1]$ gradle -q run
Hello, Ranga!


Thats it............

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