Project 3: Android Studio (20 points)

Windows Problems

Several students found the emulator to be so slow on Windows that it was impossible to use. If that happens, use Genymotion instead. I added a note later in the project to show you when to do that.

Mac OS X Issue

After installing Android Studio, I couldn't start VMware Fusion virtual machines on my Mac--I got this error:
Could not open /dev/vmmon: No such file or directory.
This problem is caused by the Intel Hardware Accelerated Execution Manager (HAXM).

One workaround is to restart the Mac. After a restart, VMware Fusion works.

Another workaround is to unload the Intel HAXM module with this Terminal command:

sudo kextunload -b
There are several links at the end of this project explaining Intel HAXM.

What You Need for This Project


Android Studio is Google's software development environment for Android.

It's essential for creating, debugging, and testing Android apps.

Downloading Android Studio

Follow the instructions on the Web page to download and install Android Studio for your OS. The Mac version is 234 MB in size, but the Windows version is 828 MB.

Troubleshooting: Missing Java SDK

During the installation, you may see an error message saying that you need the Java SDK, as shown below.

Installing Java SDK

If JDK was not detected, as shown above, you need to fix that.

In the Android Studio Setup Wizard, click the blue link.

Download the correct Java SDK for your OS, as shown below.

Install the Java SDK, with the default options.

Resuming the Android Studio Setup

If you are using a Mac, in the Android Studio Setup Wizard, click Previous and then Next. If you are using a PC, cancel the installation and start it from the beginning again.

Install Android Studio with the default options.

Accept all the license agreements, of course.

It's a long process, with a lot of files downloaded and installed.

Writing an App

When the install finishes, Android Studio launches.

You should see the "Welcome to Android Studio" screen, as shown below.

On the right side, click "Start a new Android Studio project", as shown below.

In the "New Project" screen, enter an Application name of YOURNAME-hello, as shown below.

Don't use the literal text "YOURNAME" -- replace that with your own name.

Click Next.

The next screen asks which versions of Android you are targeting, as shown below.

Accept the default selection and click Next.

In the "Add an activity to Mobile" screen, accept the default selection of "Blank Activity" as shown below, and click Next.

In the "Choose options for your new file" screen, accept the default selections as shown below, and click Finish.

If you are using Windows, it will spend several minutes "Indexing".

Other messages go by, initializing things and "Building".

When all that stuff is done, a project page appears, as shown below.

If "Windows Firewall" boxes pop up, approve Java to access the Internet.

If a "Tip of the day" pops up, close it.

If a "Rendering problems" box appears, close it.

However, if a "Gradle project sync failed" message appears, as shown above, that means you have errors that matter, probably Java errors.

Resolving Java Errors

On my PC, Java worked! But that is a very rare exception.

Java fails to work most of the time. It is maddening, but there's no way to escape it.

The most common problem is that the Java files are installed in a directory that the application cannot find. It's been this way for many years, and somehow Java never fixes it.

Here's what I did, but your errors will probably be different. Expect this to take time and a lot of Googling.

In my case, there is a yellow bar saying "Gradle project sync failed...", and a pop-up box titled "Language Level Changed", as shown above.

In the pop-up box titled "Language Level Changed", click Yes.

The project reloads. Now the lower pane shows some Java error messages, as shown below.

Open a Terminal window, and execute this command:

The response tells you where Java is installed, as shown below.

On my Mac, Java is installed at


In the lower pane of Android Studio, click "Open SDK Settings".

As you can see below, the "JDK location" is wrong.

Copy and paste in the correct location, as shown below.

Then click OK.

Android Studio displays a yellow bar at the top, saying "Gradle sync in progress".

After that, the "Language Level Changed" box pops up again. Click Yes.

Exploring your App

When the Java problems are fixed, your project loads without errors, as shown below.

The left pane shows the files in your app.

A much easier way to control your app is to use the right pane. Click the activity_main.xml tab.

The center now shows the screen of a phone, showing "Hello world!" in tiny letters, as shown above. This is a graphical view of how your app will look on a phone.

Customizing your App

In the upper right of the Android Studio window, in the "Component Tree" section, click "TextView - @string/hello_world".

In the lower right of the Android Studio window, in the Properties section, scroll down to textSize and change the size to 40. Press Enter. The "Hello world" text gets larger, as shown below.

On the phone face, double-click "Hello world".

A little box appears with a "text" field containing "@string/hello_world", as shown below.

Replace the "@string/hello_world" text with this text:

Hello from YOUR NAME

Use your own name, not the literal text "YOUR NAME".

In the "id" field, enter

Replace "YOURNAME" with your own name, without any embedded spaces, as shown below.

Press Enter.

The phone face should now show the revised message containing your name, as shown below.

Using the Emulator

The next step is to run your app on an emulated Android device.

From the Android Studio menu bar, click Tools, Android, "AVD Manager", as shown below.


If there is no "Android" item in the Tools menu, Android Studio is still loading. You need to wait a few more minutes.
You may see two devices, as shown below, or only one.

In the "Nexus 5" line, click the green right-arrow.

An emulated Nexus 5 phone launches, and a home screen appears, as shown below.

Notes for Windows Users

If the emulator does not work, which is very common on Windows machines, you can either try to troubleshoot it with fixes like the next three "Troubleshooting" steps, or stop at this point and do the first section of project 1x to install Genymotion. Genymotion is a much better emulator.


If you see this error message:

emulator: ERROR: x86 emulation currently requires hardware acceleration!  
Please ensure Intel HAXM is properly installed and usable.  
CPU acceleration status: HAX kernel module is not installed!  
The solution is here:


If you see this error message:

emulator: WARNING: requested RAM is too large for your environment 
In "AVD Manager", click the pencil icon in the Actions column, click "Show Advanced Settings", and scroll down to find the RAM setting. Set the RAM to 750 MB, and the VM heap to 128 MB, as shown below.

NOTE: On a PC, you need to scroll to the right to see the MB label.

Close Android Studio and restart it.


If the Android device launches, showing a black screen, and never shows "ANDROID", go into Windows Update, Optional Updates, and update the Display driver, as shown below.

This helped when working in S214.

Starting your App

From the Android Studio menu bar, click Run, "Run 'app'".

A box pops up, asking you to "Choose a running device", as shown below.

Accept the default selection of "Emulator Nexux 5", as shown below, and click OK.

In the emulated Android device, click, hold down the moust button, and swipe up to unlock.

Your emulated device shows your App running, as shown below.


Android Adventures - Getting Started With Android Studio

stackoverflow: Error:compileSdkVersion android-21 requires compiling with JDK 7

IntelĀ® Hardware Accelerated Execution Manager

Installation Instructions for IntelĀ® Hardware Accelerated Execution Manager - Mac OS X*

Fusion 5 - Could not open devvmmon: No such file or directory.

Last modified 7-29-15