The Android Development Tools (ADT) plugin for Eclipse adds powerful extensions to the Eclipse integrated development environment. It allows you to create and debug Android applications easier and faster. If you use Eclipse, the ADT plugin gives you an incredible boost in developing Android applications:
To begin developing Android applications in the Eclipse IDE with ADT, you first need to download the Eclipse IDE and then download and install the ADT plugin. To do so, follow the steps given in Installing the ADT Plugin, in the installation documentation included with your SDK package.
Once you've installed the ADT plugin, you begin by creating an Android project and then set up a launch configuration. After that, you can write, run, and debug your application.
The sections below provide instructions assuming that you have installed the ADT plugin in your Eclipse environment. If you haven't installed the ADT plugin, you should do that before using the instructions below.
The ADT plugin provides a New Project Wizard that you can use to quickly create an Eclipse project for new or existing code. To create the project, follow these steps:
Enter the project name, the base package name, the name of a single Activity class to create as a stub .java file, and a name to use for your application.
Browse to the directory containing the existing source code and click OK. If the directory contains a valid Android manifest file, the ADT plugin fills in the package, activity, and application names for you.
The ADT plugin creates the these folders and files for you as appropriate for the type of project:
Before you can run and debug your application in Eclipse, you must create a launch configuration for it. A launch configuration specifies the project to launch, the Activity to start, the emulator options to use, and so on.
To create a launch configuration for the application, follow these steps as appropriate for your Eclipse version:
As you begin developing Android applications, you should understand that all Android applications must be digitally signed before the system will install them on the emulator or an actual device.
The ADT plugin helps you get started quickly by signing your .apk files with a debug key, prior to installing them on the emulator. This means that you can compile your application and install it on the emulator without having to generate your own private key. However, please note that if you intend to publish your application, you must sign the application with your own private key, rather than the debug key generated by the SDK tools.
To sign your applications, the ADT plugin requires the Keytool utility included in the JDK. To set up your development environment for signing, you need to make sure that Keytool is available on your machine that the ADT plugin knows how to find it.
In most cases, you can tell the SDK build tools how to find Keytool by making sure that your JAVA_HOME environment variable is set and that it references a suitable JDK. Alternatively, you can add the JDK version of Keytool to your PATH variable.
If you are developing on a version of Linux that originally came with Gnu Compiler for Java, make sure that the system is using the JDK version of Keytool, rather than the gcj version. If keytool is already in your PATH, it might be pointing to a symlink at /usr/bin/keytool. In this case, check the symlink target to make sure that it points to the keytool in the JDK.
In all cases, please read and understand Signing Your Applications, which provides an overview of application signing on Android and what it means to you as an Android application developer.
Once you've set up the project and launch configuration for your application, you can run or debug it as described below.
From the Eclipse main menu, select Run > Run or Run > Debug as appropriate, to run or debug the active launch configuration.Note that the active launch configuration is the one most recently selected in the Run configuration manager. It does not necessarily correspond to the application that is selected in the Eclipse Navigation pane (if any).
To set or change the active launch configuration, use the launch configuration manager. See Creating a Launch Configuration for information about how to access the launch configuration manager..
Running or debugging the application triggers these actions:
You can execute arbitrary code when paused at a breakpoint in Eclipse. For example,
when in a function with a String argument called "zip", you can get
information about packages and call class methods. You can also invoke arbitrary
static methods: for example, entering android.os.Debug.startMethodTracing() will
start dmTrace.
Open a code execution window, select Window>Show View>Display from the main menu to open the Display window, a simple text editor. Type your expression, highlight the text, and click the 'J' icon (or CTRL + SHIFT + D) to run your code. The code runs in the context of the selected thread, which must be stopped at a breakpoint or single-step point. (If you suspend the thread manually, you have to single-step once; this doesn't work if the thread is in Object.wait().)
If you are currently paused on a breakpoint, you can simply highlight and execute a piece of source code by pressing CTRL + SHIFT + D.
You can highlight a block of text within the same scope by pressing ALT +SHIFT + UP ARROW to select larger and larger enclosing blocks, or DOWN ARROW to select smaller blocks.
Here are a few sample inputs and responses in Eclipse using the Display window.
| Input | Response |
|---|---|
zip |
(java.lang.String) /work/device/out/linux-x86-debug/android/app/android_sdk.zip |
zip.endsWith(".zip") |
(boolean) true |
zip.endsWith(".jar") |
(boolean) false |
You can also execute arbitrary code when not debugging by using a scrapbook page. Search the Eclipse documentation for "scrapbook".
Although the recommended way to debug is to use the ADT plugin, you can manually run DDMS and configure Eclipse to debug on port 8700. (Note: Be sure that you have first started DDMS).