I've seen all the work you guys here at XDA developer do (and it's all really great).
And i'd really like to be able to develop stuff for android devices like you guys!
I know how to use Eclipse to develop apps and i've made a few apps already (no games or any real good stuff because i'm still learning right now).
But I want to be able to develop ROMs,kernels,...etc.U know!!
I've signed up for a java coarse at "New Horizons" training center and i'm gonna start in about a month.
But that won't teach me everything,it won't even teach me everything about application-creating
So,here I am,asking you guys (android developers):
How can I learn the stuff that you've learned?
What websites should I check out?
Where and how can I learn how to develop complete apps,games,Roms and kernels for any android smartphone?
In other words;Tell me how you learned all this stuff,and how can I learn it too?
Thank U!!!
Custom ROMS are not created from scratch.
Existing ROMs from the manufactors are taken appart, dissected, modified and packed again to be uploaded here.
The best way to start on that is just by taking apart existing ROMs and looking through the files.
Modifiy some, repack them and check if it still works.
Repeat said process .
If you want to go deeper read up about decompiling & recompiling apk files.
Modifying bak smali code.
For creating your own kernels, just use google, so much info about that. Its not an android only topic, but a linux topic and the internet has plenty of info on that.
Good luck on your journy .
The first thing you have to do is to understand the system. This means you have to understand Linux, the kernel, the datasystem(because Android is obvisiously based on Linux).
You have to be able to understand written code or program/code yourself.
The best way to code for android is to learn java.
Read this here: http://developer.android.com/guide/index.html
Ok,thanks for the information.
But let me tell you what I already know and understand:
Android is Linux,I know what linux is,I know everything about it and i'm already using GNU Fedora and Ubuntu (I have spent countless hours reading the "about Ubuntu" and "about GNU"),In Android or Linux everything is a file and everything in the system or the apps has a file .
Now I have some questions that I need you to answer first before adding anything else:
1-Is learning Java enough?don't I need to learn any other programing languages?And if I do,then what languages will I need to learn?
2-how can I learn to build or modify an android kernel (linux)?give me a good site or something?
3-how can i learn to decompile and recompile apks and roms?
4-What will I be needing to learn in order to buid a kernel?
5-What programing langusge is the android source code written in?I think it's java,am I right?
I hope you answer these questions before adding anymore information.
Thanks in advance,and I hope it's not any trouble)
1-No, you need to compile and modify kernels etc. therefore you need to program in C(I guess)
2- Well, buy books about Linux and Kernels etc. Its quite difficult to teach it. You gotta learn yourself.
3- Decompiling and recompiling is not an option. Its like stealing - Dont modify apks without permission. If you got permission then you modify apks with the SDK(Java).
Roms are often compiled in C(I think)
4 - Books and the will to learn.
5. Android Source Code is C(like Linux), Android Apps are Java.
Quinity said:
1-No, you need to compile and modify kernels etc. therefore you need to program in C#(I guess)
2- Well, buy books about Linux and Kernels etc. Its quite difficult to teach it. You gotta learn yourself.
3- Decompiling and recompiling is not an option. Its like stealing - Dont modify apks without permission. If you got permission then you modify apks with the SDK(Java).
Roms are often compiled in C#(I think)
4 - Books and the will to learn.
5. Android Source Code is C#(like Linux), Android Apps are Java.
Click to expand...
Click to collapse
Just making sure you mean c, not c# right??
Try visiting the android website. There is a tutorial on how to get started with android development.
There is a fee that you would need to pay per year in order for your application to appear on the android market where you will be able to sell your product.
Java will be advantageous when it comes to android programming and if you know J2ME that will be a bonus as well.
ps:Learn from examples, buy a good book for beginners: “Hello, Android” and “Beginning Android“.
(i’m not a developer)
Nilurun said:
There is a fee that you would need to pay per year in order for your application to appear on the android market where you will be able to sell your product.
Click to expand...
Click to collapse
I believe it is a one time fee when you sign up, not a yearly fee.
Ok,I'm already using the Android developer website,but the whole thing takes time to read all the guidelines and do tutorials and packages.
So all i'm asking here:
What programming languages do I need to learn in order to be able to understand the native android source code and develop everything starting from kernel down to apps,I already know that I need to learn Java for apps and thanks to "Quinity" I know I need to learn C to understand the native source code.
I can easily learn C at any professional training center.The questions now are:
1-how and where can I learn to edit the Linux kernel and decompile and recompile ROM and APK files?
2-why do I even need to learn Java ME (formerly J2ME)?
I understand that Java ME is the java environment originally running on small devices with limited processors and performance such as mobile phones and smart phones,but what is the use of it when it comes to the app development,or any Android development at all?
And thanks for all the replies.
One more thing,I have to make sure what the android source code written in.And Quick answers;PLEASE.
Is it C,or C#?
C
Check out the wikipedia article, which states at the beginning:
The Android open-source software stack consists of Java applications running on a Java-based, object-oriented application framework on top of Java core libraries running on a Dalvik virtual machine featuring JIT compilation. Libraries written in C include the surface manager, OpenCore[21] media framework, SQLite relational database management system, OpenGL ES 2.0 3D graphics API, WebKit layout engine, SGL graphics engine, SSL, and Bionic libc.
Dark3n said:
C
Check out the wikipedia article, which states at the beginning:
The Android open-source software stack consists of Java applications running on a Java-based, object-oriented application framework on top of Java core libraries running on a Dalvik virtual machine featuring JIT compilation. Libraries written in C include the surface manager, OpenCore[21] media framework, SQLite relational database management system, OpenGL ES 2.0 3D graphics API, WebKit layout engine, SGL graphics engine, SSL, and Bionic libc.
Click to expand...
Click to collapse
Thanks,the article really did help a lot.
So,now I need to learn Java SE (without question),but what about Java EE and Java ME,will they be useful in the app development process,will I need them?
And what If I can't learn C (it's extremely hard to find a training center that teaches C these days),will learning C++ or C# do me any good?
I know that the source code is written in C,but is it really a big difference between the three,If I learn C# or C++ will I still be able to do everything I need to do and fully understand the code?
note that i'm on a tight schedule for now and I need to learn only the stuff I can't do without.
speeed_demon47 said:
Thanks,the article really did help a lot.
So,now I need to learn Java SE (without question),but what about Java EE and Java ME,will they be useful in the app development process,will I need them?
And what If I can't learn C (it's extremely hard to find a training center that teaches C these days),will learning C++ or C# do me any good?
I know that the source code is written in C,but is it really a big difference between the three,If I learn C# or C++ will I still be able to do everything I need to do and fully understand the code?
note that i'm on a tight schedule for now and I need to learn only the stuff I can't do without.
Click to expand...
Click to collapse
I think you are missunderstanding something here.
You should start by just learning java, the different EE ME SE etc. are still java.
The difference is that those are sets of java platforms. They bring, as does the android platform, prebuild libaries along, these contain functions (i.e. print that, create datastructure X) so you don't have to write every tiny bit of code.
Forget about those.
You want to use java on the android platform, which still uses java, but brings along its own libaries with prebuild code you can use ( See http://developer.android.com/reference/packages.html ).
So just learn java, if you want to work with android you can learn java on the android platform, this way you will already be familiar with the libaries provided by android.
I would say C# is more similar to java and C++ is more similar to C.
I don't understand what you mean with "do everything i need to do".
What do you need to do?
"Understand code".
Understanding code does require more than knowing what each line does, you will have to see the bigger picture ,not just few lines of code, to understand what is does. Depending on how the code is written (tidy or confusing), is the code commented? It might take ages to understand it.
Programming is sometimes a bit like art . Code can be beautiful or horrible
You don't have to do everything in a training center either.
The internet, time and interest is enough. There are so many tutorials and pages available...
You could have also found most of the answers by just using google...
Wikipedia article about java holds the information about the differences between EE/ME/SE etc...
Searching for terms like "difference C C sharp" etc. holds the answer to that question...
So maybe a training center is better for you to learn those programming languages, as "google skills" will certainly be required to teach you those things yourself.
What tight schedule are you on?
Dark3n said:
I think you are missunderstanding something here.
You should start by just learning java, the different EE ME SE etc. are still java.
The difference is that those are sets of java platforms. They bring, as does the android platform, prebuild libaries along, these contain functions (i.e. print that, create datastructure X) so you don't have to write every tiny bit of code.
Forget about those.
You want to use java on the android platform, which still uses java, but brings along its own libaries with prebuild code you can use ( See http://developer.android.com/reference/packages.html ).
So just learn java, if you want to work with android you can learn java on the android platform, this way you will already be familiar with the libaries provided by android.
I would say C# is more similar to java and C++ is more similar to C.
I don't understand what you mean with "do everything i need to do".
What do you need to do?
"Understand code".
Understanding code does require more than knowing what each line does, you will have to see the bigger picture ,not just few lines of code, to understand what is does. Depending on how the code is written (tidy or confusing), is the code commented? It might take ages to understand it.
Programming is sometimes a bit like art . Code can be beautiful or horrible
You don't have to do everything in a training center either.
The internet, time and interest is enough. There are so many tutorials and pages available...
You could have also found most of the answers by just using google...
Wikipedia article about java holds the information about the differences between EE/ME/SE etc...
Searching for terms like "difference C C sharp" etc. holds the answer to that question...
So maybe a training center is better for you to learn those programming languages, as "google skills" will certainly be required to teach you those things yourself.
What tight schedule are you on?
Click to expand...
Click to collapse
Yes,I already know all about java,I read the articles on wikipedia,but why would I need to learn java enterprise? Isn't it mostly used around internet applications and servers? Can't I just use the APIs if i'm going to build an app that needs internet or server connectivity?
And why would I need to learn java Micro? Doesn't android use dalvik virtual machine to run apps? I mean,java Micro is mostly used to create feature phone apps,why would I need it with android?
There's something I don't understand though,on wikipedia the article about android says this:"Applications are usually developed in the Java language using the Android Software Development Kit, but other development tools are available, including a Native Development Kit for applications or extensions in C or C++"
So,the question is;what is the difference between apps developed in java and apps developed in C or C++?
The problem about C# is that I don't know anything about it;can't find any articles on wikipedia and other sites really don't help!!!
I meant by "understanding the code",having the ability to understand the command lines,what they do,what each line is responsible for and having the ability to edit or adjust something,.....etc.
And for the tight schedule;I need to learn everything about android within 6 months (I don't need to learn C as much,but it'd be a bonus),and that's why I go to training centers,faster and more efficient than self learning.
What did u mean by "google skills"?
And what did u mean by "learn java on the android platform"?
Thanks for the help and providing quick answers.
speeed_demon47 said:
Yes,I already know all about java,I read the articles on wikipedia,but why would I need to learn java enterprise? Isn't it mostly used around internet applications and servers? Can't I just use the APIs if i'm going to build an app that needs internet or server connectivity?
And why would I need to learn java Micro? Doesn't android use dalvik virtual machine to run apps? I mean,java Micro is mostly used to create feature phone apps,why would I need it with android?
There's something I don't understand though,on wikipedia the article about android says this:"Applications are usually developed in the Java language using the Android Software Development Kit, but other development tools are available, including a Native Development Kit for applications or extensions in C or C++"
So,the question is;what is the difference between apps developed in java and apps developed in C or C++?
The problem about C# is that I don't know anything about it;can't find any articles on wikipedia and other sites really don't help!!!
I meant by "understanding the code",having the ability to understand the command lines,what they do,what each line is responsible for and having the ability to edit or adjust something,.....etc.
And for the tight schedule;I need to learn everything about android within 6 months (I don't need to learn C as much,but it'd be a bonus),and that's why I go to training centers,faster and more efficient than self learning.
What did u mean by "google skills"?
And what did u mean by "learn java on the android platform"?
Thanks for the help and providing quick answers.
Click to expand...
Click to collapse
You miss understood again...
I will try to be clearer:
I meant by google skills, that you would find most answer yourself if you just use a search engine with the right terms.
You DONT need to learn Java ME/SE etc.
You can and will only use the APIs provided by the android toolkit.
So if you already know java, google "android developement tutorial" and start build some apps to get experience.
Forget C#, you don't need that, AT ALL for android.
Android apps, only need java.
If you want to understand the deeper layers of android, those are written in C.
But "int i=0;" is a variable i with value 0 in java and in C. So if you just want to read some of the code of the deeper layers and change small bits, you don't need to take extra courses in C.
So the conclusion is, you need to understand the android architecture and be able to write apps and have experience...
I would recommend to just think of some thing and write an app for that, learning by doing. Occasionally you can read some theory about the underlying concept of what you are doing.
An example would be to write an app that sorts values the user enters.
You would use already premade sort and array functions from the android api
Something like
Code:
Array x;
x.addAll(y);
x.sort(Descending);
To get deeper knowledge you could then browse the android sourcecode and see how x.sort actually sorts the array.
I think Android application is writen in Java ?
But maybe it is not that your question?
Dark3n said:
You miss understood again...
I will try to be clearer:
I meant by google skills, that you would find most answer yourself if you just use a search engine with the right terms.
You DONT need to learn Java ME/SE etc.
You can and will only use the APIs provided by the android toolkit.
So if you already know java, google "android developement tutorial" and start build some apps to get experience.
Forget C#, you don't need that, AT ALL for android.
Android apps, only need java.
If you want to understand the deeper layers of android, those are written in C.
But "int i=0;" is a variable i with value 0 in java and in C. So if you just want to read some of the code of the deeper layers and change small bits, you don't need to take extra courses in C.
So the conclusion is, you need to understand the android architecture and be able to write apps and have experience...
I would recommend to just think of some thing and write an app for that, learning by doing. Occasionally you can read some theory about the underlying concept of what you are doing.
An example would be to write an app that sorts values the user enters.
You would use already premade sort and array functions from the android api
Something like
Code:
Array x;
x.addAll(y);
x.sort(Descending);
To get deeper knowledge you could then browse the android sourcecode and see how x.sort actually sorts the array.
Click to expand...
Click to collapse
Ok,good,thanks.
So,I don't need EE or ME,right? But if I learn them later on (maybe next year or so),would they come in handy or would they be useless?
I've been developing in Eclipse and SDK with ADT plugin,it's very helpful and I've completed most of the tutorials so far (hello world,tom cat,......etc) and started building something of my own.I've been also using Titanium app accelerator,it's really good too (still mainly eclipse but the tutorials and help are better);but so far all i've done is just copy the code and that's all,I didn't write a single line of code (maybe a few lines,but that's it).
I also started a course a week ago (learning Linux kernel),so far so good,And I found a good site to teach me image files.
But a little hung up on the programming languages section,so,conclusion;I need to learn Java Standard,would enterprise or micro be any good?
And about the native source code,will java be enough? won't I need to learn C?
Thanks for the quick responses,it's a lot of help.
HuTcHx said:
I think Android application is writen in Java ?
But maybe it is not that your question?
Click to expand...
Click to collapse
I already know that,but that's not what i'm asking about.
The enterprise edition and what not just offer different sets of libary for other platforms, aslong as long as you program for android devices you will have little use for knowledge of the other editions.
Think of it as being a specialised technican for cars. They all have engines and 4 tires and a steering wheel and all technicans can work with that, but will you work in a VW repair shop or in the Mercedes repair shop?
In this case you will work on the android platform, as long as you don't want to switch to server programming in java (Java EE) or embedded systems (Java ME), there is no need to get familiar with that.
Java SE means standart edition and basicly already included in the android libaries.
If you don't want to keep copy pasting code, try something different that has not been done in a tutorial, or modifiy a tutorial to do something else.
But there is nothing wrong with copying code, if you have written a good piece of code there is no harm in reusing it elsewhere.
The android sourcecode is a mix of java and C, the lower layers are written in C the higher ones in java.
I don't know what you want to achieve with your knowledge? To write apps you don't need to learn C.
It is difficult to master all fields, easier if you choose one.
Dark3n said:
The enterprise edition and what not just offer different sets of libary for other platforms, aslong as long as you program for android devices you will have little use for knowledge of the other editions.
Think of it as being a specialised technican for cars. They all have engines and 4 tires and a steering wheel and all technicans can work with that, but will you work in a VW repair shop or in the Mercedes repair shop?
In this case you will work on the android platform, as long as you don't want to switch to server programming in java (Java EE) or embedded systems (Java ME), there is no need to get familiar with that.
Java SE means standart edition and basicly already included in the android libaries.
If you don't want to keep copy pasting code, try something different that has not been done in a tutorial, or modifiy a tutorial to do something else.
But there is nothing wrong with copying code, if you have written a good piece of code there is no harm in reusing it elsewhere.
The android sourcecode is a mix of java and C, the lower layers are written in C the higher ones in java.
I don't know what you want to achieve with your knowledge? To write apps you don't need to learn C.
It is difficult to master all fields, easier if you choose one.
Click to expand...
Click to collapse
So,learning java enterprise isn't really important;but is it important if I want to excel in the development process?
But what's the use of learning Micro edition AT ALL when it comes to android development???
Isn't it used to develop apps for feature phones and PDAs,not smartphones?
And after I learn Java standard will I need to learn any special libraries for android? I mean,will I be able to get to writing the code right away or do I need to learn about the android files and libraries? or are they java standard already? I know I need to learn to compile the packages,but is that it?
And what about XML files,I can do them with JDK or Apache Ant,right? so,I don't need to worry about them,do I?
I'm trying to learn as much I can from the dev guide and the tutorials on the developers site,but the dev guide is too long to both read and comprehend,and that's basically a huge problem,cuz I have a job and education and I can't find time to know everything in the dev guide.
I know it'll be difficult to master all fields,but the team I'm going to work with needs someone who's able to edit the deeper layers of the code and,so I think I'll need both java and C for that job,it don't matter anyways I have time to learn both.
Alright before you all have a go on him, I know this isn't the right place to post neither this website but I am active in this site so don't want to create account on another site just to ask this question. I am student and n00b in terms of Programming. I am thinking of joining extra classes in summer vacation. Of course I want to become software engineer. I want to know which will be best language for me to start. C, C++ or dot net? Visual basic looks easy to use but not sure if it has much value in future. I am confused so thought I may get help from these experienced developers. I am in the last year of High School btw.
I am n00b so don't go hard on me If I said anything stupid
friend863 said:
Alright before you all have a go on him, I know this isn't the right place to post neither this website but I am active in this site so don't want to create account on another site just to ask this question. I am student and n00b in terms of Programming. I am thinking of joining extra classes in summer vacation. Of course I want to become software engineer. I want to know which will be best language for me to start. C, C++ or dot net? Visual basic looks easy to use but not sure if it has much value in future. I am confused so thought I may get help from these experienced developers. I am in the last year of High School btw.
I am n00b so don't go hard on me If I said anything stupid
Click to expand...
Click to collapse
Studying C/C++ will be kick start in programming. For future scope, studying Java is good, because Java has its own different fields like Standalone application, web application, and Android of course.
If you're opting for .NET, be sure you're learning the latest version, as .NET versions change from time to time.
And also there are several modern languages like Python, Ruby, Perl etc. Don't know much about its scope.
But everything just emerged from C or Java. So first making a base is what it matters.
EDIT: Don't study Visual Basic as a separate Course, if its included in .NET then its fine. As VB is somewhat a dead technology, most companies are not using it. Studying Silverlight with .NET would be a good choice though.
The best language for me and easy to learn is python programming even noob can create thier own project or apps. bcoz it is embedable in all apps u can understand even if u r n0t a programmer..
Actually any programming language is good to get to know programming in general and to exercise your brain to think/work this way.. oncve you advance a little bit, you will also have the knowledge to know which language to go specific on..
because of my studies, I started with assembler and C, C++, Java, C#.
it depends on what you want to do.
you want to program Android application, use Java, Windows Phone use C#...
i neglected programming on my studies.. i was too lazy. but now i want to be a developer somehow..
so Java for Android applications?
so how about Developing a Rom/Kernel?
Python will be easiest and once you know how to program in one language all others will be much easier to learn.
Sent from my HTC Vision using XDA
Thanks guys, looking forward to it.
The first programing language I used was C.
I've started with C++. But You should try .NET at the beggining. It's so simple. Almost drag&drop method. I used it to create a lot of code generators for my game and other projects.
You should also try AutoIt. Maybe quite harder, but still useable.
I would say, start either with Java or Python.
Why? No specific reason, but they are easy to learn and have a wide area where they can be used later.
I would start with ActionScript 3.0 and/or Java. The first one is the easiest and most fun to program in
If anyone is interested in applications for Android, you should try App Inventor.
http://www.appinventor.mit.edu/
You should try python, becase as others say, it's pretty easy, and if you want to be more motivated, try udacity.com. This is university that operate entirely online. You can view lectures, do quizes, there are also final exams. They start 101 Computer Science (where you learn basics) at 16 april. And guess what, they use python! Even on harder classes.
I wouldn't encourage starting with C or C++. Java and C# are a bit higher level languages and thererfore help you get started faster and let you consentrate on the things that matter most. I would prefer C# over Java as Java has gotten a bit messy in some places, has some gaps in it's standard library, and lacks in standard user interface tools.
Another option to C# would be JavaScript, CSS, and HTML, but the compiler in C# can help you by pointing out mistakes that JavaScript tools can not. Also, if you go this route, don't try to make your code run well on many browsers as that will only cause extra headiche while you are trying to learn the basics. Actually, if you want to use JavaScript over C#, Windows 8 WinRT programming could be a good place to look at. However, it's still in development and lacks in documentation and learning materials when compared to more mature technologies.
If u want work in buisness then go Java. But its very expensive to use because it needs large resources. If u want go for new language try Scala.
JAVA and C++ are the most widely used languages in the world of work today.
But if you want to do web, starts with PHP. It's fairly simple to understand and you can quickly get to Object Oriented concepts, and use simple Design Patterns.