• Gradle installation
• Multi-project with Gradle

In this task you are going to create the same application as in Maven module, but with Gradle build tool.

1. After Gradle installation make sure that you have 'gradle' package with wrapper inside;
2. Open root settings.gradle file and add two modules: utils, demo.

Custom jar utils-1.3.5.jar will be created with the following instructions:

• The jar should contain class StringUtils with method boolean isPositiveNumber(String str).
• Apache Commons Lang 3.10 library is used to implement this method.

1. Open build.gradle in 'utils' and fill it with proper group, version and delete comments with proper implementation

plugins {
    // id for library
    // id for maven to publish jar to local repository
}

java {
// provide sourceCompatibility
}

repositories {
// provide repository, where required dependencies are located
}

publishing {
    publications {
        maven(MavenPublication) {
// provide groupId
// provide artifactId
// provide version

            from components.java
        }
    }
}

//add Apache Apache Commons Lang 3.10 (or higher) dependency

jar {
    manifest {
        //provide manifest with such attributes as 'Implementation-Title', 'Implementation-Version'
    }
}

2. Implement method in StringUtils.class:

public class StringUtils {
    public static boolean isPositiveNumber(String str) {
        //here magic will happen
    }
}

Now we will use the created util class:

1. Open build.gradle in 'demo' and fill in group, version, repositories and required dependency;

2. Provide required implementation:

public class Utils {
    public static boolean isAllPositiveNumbers(List<String> args) {
       //magic happens here
    }
}

Make sure that application passes all test suits.