For your Android app to interact with the Guestbook portlet, you must install the following libraries in your Android project:
Liferay’s pre-built Mobile SDK: This Mobile SDK contains the classes that call Liferay Portal’s core remote services. It also contains the framework necessary for any Mobile SDK to make server calls.
The Guestbook Mobile SDK: This Mobile SDK contains only the classes that call the Guestbook portlet’s remote services.
Liferay Screens: Screens contains the Screenlet framework and several built-in Screenlets like Login Screenlet. Because these built-in Screenlets interact with Liferay Portal’s core apps, they make their server calls with Liferay’s pre-built Mobile SDK. Note that all Screenlets, including those that make server calls with a custom-built Mobile SDK, must use the framework in Liferay’s pre-built Mobile SDK to issue their calls.
Since Liferay’s pre-built Mobile SDK is a dependency of Liferay Screens, installing Screens automatically installs this Mobile SDK. You must, however, install the Guestbook Mobile SDK manually.
This article walks you through the installation of the Guestbook Mobile SDK and Liferay Screens. When you finish, you’ll be ready to start developing the app.
The Mobile SDK Builder generated two separate JAR files in your
The first JAR file is the Guestbook Mobile SDK. The second JAR file is a custom
built version of Liferay’s pre-built Mobile SDK. Because Screens includes the
pre-built Mobile SDK, you don’t need to install the second JAR file. You must,
however, install the first JAR file. To do so, copy
liferay-guestbook-portlet-android-sdk-1.0.jar into your app’s
folder (the default location for your Android app is
AndroidStudioProjects/LiferayGuestbook). That’s it! Next, you’ll install
To install Liferay Screens, you must edit your app’s
build.gradle file. Note
that your project has two
build.gradle files: one for the project, and another
for the app module. You can find them under Gradle Scripts in your Android
Studio project. This screenshot highlights the app module’s
In the app module’s
build.gradle file, add the following lines of code inside
This adds the
Although only the
liferay-screens dependency is necessary to install Screens,
adding other View Sets, like the Material View Set, gives you flexibility when
designing your app’s look and feel.
for more information on Views in Liferay Screens.
Once you edit
build.gradle, a message appears at the top of the file that asks
you to sync your app with its Gradle files. Syncing with the Gradle files is
required to incorporate any changes you make to them. Syncing also downloads and
installs any new dependencies, like those you just added. Sync the Gradle files
now by clicking the Sync Now link in the message.
Note that after syncing, your
build.gradle may show an error similar to this:
All com.android.support libraries must use the exact same version specification...
If this occurs, you must manually add the correct version of the
com.android.support dependencies. For example, the app in this Learning Path
currently uses version
25.3.1 of the
com.android.support libraries. This
requires that you manually add the following dependencies to the app’s
After adding these inside the
dependencies element, click Sync Now again.
The error message should be gone once the sync completes.
Great! Now you’re ready to test your Screens and Mobile SDK installations.
To check your Screens and Mobile SDK installations, first open your project’s
MainActivity class in Android Studio. It’s in the
com.liferay.docs.liferayguestbook package. Then add the following imports to
If Android Studio recognizes these imports, then you’re good to go! Remove them once you’ve verified that they’re valid. Next, there’s one final small but important task to complete: point your app at the correct Liferay Portal instance.
For Screens to work properly with your app, you must point it to your Liferay
Portal instance. You do this by adding a
server_context.xml file in your
res/values directory. Create this file and add the following code
<?xml version="1.0" encoding="utf-8"?>
<!-- Change these values for your portal instance -->
As the comment indicates, change the values to match those of your Liferay
Portal instance. The server address
http://10.0.2.2:8080 is suitable for
testing with Android Studio’s emulator, because it corresponds to
localhost:8080 through the emulator. The Liferay Portal instance you set up
earlier should be running on
liferay_company_id value is your Liferay Portal instance’s ID. You can
find it in the Control Panel → Configuration → Portal Instances
menu. Your portal instance’s ID is in the Instance ID column. Copy and paste
this value from your portal to the
liferay_company_id value in
liferay_group_id value is the ID of the site your app needs to communicate
with. Since the app needs to communicate with the Guestbook portlet, navigate to
the site you put the Guestbook portlet on. Then select
Admin → Site Administration → Configuration from the Dockbar.
The site ID is listed on the Site Settings tab. Copy and paste this value
from your portal to the
liferay_group_id value in
Awesome! Next, you’ll learn the app’s basic design.