Difference among mavenCentral(), jCenter() and mavenLocal()?

Actually, I am studying on build.gradle file. In some cases, I got that sometimes they are using mavenCentral(), jCenter() and mavenLocal() in repositories section. Sometimes they also using URL. So some question arises in my mind?

i) Difference among mavenCentral(), jCenter() and mavenLocal()?

ii) Which one should I use most?

iii) Is there any performance related issue?

Solution 1:

Actually, all 3 are Maven repository. We use these maven repositories to our build by using its URL address or its location in the local file system.

By using URL:

repositories {
    maven { url("https://plugins.gradle.org/m2/") }
}

By using local file system:

repositories {
    maven { url '../maven-repo' }
}

Gradle has three “aliases” which we can use when we are adding Maven repositories to our build. These aliases are:

mavenCentral():

The mavenCentral() alias means that dependencies are fetched from the central Maven 2 repository.

repositories {
    mavenCentral()
}

The URL used to access this repository is https://repo.maven.apache.org/maven2/. The name of the repository is MavenRepo.

jcenter():

The jcenter() alias means that dependencies are fetched from the Bintray’s JCenter Maven repository

mavenLocal():

The mavenLocal() alias means that dependencies are fetched from the local Maven repository.

Resource Link:

Gradle: Dependency Management
Maven RepositoryHandler

Jcenter vs. mavenCentral

jcenter() and mavenCentral() is a repository for the Gradle plugin in Android Studio

Earlier versions of Android Studio used mavenCentral(), and after some time, it switched to jcenter.

This is because jcenter() is superior to mavenCentral() in terms of performance and memory footprint:

Jcenter is the world's largest Java repository
Jcenter through the CDN service, using the https protocol, highly secured, and Android Studio 0.8 version mavenCentral() using the http protocol
Jcenter is a superset of mavenCentral, including many additional jars
Jcenter performance is better than mavenCentral
mavenCentral will automatically download many IDE-related indexes, and these are used less often which are not required.

Resource Link： https://www.jianshu.com/p/bce437eeb3d3

Last Update: Into the Sunset on May 1st: Bintray, JCenter, GoCenter, and ChartCenter

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Update: 24-02-2021 of Android Developers Page:

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Announcement Link: https://jfrog.com/blog/into-the-sunset-bintray-jcenter-gocenter-and-chartcenter/

Maven Central Link: https://maven.apache.org/repository/index.html

Work Around:

repositories {
    mavenLocal()
    
//  jcenter()       // <- remove it
    mavenCentral()  // <- add it
    
    maven { url "https://plugins.gradle.org/m2/" }
    maven { url "https://repo.spring.io/plugins-release/" }
}

Solution 2:

As per Android Developer page -

JCenter deprecation and end of service

JFrog, the company that maintains the JCenter artifact repository used by many Android projects, recently announced the deprecation and upcoming retirement of JCenter. According to the announcement, JCenter will allow downloads of existing artifacts until February 1, 2022.

Developers who publish artifacts on JCenter should start migrating their packages to a new host, such as Maven Central.

Solution 3:

https://jfrog.com/blog/into-the-sunset-bintray-jcenter-gocenter-and-chartcenter/

UPDATE: To better support the community in this migration, JFrog has extended the JCenter new package versions submission deadline through March 31st 2021.

To clarify, the JCenter repository will keep serving packages for 12 months until February 1st 2022. Only the JCenter REST API and UI will be sunsetted on May 1st 2021.