mvn archetype:generate -DgroupId=com.yiibai -DartifactId=NumberGenerat
or -DarchetypeArtifactId=maven-archetype-quickstart -DinteractiveMode=false

mvn eclipse:eclipse

mvn package -DskipTests

java -cp target/NumberGenerator-1.0-SNAPSHOT.jar com.yiibai.App

<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/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.yiibai</groupId>
  <artifactId>NumberGenerator</artifactId>
  <packaging>jar</packaging>
  <version>1.0-SNAPSHOT</version>
  <name>NumberGenerator</name>
  <url>http://maven.apache.org</url>
  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
  </dependencies>
  <build>
      <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>2.3.2</version>
            <configuration>
                <source>1.8</source>
                <target>1.8</target>
            </configuration>
        </plugin>
      </plugins>
    </build>
</project>

package com.yiibai;

import java.util.UUID;

/**
 * Generate a unique number
 *
 */
public class App
{

    public static void main( String[] args )
    {
        App obj = new App();
        System.out.println("Unique ID : " + obj.generateUniqueKey());
    }

    public String generateUniqueKey(){

        String id = UUID.randomUUID().toString();
        return id;

    }
}