Show UML Class Diagrams on Javadoc

javadoc-uml.build

//
// Override the javadoc task to use umlgraph doclet.  This depends on the presence
// of GraphViz on the path in your environment (http://www.graphviz.org)
//
allprojects {
    configurations {
        umljavadoc
    }

    dependencies {
        umljavadoc 'org.umlgraph:umlgraph:5.6'
    }

    //
    // While javadoc is not typically dependent on compilation, the compile steps
    // sometimes generate some sources that we wish to have in the Javadoc.
    //
    task javadoc(overwrite: true, dependsOn: compileJava) {
        setDescription('Generates Javadoc API documentation with UMLGraph diagrams')
        setGroup(JavaBasePlugin.DOCUMENTATION_GROUP)

        doLast {
            def javaFilePath = file('src/main/java')
            if (javaFilePath.exists()) {
                ant.javadoc(classpath: (configurations.runtime + configurations.provided).asPath, 
                            sourcepath: file('src/main/java'), 
                            packagenames: '*',
                            destdir: "${docsDir}/javadoc",
                            private: 'true',
                            docletpath: configurations.umljavadoc.asPath) {
                    doclet(name: 'org.umlgraph.doclet.UmlGraphDoc') {
                        param(name: '-inferrel')
                        param(name: '-inferdep')
                        param(name: '-qualify')
                        param(name: '-postfixpackage')
                        param(name: '-hide', value: 'java.*')
                        param(name: '-collpackages', value: 'java.util.*')
                        param(name: '-nodefontsize', value: '9')
                        param(name: '-nodefontpackagesize', value: '7')
                        param(name: '-link', value: 'https://docs.oracle.com/javase/8/docs/api')
                    }
                }
            }
        }
    }
}