方法一（从应用层设置）:

 private int CreateRasEntry(String sAPN)
 {
  int id = 0;
  ContentResolver contentResolver = getContentResolver();
  ContentValues values = new ContentValues();
  values.put("name", "中国联通");
  values.put("apn", "cmnet");
  values.put("numeric", "46000");
  values.put("mcc", "460");
  values.put("mnc", "00");
  values.put("proxy", "10.0.0.172");
  values.put("port", "80");
  values.put("mmsc", "http://moternet.com.cn/");
  values.put("current", 1);


  Cursor cursor = null;
  try
  {
   Uri uri = Uri.parse("content://telephony/carriers");
   cursor = contentResolver.query(uri, new String[]{"current","_id"}, "apn=\'" + sAPN + "\'", null, null);
   if(cursor!=null && cursor.getCount()>0)
   {
    cursor.moveToFirst();
    id = cursor.getInt(cursor.getColumnIndex("_id"));
    if(cursor.getInt(cursor.getColumnIndex("current"))!=1)
    {
     contentResolver.update(uri, values, "_id=="+id, null);
    }

    uri = Uri.parse("content://telephony/carriers/preferapn");   
    ContentResolver resolver = getContentResolver();  
    values = new ContentValues();  
    values.put("apn_id", id);  
    resolver.update(uri, values, null, null); 
   }
   else
   {
    if(cursor!=null) cursor.close();
 
    Uri newRow = contentResolver.insert(uri, values);
    if (newRow != null)
    {
     cursor = contentResolver.query(newRow, null, null, null, null);
     cursor.moveToFirst();
     id = cursor.getInt(cursor.getColumnIndex("_id"));//取得新创建的接入点的id
 
     uri = Uri.parse("content://telephony/carriers/preferapn");   
     ContentResolver resolver = getContentResolver();  
     values = new ContentValues();  
     values.put("apn_id", id);  
     resolver.update(uri, values, null, null); 
    }
   }
  }
  catch (Exception e)
  {
   e.printStackTrace();
  }
 
  if (cursor != null)
   cursor.close();
  return id;
 }  

<uses-permission android:name="android.permission.WRITE_APN_SETTINGS" /><!-- 设置APN权限 --> 

方法二（从系统层设置）: 

find -name apns-conf.xml
在apns-conf.xml中添加以下配置：

<apn carrier="中国联通"
      mcc="460"
      mnc="06"
      apn="cmnet"
      type="default,supl,net,xcap"
      protocol="IPV4V6"
      roaming_protocol="IPV4V6"
  />