plugin request for plugin already on the classpath must not include a version

问题

I've done web search for "plugin request for plugin already on the classpath must not include a version site:stackoverflow.com" and found nothing that particular. Search for "plugin request for plugin already on the classpath must not include a version" (w/out SO) found: https://discuss.gradle.org/t/error-plugin-already-on-the-classpath-must-not-include-a-version/31814 where I've read in answers e.g.:

I didn’t find any reference to this use case in Grade plugins documentation.

The error

Build file '/Users/username/github/OpCon/app/build.gradle' line: 4 Error resolving plugin [id: 'com.android.application', version: '3.4.1']

Plugin request for plugin already on the classpath must not include a version

appears in IntelliJ IDEA, build.gradle (OpCon):

buildscript {
    repositories {
        jcenter()
        maven {
            url 'https://maven.google.com/'
            name 'Google'
        }
        google()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.5.2'
        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        mavenCentral()
        maven { url "https://oss.sonatype.org/content/repositories/snapshots/" }
    }
    repositories {
        jcenter()
        maven {
            url 'https://maven.google.com/'
            name 'Google'
        }
    }
}
task clean(type: Delete) {
    delete rootProject.buildDir
}

app/build.gradle:

plugins {
    id 'com.android.application' version '3.4.1' apply true
}

... and then other stuff

I don't understand, classpath 'com.android.tools.build:gradle:3.5.2' does not seem to include 'com.android.application'... "classpath" has only one occurrence if searched in the project.

ADDED:

Interestingly on https://maven.google.com/web/index.html I can find 'com.android.tools.build:gradle:3.5.2' but no 'com.android.application' branch.

ADDED 2: I've downloaded (quite many files actually was downloaded for some reason) by command taken from here How can I download a specific Maven artifact in one command line?:

mvn org.apache.maven.plugins:maven-dependency-plugin:2.8:get -DrepoUrl='https://maven.google.com/' -Dartifact='com.android.tools.build:gradle:3.4.1'

found path com.android.tools.build:gradle in file manager and looked inside only jar there:

username$ jar tvf /Users/username/.m2/repository/com/android/tools/build/gradle/3.4.1/gradle-3.4.1.jar | grep application
  1115 Wed May 01 20:30:18 MSK 2019 com/android/build/gradle/internal/tasks/ApplicationIdWriterTask$applicationIdSupplier$1.class
    55 Wed May 01 20:29:18 MSK 2019 META-INF/gradle-plugins/com.android.application.properties

So there is a mention gradle plugin com.android.application in jar META-INF.

File com.android.application.properties is one liner: implementation-class=com.android.build.gradle.AppPlugin.

Web search for "implementation class java" finds info on interfaces. In wiki https://en.wikipedia.org/wiki/Interface_(Java):

An interface in the Java programming language is an abstract type that is used to specify a behavior that classes must implement.

So gradle plugin could be an interface? How can I dig in further?

回答1:

I was facing same problem, I was using spring boot with plugins as follows

plugins {
    id 'org.springframework.boot' version '2.2.0.RELEASE'
    id 'io.spring.dependency-management' version '1.0.8.RELEASE'
    id 'java'
    id 'war'
}

Since this plugin was present in one dependency gradle was complaining about it. I simply removed those dependencies and it worked:

plugins {
    id 'java'
    id 'war'
}

来源：https://stackoverflow.com/questions/60070739/plugin-request-for-plugin-already-on-the-classpath-must-not-include-a-version

标签

java

android

gradle