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This set of libraries provides APIs for essential app architecture tasks like lifecycle management and data persistence, so you can write modular apps with less boilerplate code.

Learn more. The Android Support Library offers backward-compatible versions of a number of features, including others not built into the framework. The Data Binding Library enables you to write declarative layouts. Android Test helps you build and run test code for your app. The Google Play Billing Library provides a simple interface for sending billing requests and managing billing transactions with Google Play.

You can install and run your app on the Android Emulator faster than with a physical device. It simulates various device configurations and hardware sensors, and it uses a snapshot to quickly resume exactly where you left off. Alternatively you can download the source tree and link it up with your IDE. Stack Overflow for Teams — Collaborate and share knowledge with a private group.

Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. Android Developer Documentation: download? Ask Question. Asked 8 years, 8 months ago. Active 1 year, 1 month ago. Viewed 21k times. Android Auto Bulletin. Android 12 documentation Android 12 is available!

This site includes documentation for implementing the features, improvements, and enhancements in the newest version of Android. Read the docs. September Security Bulletins We've published the September Android and Pixel Bulletins with links to associated fixes and new build numbers to support the September security release. Build fingerprint The build fingerprint is a unique, human-readable string containing manufacturer information issued to each build that is useful in reporting issues and now documented more fully.

The first two lines in the list are emulators, and the third line is a hardware device that is attached to the computer. The adb devices command has a corner-case command sequence that causes running emulator s to not show up in the adb devices output even though the emulator s are visible on your desktop.

This happens when all of the following conditions are true:. One way to avoid this situation is to let the emulator choose its own ports, and don't run more than 16 emulators at once. Another way is to always start the adb server before you use the emulator command, as explained in the following examples. Example 1: In the following command sequence, the adb devices command starts the adb server, but the list of devices does not appear. Stop the adb server and enter the following commands in the order shown.

For the avd name, provide a valid avd name from your system. To get a list of avd names, type emulator -list-avds. Example 2: In the following command sequence, adb devices displays the list of devices because the adb server was started first. To see the emulator in the adb devices output, stop the adb server, and then start it again after using the emulator command and before using the adb devices command, as follows:.

For more information about emulator command-line options, see Using Command Line Parameters. If multiple devices are running, you must specify the target device when you issue the adb command. To specify the target, use the devices command to get the serial number of the target. Once you have the serial number, use the -s option with the adb commands to specify the serial number. In the following example, the list of attached devices is obtained, and then the serial number of one of the devices is used to install the helloWorld.

Note: If you issue a command without specifying a target device when multiple devices are available, adb generates an error. If you have multiple devices available, but only one is an emulator, use the -e option to send commands to the emulator. Likewise, if there are multiple devices but only one hardware device attached, use the -d option to send commands to the hardware device.

You can use adb to install an APK on an emulator or connected device with the install command:. You must use the -t option with the install command when you install a test APK. For more information, see -t. Instead, Android Studio handles the packaging and installation of the app for you.

You can use the forward command to set up arbitrary port forwarding, which forwards requests on a specific host port to a different port on a device. The following example sets up forwarding of host port to device port Use the pull and push commands to copy files to and from an device.

Unlike the install command, which only copies an APK file to a specific location, the pull and push commands let you copy arbitrary directories and files to any location in a device. In some cases, you might need to terminate the adb server process and then restart it to resolve the problem e. To stop the adb server, use the adb kill-server command. You can then restart the server by issuing any other adb command. You can issue adb commands from a command line on your development machine or from a script.

The usage is:. If there's only one emulator running or only one device connected, the adb command is sent to that device by default. You can use the shell command to issue device commands through adb, or to start an interactive shell.

To issue a single command use the shell command like this:. To start an interactive shell on a device use the shell command like this:. Note: With Android Platform-Tools 23 and higher, adb handles arguments the same way that the ssh 1 command does. But, this change means that the interpretation of any command that contains shell metacharacters has also changed. For example, the adb shell setprop foo 'a b' command is now an error because the single quotes ' are swallowed by the local shell, and the device sees adb shell setprop foo a b.

To make the command work, quote twice, once for the local shell and once for the remote shell, the same as you do with ssh 1. For example, adb shell setprop foo "'a b'". Android provides most of the usual Unix command-line tools.

For a list of available tools, use the following command:. Help is available for most of the commands via the --help argument. Many of the shell commands are provided by toybox. General help applicable to all toybox commands is available via toybox --help. See also Logcat Command-Line Tool which is useful for monitoring the system log. Within an adb shell, you can issue commands with the activity manager am tool to perform various system actions, such as start an activity, force-stop a process, broadcast an intent, modify the device screen properties, and more.

While in a shell, the syntax is:. You can also issue an activity manager command directly from adb without entering a remote shell. See the Specification for intent arguments. Options are: -D : Enable debugging. Prior to each repeat, the top activity will be finished.

This command kills only processes that are safe to kill and that will not impact the user experience.