First Cucumber+java+maven project.

Prerequisite: following should be installed:

• Java
• Eclipse
• Maven
• maven-eclipse-plugin
• Cucumber-eclipse-plugin

Step 1) Lets create a new project in eclipse by following steps:

Click on new –> Other –> Maven –> Maven Project — > Next

Step 2) Now click on Simple project and keep the default workspace location.

Step 3) Provide details as Artifact id, Group id, name and description. and click on Finish.

Step 4) This should create a basic maven project. 

Create packages as shown in the below snapshot and create new files in the project.

Feature file:

Feature:  Adding numbers with a Calculator
  In order to not learn math
  As someone who is bad at math
  I want to be able to add numbers using a Calculator
  
  Scenario:  Add two positive numbers
    Given I have a Calculator
    When I add 1 and 1
    Then the sum should be 2
    
  Scenario:  Add a positive and negative number
    Given I have a Calculator
    When I add 1 and -1
    Then the sum should be 0
    
  Scenario:  Add two negative numbers
    Given I have a Calculator
    When I add -1 and -1
    Then the sum should be -2

Runner.java:

@CucumberOptions

(

features = "src/test/resources/featurefile/caclculator.feature",
glue = {"com.steps"},
plugin = {"pretty", "com.cucumber.listener.ExtentCucumberFormatter:target/cucumber-reports/report.html"},
tags={"~@ignore"} 
)

This class responsible for reading the features file 

Feature -- link of feature file

Glue Tag -- This holds the package containing steps

Plugin -- any report plugin you want to add.

Tags -- if you want to test specific tags methods like @functional @regression

package com.feature;

import org.junit.AfterClass;
import org.junit.runner.RunWith;

import com.cucumber.listener.Reporter;

import cucumber.api.CucumberOptions;
import cucumber.api.junit.Cucumber;

@RunWith(value = Cucumber.class)
@CucumberOptions

(features = "src/test/resources/featurefile/caclculator.feature",
glue = {"com.steps"},
plugin = {"pretty", "com.cucumber.listener.ExtentCucumberFormatter:target/cucumber-reports/report.html"},
tags={"~@ignore"} 
)
public class Runnner {

    @AfterClass
    public static void writeExtentReport() {
        Reporter.setSystemInfo("Machine", "Windows 7:-" + "64 Bit");
        Reporter.setSystemInfo("Maven", "3.5.2");
        Reporter.setSystemInfo("Java Version", "1.8.0_151");
    }
}

CalculatorSteps.java :

package com.steps;

import static org.junit.Assert.assertEquals;

import com.feature.Calculator;

import cucumber.api.java.en.Given;
import cucumber.api.java.en.Then;
import cucumber.api.java.en.When;


public class CalculatorSteps {

 private Calculator calculator;

 private int actualSum;

        //  ^ - denotes start of string in feature file given statement
 //  $ - denotes end of string in feature file given statement

 @Given("^I have a Calculator$")
 public void intializeCalculator() {
  this.calculator = new Calculator();
 }

        //  ^ - denotes start of string in feature file when statement
 //  $ - denotes end of string in feature file when statement

        //  (-?\\d)  denotes the parameter in number format

 @When("^I add (-?\\d) and (-?\\d)$")
 public void whenIAddTwoNumbers(int firstNumber, int secondNumber) {
  this.actualSum = this.calculator.add(firstNumber, secondNumber);
 }

 @Then("^the sum should be (-?\\d)$")
 public void thenTheSumShouldBe(int expectedSum) {
  assertEquals("The expected sum does not equal the actual sum", expectedSum, this.actualSum);
 }
}

Calcuator.java:

This class is our main class which we need to test using our feature file.This contains our logical code generally.

package com.feature;

public class Calculator {

 public int add(int firstNumber, int secondNumber) {
  return firstNumber + secondNumber;
 }
}

Pom.xml :

<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.practise</groupId>
 <artifactId>cucumber</artifactId>
 <version>0.0.1-SNAPSHOT</version>
 <description> </description>
 <properties>
  <cucumber.version>0.3.2</cucumber.version>
  <file.encoding>UTF-8</file.encoding>
  <java.version>1.8</java.version>
 </properties>
 <build>
  <plugins>
   <plugin>
    <artifactId>maven-compiler-plugin</artifactId>
    <version>2.3.2</version>
    <configuration>
     <source>${jdk.version}</source>
     <target>${jdk.version}</target>
     <encoding>${file.encoding}</encoding>
    </configuration>
   </plugin>
  </plugins>
 </build>
 <dependencies>
  <dependency>
   <groupId>org.springframework</groupId>
   <artifactId>spring-context</artifactId>
   <version>2.5.6</version>
   <scope>test</scope>
  </dependency>
  <dependency>
   <groupId>junit</groupId>
   <artifactId>junit</artifactId>
   <version>4.12</version>
   <scope>test</scope>
  </dependency>
  
  
  <!-- Cucummber dependencies -->
  
  <dependency>
            <groupId>info.cukes</groupId>
            <artifactId>cucumber-junit</artifactId>
            <version>1.2.5</version>
        </dependency>
        <dependency>
            <groupId>info.cukes</groupId>
            <artifactId>cucumber-java</artifactId>
            <version>1.2.5</version>
        </dependency>
        
         <!-- https://mvnrepository.com/artifact/com.vimalselvam/cucumber-extentsreport -->
        <dependency>
            <groupId>com.vimalselvam</groupId>
            <artifactId>cucumber-extentsreport</artifactId>
            <version>3.0.2</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/com.aventstack/extentreports -->
        <dependency>
            <groupId>com.aventstack</groupId>
            <artifactId>extentreports</artifactId>
            <version>3.1.2</version>
        </dependency>
  
 </dependencies>

</project>

As  you addded all these class and files now time to run the application

open class Runner and rightclick ->run as -->Junit test

You will see this on screen with all passing test cases.

Flow diagram of cucumber test.