[android] How to import Maven dependency in Android Studio/IntelliJ?

I've created a new Android project using the default wizard in Android Studio. Compiled, and deployed the app to my device. All is well.

Now I want to import an external library that is available on Maven. (http://square.github.io/picasso/). I went to module properties, and added a Maven library. It shows up correctly in the list of dependencies. In addition, it shows up in the editor and I can correctly use it in code.

However, at compile time, I get a Gradle error: unable to find class

Any ideas?

Try itext. Add dependency to your build.gradle for latest as of this post

Note: special version for android, trailing "g":

dependencies {
    compile 'com.itextpdf:itextg:5.5.9'
}

1. Uncheck "Offline work" in File>Settings>Gradle>Global Gradle Settings
2. Resync the project, for example by restarting the Android Studio
3. Once synced, you can check the option again to work offline.

Android Studio 3

The answers that talk about Maven Central are dated since Android Studio uses JCenter as the default repository center now. Your project's build.gradle file should have something like this:

repositories {
    google()
    jcenter()
}

So as long as the developer has their Maven repository there (which Picasso does), then all you would have to do is add a single line to the dependencies section of your app's build.gradle file.

dependencies {
    // ...
    implementation 'com.squareup.picasso:picasso:2.5.2'
}

I am using the springframework android artifact as an example

open build.gradle

Then add the following at the same level as apply plugin: 'android'

apply plugin: 'android'

repositories {
    mavenCentral()
}

dependencies {
   compile group: 'org.springframework.android', name: 'spring-android-rest-template', version: '1.0.1.RELEASE'
}

you can also use this notation for maven artifacts

compile 'org.springframework.android:spring-android-rest-template:1.0.1.RELEASE'

Your IDE should show the jar and its dependencies under 'External Libraries' if it doesn't show up try to restart the IDE (this happened to me quite a bit)

here is the example that you provided that works

buildscript { 
    repositories { 
        maven { 
            url 'repo1.maven.org/maven2'; 
        } 
    } 
    dependencies { 
        classpath 'com.android.tools.build:gradle:0.4' 
    } 
} 
apply plugin: 'android'

repositories {
    mavenCentral()
}

dependencies { 
    compile files('libs/android-support-v4.jar') 
    compile group:'com.squareup.picasso', name:'picasso', version:'1.0.1' 
} 
android { 
    compileSdkVersion 17 
    buildToolsVersion "17.0.0" 
    defaultConfig { 
        minSdkVersion 14 
        targetSdkVersion 17 
    } 
}