Managing Projects from the Command Line

The android tool provides you with commands to create all three types of projects. An Android project contains all of the files and resources that are needed to build a project into an .apk file for installation.

• An Android project contains all of the files and resources that are needed to build a project into an .apk file for installation. You need to create an Android project for any application that you want to eventually install on a device.
• You can also designate an Android project as a library project, which allows it to be shared with other projects that depend on it. Once an Android project is designated as a library project, it cannot be installed onto a device.
• Test projects extend JUnit test functionality to include Android specific functionality. For more information on creating a test project, see Testing from other IDEs .

Creating an Android Project

To create an Android project, you must use the android tool. When you create a new project with android , it will generate a project directory with some default application files, stub files, configuration files and a build file.

To create a new Android project, open a command-line, navigate to the tools/ directory of your SDK and run:

       android create project \
--target <target_ID> \
--name <your_project_name> \
--path path/to/your/project \
--activity <your_activity_name> \
--package <your_package_namespace>
      

• target is the "build target" for your application. It corresponds to an Android platform library (including any add-ons, such as Google APIs) that you would like to build your project against. To see a list of available targets and their corresponding IDs, execute: android list targets .
• name is the name for your project. This is optional. If provided, this name will be used for your .apk filename when you build your application.
• path is the location of your project directory. If the directory does not exist, it will be created for you.
• activity is the name for your default Activity class. This class file will be created for you inside <path_to_your_project> /src/ <your_package_namespace_path> / . This will also be used for your .apk filename unless you provide a name .
• package is the package namespace for your project, following the same rules as for packages in the Java programming language.

Here's an example:

       android create project \
--target 1 \
--name MyAndroidApp \
--path ./MyAndroidAppProject \
--activity MyAndroidAppActivity \
--package com.example.myandroid
      

Once you've created your project, you're ready to begin development. You can move your project folder wherever you want for development, but keep in mind that you must use the Android Debug Bridge (adb) — located in the SDK platform-tools/ directory — to send your application to the emulator (discussed later). So you need access between your project solution and the platform-tools/ folder.

Tip: Add the platform-tools/ as well as the tools/ directory to your PATH environment variable.

Caution: You should refrain from moving the location of the SDK directory, because this will break the SDK location property located in local.properties . If you need to update the SDK location, use the android update project command. See Updating a Project for more information.

Updating a Project

If you're upgrading a project from an older version of the Android SDK or want to create a new project from existing code, use the android update project command to update the project to the new development environment. You can also use this command to revise the build target of an existing project (with the --target option) and the project name (with the --name option). The android tool will generate any files and folders (listed in the previous section) that are either missing or need to be updated, as needed for the Android project.

To update an existing Android project, open a command-line and navigate to the tools/ directory of your SDK. Now run:

       android update project --name <project_name> --target <target_ID>
--path <path_to_your_project>
      

• target is the "build target" for your application. It corresponds to an Android platform library (including any add-ons, such as Google APIs) that you would like to build your project against. To see a list of available targets and their corresponding IDs, execute: android list targets .
• path is the location of your project directory.
• name is the name for the project. This is optional—if you're not changing the project name, you don't need this.

Here's an example:

       android update project --name MyApp --target 2 --path ./MyAppProject
      

Setting up a Library Project

A library project is a standard Android project, so you can create a new one in the same way as you would a new application project. Specifically, you can use the android tool to generate a new library project with all of the necessary files and folders.

To create a new library project, navigate to the <sdk>/tools/ directory and use this command:

       android create lib-project --name <your_project_name> \
--target <target_ID> \
--path path/to/your/project \
--package <your_library_package_namespace>
      

The create lib-project command creates a standard project structure that includes preset property that indicates to the build system that the project is a library. It does this by adding this line to the project's project.properties file:

       android.library=true
      

Once the command completes, the library project is created and you can begin moving source code and resources into it, as described in the sections below.

If you want to convert an existing application project to a library project, so that other applications can use it, you can do so by adding a the android.library=true property to the application's project.properties file.

Creating the manifest file

A library project's manifest file must declare all of the shared components that it includes, just as would a standard Android application. For more information, see the documentation for AndroidManifest.xml .

For example, the TicTacToeLib example library project declares the Activity GameActivity :

       <manifest>
  ...
  <application>
    ...
    <activity android:name="GameActivity" />
    ...
  </application>
</manifest>
      

Updating a library project

If you want to update the build properties (build target, location) of the library project, use this command:

       android update lib-project \
--target
       
        <target_ID>
       
       \
--path
       
        path/to/your/project
       
      

Referencing a Library Project

If you are developing an application and want to include the shared code or resources from a library project, you can do so easily by adding a reference to the library project in the application project's build properties.

To add a reference to a library project, navigate to the <sdk>/tools/ directory and use this command:

       android update project \
--target
       
        <target_ID>
       
       \
--path
       
        path/to/your/project
       
       --library
       
        path/to/library_projectA
       
      

This command updates the application project's build properties to include a reference to the library project. Specifically, it adds an android.library.reference. n property to the project's project.properties file. For example:

       android.library.reference.1=path/to/library_projectA
      

If you are adding references to multiple libraries, note that you can set their relative priority (and merge order) by manually editing the project.properties file and adjusting the each reference's . n index as appropriate. For example, assume these references:

       android.library.reference.1=path/to/library_projectA
android.library.reference.2=path/to/library_projectB
android.library.reference.3=path/to/library_projectC
      

You can reorder the references to give highest priority to library_projectC in this way:

       android.library.reference.2=path/to/library_projectA
android.library.reference.3=path/to/library_projectB
android.library.reference.1=path/to/library_projectC
      

Note that the . n index in the references must begin at "1" and increase uniformly without "holes". References appearing in the index after a hole are ignored.

At build time, the libraries are merged with the application one at a time, starting from the lowest priority to the highest. Note that a library cannot itself reference another library and that, at build time, libraries are not merged with each other before being merged with the application.

Declaring library components in the manifest file

In the manifest file of the application project, you must add declarations of all components that the application will use that are imported from a library project. For example, you must declare any <activity> , <service> , <receiver> , <provider> , and so on, as well as <permission> , <uses-library> , and similar elements.

Declarations should reference the library components by their fully-qualified package names, where appropriate.

For example, the TicTacToeMain example application declares the library Activity GameActivity like this:

       <manifest>
  ...
  <application>
    ...
    <activity android:name="com.example.android.tictactoe.library.GameActivity" />
    ...
  </application>
</manifest>
      

For more information about the manifest file, see the documentation for AndroidManifest.xml .

Building a dependent application

To build an application project that depends on one or more library projects, you can use the standard Ant build commands and compile modes, as described in Building and Running . The tools compile and merge all libraries referenced by the application as part of compiling the dependent application project. No additional commands or steps are necessary.