JAVA applications in the general, if you need to use reference-based library, usually need to use the following method:

import javax.swing .*;

JAVA expressed above code references the GUI components Swing, javax.swing that JAVA in a package.

android provide some extended JAVA class library, class library is divided into several packages, each package contains a number of categories. For example: In the Android in the calculator is a relatively simple procedure, the entrance program file for the Calculator.java, the file contains the following:

package com.android.calculator2;

import android.app.Activity;

import android.os.Bundle;

import android.util.Log;

import android.util.Config;

import android.view.Menu;

import android.view.MenuItem;

import android.view.Window;

import android.view.View;

import android.widget.Button;

import android.widget.ListView;

import android.content.res.Configuration;

In Android, various android .* packages written in a way, it is important description of the package is as follows:

android.app: to provide high-level process model, provide the basic runtime environment

android.content: contains various data on the device to access and release of class

android.database: browsing through the content provider and operational databases

android.graphics: the underlying graphics library, including canvas, color filters, points, rectangles, you can draw them directly on the screen.

android.location: location and related services in classes

android.media: to provide some class management of multiple audio and video media interface

android.net: network access to help the class, more than the usual java.net .* Interface

android.os: provides a system service, message transport, IPC mechanisms

android.provider: Provides classes to access Android content provider

android.telephony: to provide call-related API interaction

android.view: provide the basis for user interface Interface Framework

android.util: involved in instrumental methods, such as time and date of the operation

android.webkit: default browser operator interface

android.widget: includes a variety of UI elements (mostly visible) in the application use the screen

Article Source: http://os.51cto.com/art/200905/126049.htm

JAVA applications in the general, if you need to use reference-based library, usually need to use the following method:

import javax.swing .*;

JAVA expressed above code references the GUI components Swing, javax.swing that JAVA in a package.

android provide some extended JAVA class library, class library is divided into several packages, each package contains a number of categories. For example: In the Android in the calculator is a relatively simple procedure, the entrance program file for the Calculator.java, the file contains the following:

package com.android.calculator2;

import android.app.Activity;

import android.os.Bundle;

import android.util.Log;

import android.util.Config;

import android.view.Menu;

import android.view.MenuItem;

import android.view.Window;

import android.view.View;

import android.widget.Button;

import android.widget.ListView;

import android.content.res.Configuration;

In Android, various android .* packages written in a way, it is important description of the package is as follows:

android.app: to provide high-level process model, provide the basic runtime environment

android.content: contains various data on the device to access and release of class

android.database: browsing through the content provider and operational databases

android.graphics: the underlying graphics library, including canvas, color filters, points, rectangles, you can draw them directly on the screen.

android.location: location and related services in classes

android.media: to provide some class management of multiple audio and video media interface

android.net: network access to help the class, more than the usual java.net .* Interface

android.os: provides a system service, message transport, IPC mechanisms

android.provider: Provides classes to access Android content provider

android.telephony: to provide call-related API interaction

android.view: provide the basis for user interface Interface Framework

android.util: involved in instrumental methods, such as time and date of the operation

android.webkit: default browser operator interface

android.widget: includes a variety of UI elements (mostly visible) in the application use the screen

Article Source: http://os.51cto.com/art/200905/126049.htm