build.gradle

// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.3.1'

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

subprojects {

    task allTask2 {
        doLast {
            println '--------'
            println project.name
        }

    }

}

allprojects {
    repositories {
        jcenter()
    }

    apply plugin: 'idea'


    task allTask {
        doLast {
            println project.name
        }

    }
}

configure(allprojects.findAll { it.name.startsWith('java') }) {
    allTask2  {
        doLast{
            println 'this is a sub project'
        }

    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

project(':javalibgradletest') {
    task forProject1  {
        println 'for project 1'
    }
}