I'm trying to scrape data from www.apkmirror.com which includes the package name of apps. For example, below
the package name is "com.lenovo.anyshare.gps". I'm considering whether to use the pyparsing expression
Word(alphas + ".")
for the package name, meaning [a-zA-z.] as a regular expression. Is this OK, or would it be too restrictive in some cases? (I wasn't able to find much about restrictions on the package name on https://developer.android.com/studio/build/application-id.html).
Following CommonsWare's comment, I'm assuming for the moment that any character is allowed except a whitespace. (I've updated the regular expression to \S+, since there should be at least one character).
Related
Might there be any issues in having a 2 part package name rather than the prescribed 3 part com.example.appname?
For instance, my app and company name are both named adamsapp. Ie:the package name would be app.adamsapp.
I do not see any documentation from Android or the Play Store that warn against such use of a package name. I'm currently using this convention in both Android Studio and Firebase without any warning or error messages.
According to Android documentation, You can use application id as follows
It must have at least two segments (one or more dots).
Each segment must start with a letter.
All characters must be alphanumeric or an underscore [a-zA-Z0-9_].
This means you can also use 2 part package name like app.adamsapp in your application. There will be no problem except uniqueness. Anyway, due to this issue, you cant use _ as starting of the package name
I want to create apps under my company's name and Android Studio recommends using your domain, eg:
domain: example.com
App: myApp
gives a package name of com.example.myApp
That's all fine, but my company name begins with a number and Android Studio informs me I can't have numbers, eg:
com.1example.myApp
Now I could try "oneexample" and hopefully no-one from oneexample.com starts developing Android apps, but given how many devs appear to have a number at the start of their name, presumably this has come up before. So if I can please ask:
1) How should I tackle naming my packages?
2) Out of curiosity, why can't you have package names beginning with a number?
Thanks heaps!
Quentin.
1) How should I tackle naming my packages?
Short Answer: Android package/subpackage names must begin with an ASCII Latin letter. Since there seems to be no guidance from Google on package naming in cases where domain names begin with a number, developers are left to resolve this themselves.
Here are some real-world examples of domain names starting with a number, and the package names the developers decided to use for Android:
http://www.11bitstudios.com/
https://play.google.com/store/apps/details?id=com.elevenbitstudios.AnomalyWarzoneEarthHD
http://www.23snaps.com/
https://play.google.com/store/apps/details?id=com.snaps23.android
http://www.36you.com/
https://play.google.com/store/apps/details?id=com.thirtysixyougames.google.slotanddragons
Further Background
Java allows package names to begin with an ASCII Latin letter or an underscore character. From Naming a Package (The Java™ Tutorials > Learning the Java Language > Packages):
In some cases, the internet domain name may not be a valid package name. This can occur if the domain name contains a hyphen or other special character, if the package name begins with a digit or other character that is illegal to use as the beginning of a Java name, or if the package name contains a reserved Java keyword, such as "int". In this event, the suggested convention is to add an underscore.
The following examples of "Legalizing Package Names" are also shown:
Domain Name Package Name Prefix
--------------------------- ---------------------------
hyphenated-name.example.org org.example.hyphenated_name
example.int int_.example
123name.example.com com.example._123name
However, Android is more restrictive than Java, and package/subpackage names may NOT begin with an underscore. From Issue 65570 - Android Open Source Project - Issue Tracker - Google Project Hosting:
While Java allows package names that start with underscores, Android application packages (which have additional restrictions) do not. When you try to install an app whose package starts with _, the device PackageManager will reject it. For that reason we tightened the package name validation in Studio when you create the app such that you don't end up creating these packages up front and then suffering later.
Unfortunately, there doesn't seem to be any suggested convention from Google on legalizing package names for domains that begin with a number for Android.
2) Out of curiosity, why can't you have package names beginning with a number?
From Chapter 3. Lexical Structure (The Java® Language Specification - Java SE 7 Edition):
An identifier is an unlimited-length sequence of Java letters and Java digits, the first of which must be a Java letter.
<snip>
The "Java letters" include uppercase and lowercase ASCII Latin letters A-Z (\u0041-\u005a), and a-z (\u0061-\u007a), and, for historical reasons, the ASCII underscore (_, or \u005f) and dollar sign ($, or \u0024). The $ character should be used only in mechanically generated source code or, rarely, to access pre-existing names on legacy systems.
Again, this is further restricted in Android package names. From <manifest> | Android Developers:
package
A full Java-language-style package name for the application. The name should be unique. The name may contain uppercase or lowercase letters ('A' through 'Z'), numbers, and underscores ('_'). However, individual package name parts may only start with letters.
Thanks, #Quentin, for providing info on Android's additional restrictions over Java.
i have a problem in android application package installation,
why android must have two segment of package name,
why i can't use single Name as Package name.
Now:"com.alert.myalert"
Need:"myalert", in my application i required when my app is installed in device, it shows only my app name, when the user have to check in Settings->App->myalert. This is my problem, i can't get that now showing Settings->App->com.alert.myalert. kindly help me, Thanks in Advance.
You have an explanation about this here, it's just a convention to keep the names of your packages like the reverse of your domain.
From SUN Convention:
The prefix of a unique package name is always written in all-lowercase
ASCII letters and should be one of the top-level domain names,
currently com, edu, gov, mil, net, org, or one of the English
two-letter codes identifying countries as specified in ISO Standard
3166, 1981.
Subsequent components of the package name vary according to an
organization's own internal naming conventions. Such conventions might
specify that certain directory name components be division,
department, project, machine, or login names.
I hope to rename a package name under the folder \src , I see the following warning.
By convention, the package names usually start with a lowercase letter
Will I meet trouble if I rename a package with uppercase letter?
Just because it's an acronym doesn't mean you should capitalize it in your package name. Class naming convention recommends making only the first letter in acronym-ish name portions upper-case, although for historical reasons there are classes that don't follow that convention.
The bottom line is that as long as it's a legal name, you're fine from the Java side of things.
Mixed-case directories sometimes cause issues across OSes, particularly combined with version control. For practical reasons alone it might be worth following convention.
For the "Hello World" example in android.com, the package name is
"package com.example.helloandroid;"
Is there any guideline/standard to name this package? (references would be nice)
Android follows normal java package conventions plus here is an important snippet of text to read (this is important regarding the wide use of xml files while developing on android).
The reason for having it in reverse order is to do with the layout on the storage media. If you consider each period ('.') in the application name as a path separator, all applications from a publisher would sit together in the path hierarchy.
So, for instance, packages from Adobe would be of the form:
com.adobe.reader (Adobe Reader)
com.adobe.photoshop (Adobe Photoshop)
com.adobe.ideas (Adobe Ideas)
[Note that this is just an illustration and these may not be the exact package names.]
These could internally be mapped (respectively) to:
com/adobe/reader
com/adobe/photoshop
com/adobe/ideas
The concept comes from Package Naming Conventions in Java, more about which can be read
here:*
http://en.wikipedia.org/wiki/Java_package#Package_naming_conventions
Source: http://www.quora.com/Why-do-a-majority-of-Android-package-names-begin-with-com
The package name is used for unique identification for your application.
Android uses the package name to determine if the application has been installed or not.
The general naming is:
com.companyname.applicationname
eg:
com.android.Camera
http://docs.oracle.com/javase/tutorial/java/package/namingpkgs.html
Companies use their reversed Internet domain name to begin their
package names—for example, com.example.mypackage for a package named
mypackage created by a programmer at example.com.
Name collisions that occur within a single company need to be handled
by convention within that company, perhaps by including the region or
the project name after the company name (for example,
com.example.region.mypackage).
If you have a company domain www.example.com
Then you should use:
com.example.region.projectname
If you own a domain name like example.co.uk than it should be:
uk.co.example.region.projectname
If you do not own a domain, you should then use your email address:
for name#example.com it should be:
com.example.name.region.projectname
com = commercial application (just like .com, most people register their app as a com app)
First level = always the publishing entity's' name
Second level (optional) = sub-division, group, or project name
Final level = product name
For example the android launcher (home screen) is
com.google.android.launcher
Generally the first 2 package "words" are your web address in reverse. (You'd have 3 here as convention, if you had a subdomain.)
So something stackoverflow produces would likely be in package com.stackoverflow.whatever.customname
something asp.net produces might be called
net.asp.whatever.customname.omg.srsly
something from mysubdomain.toplevel.com would be
com.toplevel.mysubdomain.whatever
Beyond that simple convention, the sky's the limit. This is an old linux convention for something that I cannot recall exactly...
From the Kotlin Android style guide:
Package names are all lowercase, with consecutive words simply
concatenated together (no underscores).
https://developer.android.com/kotlin/style-guide#package_names
But if your Android App is only for personal purpose or created by you alone, you can use:
me.app_name.app