Maven publishing script for customising pom file generation

maven_publish.gradle

apply plugin: 'maven-publish'

afterEvaluate {
    publishing {
        publications {
            maven(MavenPublication) {
                groupId project.ext.pomGroupID
                artifactId project.name
                version project.ext.pomVersion

                artifact(bundleReleaseAar)
                pom.withXml {
                    final dependenciesNode = asNode().appendNode('dependencies')

                    ext.addDependency = { Dependency dep, String scope ->
                        if (dep.group == null || dep.version == null || dep.name == null || dep.name == "unspecified")
                            return // invalid dependencies should be ignored

                        final dependencyNode = dependenciesNode.appendNode('dependency')
                        dependencyNode.appendNode('artifactId', dep.name)

                        if (dep.version == 'unspecified') {
                            dependencyNode.appendNode('groupId', project.ext.pomGroupID)
                            dependencyNode.appendNode('version', project.ext.pomVersion)
                            System.println("${project.ext.pomGroupID} ${dep.name} ${project.ext.pomVersion}")
                        } else {
                            dependencyNode.appendNode('groupId', dep.group)
                            dependencyNode.appendNode('version', dep.version)
                            System.println("${dep.group} ${dep.name} ${dep.version}")
                        }

                        dependencyNode.appendNode('scope', scope)
                        // Some dependencies may have types, such as aar, that should be mentioned in the POM file
                        def artifactsList = dep.properties['artifacts']
                        if (artifactsList != null && artifactsList.size() > 0) {
                            final artifact = artifactsList[0]
                            dependencyNode.appendNode('type', artifact.getType())
                        }

                        if (!dep.transitive) {
                            // In case of non transitive dependency, all its dependencies should be force excluded from them POM file
                            final exclusionNode = dependencyNode.appendNode('exclusions').appendNode('exclusion')
                            exclusionNode.appendNode('groupId', '*')
                            exclusionNode.appendNode('artifactId', '*')
                        } else if (!dep.properties.excludeRules.empty) {
                            // For transitive with exclusions, all exclude rules should be added to the POM file
                            final exclusions = dependencyNode.appendNode('exclusions')
                            dep.properties.excludeRules.each { ExcludeRule rule ->
                                final exclusionNode = exclusions.appendNode('exclusion')
                                exclusionNode.appendNode('groupId', rule.group ?: '*')
                                exclusionNode.appendNode('artifactId', rule.module ?: '*')
                            }
                        }
                    }

                    configurations.api.getDependencies().each { dep -> addDependency(dep, "compile") }
                    configurations.implementation.getDependencies().each { dep -> addDependency(dep, "runtime") }
                }
            }
        }
        repositories {
            maven {
                url 'your_maven_url'
                credentials {
                    username your_user_name
                    password your_password
                }
            }
        }
    }
}

task cleanBuildPublishLocal(type: GradleBuild) {
    tasks = ['clean', 'build', 'publishToMavenLocal']
}

task cleanBuildPublish(type: GradleBuild) {
    tasks = ['clean', 'build', 'publish']
}

Where I need to put this code in gradle?
I have to put them in the Project Gradle or new file?

@Pjumpod somewhere into a separate file on the same level as your module's gradle script. You can use the name maven-publish.gradle for it as author did. Then don't forget to link it in your module's gradle with apply from: 'maven-publish.gradle'

Thanks for the GIST. One of my dependencies(for example: X) needs a custom repository to be declared. Can I add a custom repository into the generated pom.xml? So that users don't have to add X's repository into their project?

i use as you but just modify
repositories {
maven {
url 'https://repo.maven.apache.org/maven2/'
}
}

but when i publish got problem Failed to publish publication 'maven' to repository 'maven'

Could not PUT 'https://repo.maven.apache.org/maven2/com/bill24/24paymentsdk/24paymentsdk/1.0.0/24paymentsdk-1.0.0.aar'. Received status code 503 from server: client read error