How to add library in Gradle from Maven Central? - gradle

Question

I have an empty Android project, and I want to add some library to it.
For example, Picasso.
So I've edited 'app/build.gradle' and added follow line to the dependencies block:
dependencies {
compile 'com.android.support:support-v4:19.0.0'
compile 'com.android.support:appcompat-v7:19.0.0'
compile 'com.squareup.picasso:picasso:2.2.0'
compile fileTree(dir: 'libs', include: ['*.jar', '*.aar'])
}
Then I rebuilt my project. So now I want to use it, but Picasso classes is unavailable for Android Studio.
What did I miss?

Answer 1

After editing the build.gradle file by hand, you need to click the "Sync Project with Gradle Files" button before the IDE will pick up new dependencies.

Answer 2

I did it this way:
In Top build.gradle (Project: YourProject) I added:
buildscript {
repositories {
mavenCentral()
}
dependencies {
classpath 'com.h2database:h2:1.4.187'
//NOTE: you can get the latest version in http://mvnrepository.com/artifact/com.h2database/h2
}
}
allprojects {
repositories {
jcenter()
mavenCentral()
}
}
NOTE: I added this along with the predefined jcenter() repositories.
And then for my app/build.gradle file I added whichever library or dependency I needed on:
dependencies {
....//Add dependency here
}
I hope this can help!