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Cleanning Project deletes R.java files

My project works fine without any error until i clean it . When i clean my project deletes all R.java files in and doensn't recreate them. I looked lots of posts but i couldnt solve my problem.
My drawebles seems fine.
I also tried to check my layout files but i couldn't see anything wrong with them.
As i said it works fine until clean. I can run it or debug it.Also when i started my project it gives lint error.Is there any solid solution for this situation.

Lint error usually occurs when you have more than one eclipse running on your computer. And about R.java error, restart eclipse/check your android manifest file, sometimes you may find some problem in your manifest. It is yet not clear why the clean removes R.java. Even check for Properties of the project in Android and Java Build Path options, to see if appropriate options are ticked! Hope you get success! Thanks..

R.java file just went missing

I'm working on my app and for this activity I was going to build a new layout file for it. However eclipse gave me an error stating that layout was not updated in the R.java file. So I read online that modifying manifest would update the R.java file but it didn't. So I clicked on clean project and my R.java file disappeared propagating errors across all my src files. Now I heard that it could be due to layouts named with capital letters but all my layouts start with small letters. Also even if I manually add a R.java file and click on clean, the R.java disappears after. I really don't know what to do now. I also tried most of the solutions from the similar questions but to no avail.

Any error on XML files will prevent R generation.
Check for mark errors and Eclipse console (some errors when parsing XML are shown there).
Also I've seen Eclipse generates some dumb files with .out.xml or .xml.out extensions. I'm not sure why it happens, but any "allien" file on res folder also prevents R to be regenerated.

Thanks for your help guys. I tried to look at every file to check for errors but after 30 minutes of scratching my head, I just opened a new project and copied each file to the new project and that is working now.

R.java was modified manually! Reverting to generated version

I added one xml file in layout. After that this error is coming. But the problem is I haven't touched R.java file.
Now in my new activity i m going to set its content view as my newly created xml file, but when i m doing R.layout., the newly created xml is not coming in suggestion. Do anybody have any idea how to correct this.
I have cleaned my project several times but it is not working.

Delete R.java and let eclipse regenerate it, then project --> clean will fix it.

Check if you have any existing errors in your code, if yes correct it and then try refreshing and building your Project.If your Project is properly build,you will get the new xml file in suggestion

It happened to one of my Eclipse projects today. This is what fixed it mysteriously. Don't know why or how.
Changed Properties->Android->Project Build Target to a higher (different) version of Android and hit the Apply button. Then did a clean build. The problem went away.
After the above steps, I could even go back to the original Project Build Target without the problem re-appearing.

May this Help you...
I think your xml file name might be having some capital letters or some special characters..
Delete them and then try again to run the project..

Try cleaning the project this will do the work.

make sure your not importing any thing that ends with com.R
make sure your naming convention of the layout is correct

R.java file have all the resources IDs provided to resources(drawables, layouts, styles etc) either by Programmer, or generated through sdk. So check your xml files as well as your drawable folders. If any of them including wrong format it will show an error in R.java file like sometime R.java is not generating or our class file shows R.id.xxx is not found or R.class is not defined error.Then clean your project.

There must be some mistake in one of your xml files. Eclipse does not always show error messages if there is something wrong with your xml. Mostly code gets errors, in this case 'R', so you will need to go through your xml manually, it could just be a simple mistake. Good luck

I had similar problem. Cleaning project didn't solve the issue and there was no error in the code or the uppercase or spaces in file names.
The solution was going to a popup window which came when you choose PROJECT-->CLEAN and then UNcheck the "Start a build immediately" option. Clean the project. Close and reopen Eclipse and then build the project (PROJECT-->BUILD).
The question remains why simple clean and build without closing Eclipse didn't worked.

Right Click on Project->Bulid Path->Configure Build Path
ther you see error android-support-v4.jar remove this library and add library again this works fine for me.
Else
Try
Go to gen Folder delete R.java and from Project option choose Clean Project.

Very late on the scene...
I had this line mysteriously appear at the start of my imports:
import android.R;
I deleted it and shazam error was gone.

I had similar error, but when I import new project to my eclipse. and the solution was, I should check the option (copy project to work space) specially when our project has library.

R.java file missing from gen folder in eclipse

My PC went to sleep while battery was low. But when it recovered I found R.java file missing from my gen folder. My entire application is under crash.
The error is shown below:

If you recently added a new resource file and happen to use upper case letters in the file name, change the file name to lowercases and rebuild your project. That is what happened to my project.
The R.java file should be regenerated every time you do a rebuild of your project.

Clean the project,
Go through your code and remove all references to android.R.*
So when your R.java is corrupt or missing Eclipse tries to be helpful and thinks that the references in your code for R.something are missing the import file and inserts the android.R.* to your import list.
If you are using IntelliJ it has a rebuild R.java command.
If it is still missing then it means that something in your code is preventing it from being built. Pay attention to resource file names etc. Usually you can sport these naming problems in console view of eclipse

There are possible chances, you have a problem in your layout xml or in your code.
Try looking at file that you had open in your eclipse when it went to sleep, and code snippet that you were working at.
Edit:
R (resource file) regenrates at every rebuild of your project. For some error in your project your project wasn't able to build that why your R file is missing. All that you need to do is to fix issue in your files, code and xml files.

I got the same issue. Nearly I spent whole day working on it to figure out the reason and tried all the 100 solutions provided in the blogs. But nothing helped!!! After setting up a new workspace I figured out. Remove unnecessary libraries in your project. You can check this by Project-> right click-> properties-> Android-> and remove unnecessary added libraries. It worked :) Hope it helps some one.

R.java disappeared

I recently downloaded the Android Support Package and have been using it trying to get my application, running at SDK 10, to use a GridLayout.
Anyway, I cleaned my project a few times working on this error in my XML files, and then when I went back to my classes in /src, every single reference to R.* was an error.
This has happened to me before, but it usually fixes itself, and it has not yet. Does anyone know what to do?
The R.java file is no longer in my /gen folder.

It sometimes happens when you import another project First i suggest you to build it, it will create automatically .
If it's not working then try to create new project from existing source and specify the downloaded project . It worked for me
Hope this works for you let me know..

Sometimes if there is an error in your XML files R.java won't build. Go through your XML files to make sure that everything is in order (typo, forgetting to close a bracket, etc). When you fix that it should build itself again.

You can also try Adnroid Tools>Fix Project. That may help you to create gen/R.java file

Follow following steps :
In Eclipse,
=> Right Click on Project > Android Tools > Fix Project
By this way, you can fix many common problems which can help generate R.java in gen/R.java file.

There can be several reasons why this occurs. The following I have found happen to me and I have included the steps I took to resolve them.
First step is to try and clean the project (from the Project menu option I believe)
Check there are no errors with your XML files. Sometimes this is obvious from the red 'x' that appears next to an XML filename in the Project exlporer window and sometimes it is not. If it is not obvious check the 'Errors' window (whic is founf in the 'Windows' Menu option
Failing that I have found that by disabling the automatic build option, adding some arbitrary comment to an arbitrary source file, saving the source file, clean the project, remove the comment and then re-selcting automatic build can work too.
Apologies for the approximate locations for some of the Eclipse functions but I am not currently in front of Eclipse to check.

This happens when you have an error in the res folder.
Fix the error first, then do :
Project --> Clean --> Ok
Et voila !