Android  U 网页代码：/ - OpenGrok cross reference for / (aospxref.com)

字段参数介绍

实体对象 ApnSetting

ApnSetting.java - OpenGrok cross reference for /frameworks/base/telephony/java/android/telephony/data/ApnSetting.java (aospxref.com)

An Access Point Name (APN) configuration for a carrier data connection.

一个运营商数据连接的接入点名称（APN）配置。

界面Projection

ApnEditor.java - OpenGrok cross reference for /packages/apps/Settings/src/com/android/settings/network/apn/ApnEditor.java (aospxref.com)

客制化开发举例：sourceType字段标记APN来源（预置、服务器下发或用户添加 ）

源码实现：ApnEditor.java - OpenGrok cross reference for /packages/apps/Settings/src/com/android/settings/network/apn/ApnEditor.java (aospxref.com)

private static final int SOURCE_TYPE_INDEX = 26;//自定义新增数据库字段索引号

// the source type for apn
public static final int SOURCE_TYPE_DEFAULT = 0; // the default configured by apns-config.xml
public static final int SOURCE_TYPE_USER_EDIT = 1; // from user editing

private int mSourceType = SOURCE_TYPE_DEFAULT;//初始化默认为预置类型

/**
 * Standard projection for the interesting columns of a normal note.
 */
private static final String[] sProjection = new String[] {
        Telephony.Carriers._ID,     // 0
        Telephony.Carriers.NAME,    // 1
        Telephony.Carriers.APN,     // 2
        Telephony.Carriers.PROXY,   // 3
        Telephony.Carriers.PORT,    // 4
        Telephony.Carriers.USER,    // 5
        Telephony.Carriers.SERVER,  // 6
        Telephony.Carriers.PASSWORD, // 7
        Telephony.Carriers.MMSC, // 8
        Telephony.Carriers.MCC, // 9
        Telephony.Carriers.MNC, // 10
        Telephony.Carriers.NUMERIC, // 11
        Telephony.Carriers.MMSPROXY, // 12
        Telephony.Carriers.MMSPORT, // 13
        Telephony.Carriers.AUTH_TYPE, // 14
        Telephony.Carriers.TYPE, // 15
        Telephony.Carriers.PROTOCOL, // 16
        Telephony.Carriers.CARRIER_ENABLED, // 17
        Telephony.Carriers.BEARER, // 18
        Telephony.Carriers.BEARER_BITMASK, // 19
        Telephony.Carriers.ROAMING_PROTOCOL, // 20
        Telephony.Carriers.MVNO_TYPE,   // 21
        Telephony.Carriers.MVNO_MATCH_DATA,  // 22
        Telephony.Carriers.EDITED_STATUS,   // 23
        Telephony.Carriers.USER_EDITABLE,   // 24
        Telephony.Carriers.CARRIER_ID,       // 25
        SOURCE_TYPE    //自定义新增字段，MTK inner suppport
};

void fillUI(boolean firstTime) {
    //从数据库更新APN来源类型
    mSourceType = mApnData.getInteger(SOURCE_TYPE_INDEX);
}

telephony.db字段

开机Android TelephonyProvider会将apns-conf.xml APN配置信息 load到数据库telephony.db名为carrier的表中，可以用SQLite工具可视化。

手机存储目录：data/user_de/0/com.android.providers.telephony，在子文件夹databases

RecNo	FieldName	SQLType	DefaultValue	备注
1	_id	INTEGER
2	name	TEXT	''	必须
3	numeric	TEXT	''	=mcc+mnc
4	mcc	TEXT	''	必须
5	mnc	TEXT	''	必须
6	class	TEXT	''	运营商需求
7	apn_source	INTEGER	-1
8	modify_apn_name_id	INTEGER	-1
9	carrier_id	INTEGER	-1
10	apn	TEXT	''	必须
11	user	TEXT	''
12	server	TEXT	''
13	password	TEXT	''
14	proxy	TEXT	''
15	port	TEXT	''
16	mmsproxy	TEXT	''
17	mmsport	TEXT	''
18	mmsc	TEXT	''
19	authtype	INTEGER	-1
20	type	TEXT	''
21	current	INTEGER
22	sourcetype	INTEGER	0
23	protocol	TEXT	IP
24	roaming_protocol	TEXT	IP
25	carrier_enabled	BOOLEAN	1
26	bearer	INTEGER	0
27	bearer_bitmask	INTEGER	0
28	network_type_bitmask	INTEGER	0
29	lingering_network_type_bitmask	INTEGER	0
30	mvno_type	TEXT	''
31	mvno_match_data	TEXT	''
32	sub_id	INTEGER	-1	指明归属的卡，来源subscription
33	profile_id	INTEGER	0
34	modem_cognitive	BOOLEAN	0
35	max_conns	INTEGER	0
36	wait_time	INTEGER	0
37	max_conns_time	INTEGER	0
38	mtu	INTEGER	0
39	mtu_v4	INTEGER	0
40	mtu_v6	INTEGER	0
41	edited	INTEGER	0
42	user_visible	BOOLEAN	1
43	user_editable	BOOLEAN	1
44	owned_by	INTEGER	1	APN归属者，0或1，基本都是1.
45	apn_set_id	INTEGER	0	APN类型集合的id，功能基本都没用到
46	skip_464xlat	INTEGER	-1	464xLAT上层有个开关会设置下去给MD，默认是开的。 参考NetworkAgentConfig.java 介绍： Set to skip 464xlat. This means the device will treat the network as IPv6-only and will not attempt to detect a NAT64 via RFC 7050 DNS lookups.
47	always_on	INTEGER	0

相关默认值

在MMS模块有定义proxy port默认值是80（在APN没有配置的情况下），代码实现如下：

ApnSettings.java - OpenGrok cross reference for /packages/services/Mms/src/com/android/mms/service/ApnSettings.java (aospxref.com)

private static ApnSettings getApnSettingsFromCursor(Cursor cursor, String requestId)
        throws ApnException {
    // Default proxy port to 80
    int proxyPort = 80;
    //...
    if (!TextUtils.isEmpty(proxyAddress)) {
         proxyAddress = Inet4AddressUtils.trimAddressZeros(proxyAddress);
         final String portString =
                 trimWithNullCheck(cursor.getString(COLUMN_MMSPORT));
         if (!TextUtils.isEmpty(portString)) {
             try {
                 proxyPort = Integer.parseInt(portString);
             } catch (NumberFormatException e) {
                 LogUtil.e(requestId, "Invalid port " + portString + ", use 80");
             }
         }
     }
     return new ApnSettings(
             mmscUrl, proxyAddress, proxyPort, getDebugText(cursor));
}