android APN code关键点

Users can go to Settings-->Wireless control-->Mobile networks-->Access point names to view and edit existing APNs.

Google Android uses a SQLite data table to store all APNs configured on the device, as shown below:

Database: /data/data/com.android.providers.telephony/databases/telephony.db

Table: carriers

URI: content://telephony/carriers

frameworks/base/core/res/res/xml/apns.xml // Android自带的内部APN配置文件

system/etc/apns-conf.xml // 第三方提供的APN配置

在编译该product时会将device/generic/goldfish/data/etc/apns-conf.xml文件拷贝到system/etc/目录下，最后打包到system.img中。

packages/providers/TelephonyProvider/src/com/android/providers/telephony/TelephonyProvider.java // 初始化操作

com.android.providers.telephony.TelephonyProvider.DatabaseHelper.onCreate(SQLiteDatabase) // 创建数据表carriers，用来保存apn配置信息

com.android.providers.telephony.TelephonyProvider.DatabaseHelper.initDatabase(SQLiteDatabase) // 从指定路径读取apn配置文件

com.android.providers.telephony.TelephonyProvider.DatabaseHelper.loadApns(SQLiteDatabase, XmlPullParser) // Loads apns from xml file into the database

settings中对apn的操作：

packages/apps/Settings/src/com/android/settings/ApnEditor.java

packages/apps/Settings/src/com/android/settings/ApnPreference.java

packages/apps/Settings/src/com/android/settings/ApnSettings.java

参考：

Managing APN Settings on Google Android
[title2]Android APN配置[/title2]