What you will need

• The latest Android SDK
• At least version 1.5 of the Java Developer Kit. (type @java -version@ into your terminal or command prompt to find out the version you have).
• About 10 minutes of time

Setting Up

1. Follow the instructions on the Android SDK installation page making sure you follow the steps for adding the tools directory to your path. In my case I put the SDK into ~/Code/Android (where ~/ is my home directory).
2. Restart your command prompt or terminal and type android. You should be presented with the android help information. If not check you set the path correctly.

Target Platforms and Android Virtual Devices (AVDs)

It is possible to create emulators (AVDs) for each version (or target) of Android. To do this we need to check which hardware targets are available and what their target ID is. If you type android list targets into your terminal you will be presented with something similar to the code below.

Available Android targets:
id: 1
     Name: Android 1.1
     Type: Platform
     API level: 2
     Skins: HVGA (default), HVGA-L, HVGA-P, QVGA-L, QVGA-P
id: 2
     Name: Android 1.5
     Type: Platform
     API level: 3
     Skins: HVGA (default), HVGA-L, HVGA-P, QVGA-L, QVGA-P
id: 3
     Name: Google APIs
     Type: Add-On
     Vendor: Google Inc.
     Description: Android + Google APIs
     Based on Android 1.5 (API level 3)
     Libraries:
      * com.google.android.maps (maps.jar)
          API for Google Maps
     Skins: HVGA (default), HVGA-L, QVGA-P, HVGA-P, QVGA-L

From this information we can see the SDK supports Android 1.1 and 1.5 and their target IDs are 1 and 2 respectively. Knowing this information we can now create our Android Virtual Device. To create an AVD for Android 1.1 (target ID 1) with the name android1.1 we type:

android create avd -n android1.1 -t 1

Similarly for Android 1.5 we type:

android create avd -n android1.5 -t 2

A few things to know about AVDs. * When creating AVDs you can use any name you like. I choose android1.1 and android1.5 as they were easier to remember. * When prompted about hardware settings just press enter as there should be no need to customise the hardware when testing websites. * AVDs are created in a hidden folder in the root of your home directory. On Linux and MacOS this is ~/.android/avd. * You can find out what AVDs you have by typing android list avd in the terminal.

Running the Emulator

Having created the AVDs we can now run the emulator by typing emulator -avd avdname. This command is the one you will need to use from now on if you want to test websites in Android. For example, if we want to emulate Android 1.1 we would type:

emulator -avd android1.1

The first time you run the emulator you will be asked if you are happy for Emulator to send usage statistics to Google.

It can take about 10-30 seconds for the Android Emulator to boot up. During this time you will see the Android boot screen.

That’s it! To test your websites just load the Browser from the home screen. To enter a URL click Menu and then select Go or Go to URL depending on the version of Android you are running.

The answer is remarkably simple and allows you to test any site hosted on your local machine with browsers installed on your virtual machines. In all of this I am assuming your running Mac OS X and Windows XP in the virtual machine. That being said, as long as your know your hosts IP address and the virtual machine is running Windows 95 upwards this will work. By host I mean the machine which you run VMWare or Parallels on.

What you need

• A virtual machine application such as VMWare or Parallels
• A website hosted on your local machine

What to do

With your virtual machine turned off, edit it’s settings to ensure it is running the Network card in “Bridged” mode. What this does is allow your virtual machine to appear on your network as if it was another computer, rather that the default NAT mode that hides the virtual machine behind the hosts IP address.

Next start up your virtual machine and whilst it’s loading, make a note of the hosts IP address. You can find your IP address in the network preferences or through the command ipconfig (Windows) or ifconfig (Linux and Mac).

With the virtual machine now loaded go to Start > Run and type notepad "c:\windows\system32\drivers\etc\hosts". This will load up the file Windows uses to alias IP addresses to host names.

The file is very well explained but in a nutshell, you put the IP address of the host at the beginning of the line, and the domain name that should point to it. So, lets assume my host IP is 10.0.1.97 and the domain I am developing is www.themattharris.com. In the hosts file I would enter a new line as

10.0.1.97       www.themattharris.com

Now lets assume i’m also developing another domain on the host called www.tokofu.com. All I need to do is add another line to the hosts file 

10.0.1.97       www.tokofu.com

Save the file and test in your virtual machine. The domains you entered into the Windows hosts file will have caused your web browser to request the site from your host and not the Internet.

We can also validate this by running two commands in the Windows Command Prompt. If we run nslookup the computer will lookup the domain name using a DNS server. If we run the command ping Windows instead uses the address it knows from the hosts file. You can see this by loading a command prompt (Start > Run and type cmd ) and entering nslookup your-domain.com and ping your-domain.com

To restore the default behaviour you edit the “c:\windows\system32\drivers\etc\hosts” file and either delete the lines you entered, or start the line with a # (this marks the line as a comment).