32.What are the features of Android?
Components can be reused and replaced by the application framework.
Optimized DVM for mobile devices
SQLite enables to store the data in a structured manner.
Supports GSM telephone and Bluetooth, WiFi, 3G and EDGE technologies
The development is a combination of a device emulator, debugging tools, memory profiling and plug-in for Eclipse IDE.
33.What are Ping and Tracert?
Ping: Ping is used for verification of IP-Level connectivity. The following are the processes for using ping:
1. To ping the loopback address type ping 127.0.01
2. To ping the IP address of a local computer system to verify whether it is correctly verified or not – ping ipaddress of local host. Ex: c:\>pint 129.29.3.12
3. To ping the IP address of the gateway that is default for verifying the functionality of the gate way = ping ipaddress of default gateway.
Tracert: A route-tracing utility that is used for determining the path of a network from source to destination. The determination of the path that a packet takes on the network tracert is used.
34.Describe Android Application Architecture.
Android Application Architecture has the following components:
Services – like Network Operation
Intent - To perform inter-communication between activities or services
Resource Externalization - such as strings and graphics
Notification signaling users - light, sound, icon, notification, dialog etc.
Content Providers - They share data between applications
35.What are the advantages of Android?
The following are the advantages of Android:
The customer will be benefited from wide range of mobile applications to choose, since the monopoly of wireless carriers like AT&T and Orange will be broken by Google Android.
Features like weather details, live RSS feeds, opening screen, icon on the opening screen can be customized
Innovative products like the location-aware services, location of a nearby convenience store etc., are some of the additive facilities in Android.
36.What are the steps that are involved in converting the android in newer version?
To release a new version requires lots of changes and a process has to be developed to build the changes. The steps that is required:
• In the beginning of the creation the software gets the built or the earlier version of the system image. This includes various certifications and deployment rules and regulations.
• The built goes through operator testing and this is one of the important phase as it allows lot of bugs to be found and corrected.
• The release then goes the regulators, moderators and operators to produce the devices to release the source code. The code that is written is checked for errors and there is a sign of the agreement that take place between the contributors and some verification are performed.
• The production of the software begins and the release process starts and then the release will allow the users to grab the devices.
37. What is the role of compatibility that is used in Android?
The compatibility is defined in terms of android compatible devices that run any application. This application is written by third party developers using the Android platform that comes in the form of SDK and NDK. There are many filters that are used to separate devices that are there to participate in the compatibility mode for the Android applications. The devices that are compatible require the android to approve it for their trademark. The devices that are not passes the compatibility are just given in the Android source code and can use the android trademark. The compatibility is a way through which the user can participate in the Android application platform. The source code is free to use and it can be used by anyone
38. What are the different forms of communication provided by the Android applications?
There are different forms of communication that is used by the Android application developers like:
• Internet telephony: this is used to add SIP-based features to the application. This includes the full SIP protocol stack and includes integrated call management services. These services allow setting the ongoing and incoming voice calls without managing the sessions at the transport level. This provides the communication to be successful by determining the associated carriers.
• NFC (Near field communications) - this is used to allow the communication to happen between the developers that create the new class of application. These new applications are created and provided as a service to the users, organizations, merchants and advertisers. It allows the tagging of application that interests the user. The tag allows the user to communicate through wireless telephony services and allow the use of device hardware.
39. What are the multimedia features involved in making Android popular?
There is the demand for the rich multimedia that involves many features that are used till now to make the Android market more popular in all the phases. The application includes the following:
• Mixable audio effects – developer can easily create audio environments using the API key that is provided with it like creating equalization, bass boost, headphone feature, etc. The android provide the tools that can be used to mix the audio effects and apply it.
• There is also support for new media formats like VP8 open video compression format that uses a container format that can run on all the platforms and add the support for AAC and AMR encoding. The applications provided allow higher quality video to be captured.
• The application allows the access to multiple cameras that allows the use of APIs to include the camera and its properties in one. The platform provides the application to include the camera with high and low resolution.
40. What are the services that can be allowed to run in a single process?
Android allows all the services and applications to run on a single process. This behavior is the default behavior that can be changed by using the different settings and functions. The process can be declared by using android: process attribute. This places the component explicitly on the process. Service is not a separate process and itself it’s a process if not defined separately. The service is not used as a thread as well but it defines other threads in the program to do the work and create the application. The application runs and finds the errors in the program and the service just takes the necessary actions on them. The service also responds to the errors whenever necessary.
41. What are the steps that are required in Service Lifecycle?
The services allow the proper functioning of the system.
• The service starts with Context.startService() function and the system will retrieve the service using onCreate() method. To start the service it calls on onStartCommand(Intent, int, int)method with proper arguments that are given by the client.
• If the service is running and due to some problem the user doesn't want to run it then it uses Context.stopService()or stopSelf() method to properly implement the service for the user.
• Due to multiple calls of the Context.startService() method the program doesn't do any nesting of the program and shows the stopping of the services.
• Services can use the command stopSelf(int)method to stop their own service. A service doesn't stop untill all the processes are processed.
42. What are the different modes of operations used in services for Android?
There are two modes of operations that are necessary to run depending on the value returned by the startcommand(). The modes are as follows:
• START_STICKY: this mode is used for the services that are explicitly started and stopped according to the need and the requirement of the user.
• START_NOT_STICKY or START_REDELIEVER_INTENT: this service mode is used for services that are running only when the processing command sent to them. That means these run on the basis of the command that is passed to them by giving the instruction of execution.
• Clients uses the Context.bindService() that is used to get the persistent connection for a service. To create a service that is not already running the command onCreate is used.
43. What is the main reason of using process lifecycle in Android?
The android system will keep all the process that are hosting the services together at one place till the time the service is not started or connected to the client. The priority of the process is divided when running low on memory or when the process has to be killed. The process lifecycle is as follows:
• The service is running currently then the methods onCreate(), onStartCommand(), and onDestroy()methods, will run in the foreground to execute the process without being killed.
• The service is already started then the process can be considered as less important then the processes that are currently visible and used. This is done as there are only few processes that are visible to the users on the screen.
• The clients are bounded to the services they are providing requires more priority in the execution list.
• The service that is started uses startForeground(int, Notification)API to allow all the services to run in the foreground state. The system considers only the services where the user is still active as the services not to be killed.
44. How all the activities that are running run in main thread?
All the applications that are running or can be accessed runs in main thread of user interface by default. The modification can be done to make it run differently or to make it run or not at all. The exception also comes defining that the code handles the IPC calls that are coming from other processes. The system used to maintain separate pools for all the processes and threads. One pool consists of the transaction threads that are in each process to dispatch all the incoming calls. It also allows the interpersonal calls to be handled in a specialized manner. This allows the creation of separate threads that is used for long-running code, and to avoid blocking of the main user interface threads. The services that run can be killed by the system if it is going out of memory. The system restart the service and implement onStartCommand() to bring the activities back in the memory pool?
