Android Studio don't generate R.java for my import project

Question

I import a project to Android Studio , but the R.java is always empty.

public final class R {
}

I have tried:

Make project,make module, remake, etc.
Project Setting-modules-sources, then add src and gen as my source folder.

But they are not take effect.

That makes two of us. Even in eclipse – Dave Agaba May 18 '13 at 09:19 — Dave Agaba, May 18 '13 at 09:19

score 16 · Accepted Answer · answered Jun 26 '13 at 08:09

16

Goto File -> Settings -> Compiler now check use external build

then rebuild project

answered Jun 26 '13 at 08:09

Kuluval

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I solved this issue doing this as well. I had too many classes with this error. After disabling external build and removing the wrong R imports I had (apparently the cause of my problem), the correct R class was then generated, and I could finally import it in my classes. After everything was fine, I re-checked external builds. Since many people are having this problem, I think I should provide specific details about how that solution worked for me. – davidcesarino Jul 23 '13 at 15:47
19

I don't have **use external build** option. My Android Studio version is 0.8.9 – elvenbyte Oct 23 '14 at 18:33
9

Seems answer outdated. There is no such option nor in 13.1.4 nor in 14 – ruX Nov 11 '14 at 22:59
3

Just use the 'Rebuild Project'from the menu item 'Build' – Jashan PJ Mar 23 '15 at 20:08
Rebuild Project from menu item Build solved my problem – May 08 '15 at 12:22
Only rebuilding didn't work for me. I had to sync the build dir first then rebuild and it worked. – Kalem Sep 29 '15 at 11:48

score 9 · Answer 2 · answered May 09 '15 at 13:09

9

Best Solution for android studio Users :

Goto : Menu tab - > Build - > Rebuild Project

after rebuild Proj. your R.Java file problem will be solve automatically ..

answered May 09 '15 at 13:09

Vijay Patil

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so make sure you doesnt have errors in the xml files – Nativ Oct 26 '15 at 02:26
1

This is quite obvious and would be attempted before looking on this site. – Dale May 02 '16 at 20:05
Wasn't working for me, so after that I created a blank R.java file under tha parent package and then Rebuild Project and it worked. – ishandutta2007 Sep 08 '17 at 03:35

score 5 · Answer 3 · answered Dec 06 '14 at 06:38

5

I managed to regenerate R: File->Settings->Compiler

then UNCHECK "Use in-process build"

Rebuild Project

answered Dec 06 '14 at 06:38

Carlos Gómez

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Setting no longer exists as of Android Studio 1.3 – Kevin Cooper Aug 28 '15 at 20:58
This exists in Android Studio 1.5 - This fixed my issue :) – Matthew Cawley Dec 03 '15 at 14:46

score 4 · Answer 4 · answered Jul 04 '14 at 08:24

4

For me the problem with the R class has been related to automatically organized imports.

As AndroidStudio has the option to allow the automatic imports, it took the wrong R class and thats why the ids have not been found and Gradle was throwing errors!

So check if the import to the R class is referencing to the one you need.

answered Jul 04 '14 at 08:24

stan

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How do you do that? Thanks! – Ricardo May 13 '15 at 15:43
1

@Ricardo take a look at import statements at the top of the class you get error from. If you see import .R and path is something you don't recognize, chances are you are importing wrong R – vanomart Feb 24 '16 at 10:25

score 4 · Answer 5 · answered Aug 11 '15 at 07:40

4

When I was trying to add another flavour I face same situation.

I found in one of post and I gave successful try and it work. Following I did: File -> Invalidate Cached/Restart.

answered Aug 11 '15 at 07:40

CoDe

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score 3 · Answer 6 · answered Jun 03 '13 at 11:46

3

As for me, the problem was in this superfluous line:

import android.R;

answered Jun 03 '13 at 11:46

Cfr

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score 3 · Answer 7 · answered Jul 04 '13 at 21:29

Had the same problem and solved it by:

running / building the project (it was deployed to the device, in my case)
right-clicking on the Project/Module/build folder
choose: Synchronize 'build' - then i found

Project/Module/build/source/r/debug/package/R.java

Probably it was even there before the project was build, but I didn't test that.

I hope this was helpful, even though the answer comes a bit late and by now the bug with the

Settings->Compiler->[ ] Use external build

should be fixed afaik ;-)

This solved the issue for me, while all others failed. I guess there are many reasons for a missing R.. — Karl Ivar Dahl, Dec 16 '15 at 09:24

score 2 · Answer 8 · answered Apr 10 '19 at 19:55

2

So, this is the latest solution if anyone get's stuck like I did today especially, for R.Java file.

If you have lost the count of:

Clean Project

Rebuild Project

Invalidate Caches / Restart

deleted .gradle folder

deleted .idea folder

deleted app/build/generated folder

checked your xml files

checked your drawables and strings

then try this:

check your classpath dependency in your Project Gradle Scripts and if it's, this:

classpath 'com.android.tools.build:gradle:3.3.2'

then downgrade it to, this:

classpath 'com.android.tools.build:gradle:3.2.1'

answered Apr 10 '19 at 19:55

Rohit Sharma

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but why? i mean it works, but whats the reason that a newer version essentially breaks. – Emile May 15 '19 at 15:37
Not quite sure @Emile but more stabler version may be one of the reason to answer this, also sometimes while updating dependencies such things might have been overlooked. – Rohit Sharma May 16 '19 at 17:02

score 1 · Answer 9 · answered Feb 03 '16 at 10:10

1

If you are facing this problem in a specific module in your project, you could try opening just that module as a project and then build it. This worked for me. It was failing to generate the R file for the module when I was trying to re-build the entire project.

answered Feb 03 '16 at 10:10

ben_joseph

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Amazing. That was happened to me. Your answer worked like a charm. – Abdalrahman Shatou Apr 21 '17 at 20:02

score 1 · Answer 10 · answered May 17 '16 at 18:29

1

Check your project package! I had brought some classes over from another project and did not notice the subtle change in the package name. See top of your AndroidManifest.xml

answered May 17 '16 at 18:29

tom

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score 1 · Answer 11 · answered May 31 '18 at 15:59

1

File->Invalide Cahces / Restart

answered May 31 '18 at 15:59

Kusan

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score 0 · Answer 12 · answered May 18 '13 at 10:51

0

Did you follow steps here? First update your Eclipse ADT plugin, then export project and the import in Android Studio.

http://developer.android.com/sdk/installing/migrate.html

answered May 18 '13 at 10:51

fasteque

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score 0 · Answer 13 · answered May 18 '13 at 12:15

I had a lot of problems exporting a project from Eclipse (assuming that is where you are exporting from). It was much easier for me to create a new project in Android Studio, then copy over the java files, xml files, layout directories, etc, and the AndroidManifest, into the appropriate location in the new project.

If you already have an R.java file for your project, you could try just copying it over to the new project. In Android Studio the R.java file seems to reside in build/source/r/debug/your-package-name/

score 0 · Answer 14 · edited May 23 '17 at 11:47

0

I found my solution here. In short make sure not only the Eclipse plugin(if you are using eclipse) is updated. Also ensure that the Android SDK Tools, the SDK platform-tools and the SDK Build-tools are updated. After this restart your machine.

edited May 23 '17 at 11:47

Community

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answered May 18 '13 at 12:50

Dave Agaba

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Thank you,but in fact this error occurred in Android Studio not Eclipse – Marshal Chen May 19 '13 at 12:05
Studio I think also uses the Android SDK. And That's where the problem might be. So try it out. – Dave Agaba May 19 '13 at 14:12
Android Studio has it's own version of the Android SDK in the dir "//sdk" – Quasaur May 21 '13 at 22:28

score 0 · Answer 15 · edited May 23 '17 at 12:02

0

I failed even if I tried to update the SDK tools as mentioned here.

Here is how I solved the problem (for the library projects imported).

In File -> Project Structure -> Modules, I removed the problematic projects, and added them again by selecting New Module -> Android Library Module.

Select "Android Library Module" when adding project.

After rebuilding the project, I got all the R.java files back.

edited May 23 '17 at 12:02

Community

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answered Jul 11 '13 at 12:46

Yi H.

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I think you also can go in the "Facets" section, then click "Add", choose "Android" and apply it to your library modules. Then go on the "modules" node and select "Library module". Could be quicker than reimporting everything (but maybe was not available in previous releases of android studio) – Christophe Fondacci Dec 12 '13 at 00:36

score 0 · Answer 16 · answered Nov 05 '13 at 11:40

I will answer the question even though it has been a long time since it was thrown, just in case someone else get to it.

Tested on Android Studio ONLY (but I guess it could work for Eclipse as well) :

Check your build/source/r folder. In there, you should find some directories labelled under the name of your gradle build name (default : debug). Verify that the name of the package associated with R is the one you want.

I know this trick solves the problem of switching namespace, because Android Studio (or Gradle I don't know who is responsible for that) seems not to regenerate it in that case.

I haven't tried it when importing a project from Eclipse though.

score 0 · Answer 17 · edited Mar 08 '15 at 21:00

0

Go to File → Settings → Editor → Auto Import and at java tab you should have:

Insert imports on paste: ASK.
If you have import for ALL, then Android Studio import other file.

edited Mar 08 '15 at 21:00

grg

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answered Mar 08 '15 at 15:55

score 0 · Answer 18 · answered Mar 23 '15 at 20:09

0

Just use the 'Rebuild Project' from the 'Build' menu from the top menu bar.

answered Mar 23 '15 at 20:09

Jashan PJ

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score 0 · Answer 19 · answered Oct 26 '15 at 23:42

I had a similar problem in a large multi-module project with many dependencies among the modules. What worked for me, was to attempt to build separately from command line all the modules that failed to build within Android Studio. That gave me indications on resources missing in each project. From the project level in my console I did:

$ cd moduleName
$ ../gradlew assembleDebug

This provided me with a number of 'No resource found that matches the given name' errors, that weren't shown before, when I build the project as a whole.

after doing this, I could finally import R again. Thank you!! It has something to do with multi-module-project. My lib-module was corrupted. — Tom Bevelander, May 17 '16 at 21:47

score 0 · Answer 20 · answered Feb 04 '16 at 10:20

0

I had a similar problem within my project using Android Studio 1.5.1. For me, bulding the project from command line by using following command resolved the problem:

gradle assembleRelease

answered Feb 04 '16 at 10:20

bogumil

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score 0 · Answer 21 · answered Jul 30 '18 at 18:31

0

In my case I had an empty line prior a drawable definition in xml. This was braking aapt essentially not allowing to generate R.java .

answered Jul 30 '18 at 18:31

foo

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score 0 · Answer 22 · edited Jan 21 '19 at 02:35

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I had this problem after update gradle...

There are several reasons that causes the project not to be built:

1-Unknown error in drawable or xml files

2-Update gradle or libraries and etc ...

Solution :

1-Clean and rebuild project

2-Delete .idea and build folders in project file(shown in picture) then goto "File/Invalidate catch-restart"

3-Roll back to previous gradle version and libraries.

edited Jan 21 '19 at 02:35

Hamed Jaliliani

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answered Jan 20 '19 at 16:46

Maryam Azhdari

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score 0 · Answer 23 · answered Jun 28 '23 at 20:55

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This is an edge-case:

I rename my module name and I forget to rename the namespace in my build.gradle file so when I tried to build the proyect the R class never was created.

I fixed it renaming the namespace and the problem was solved.

answered Jun 28 '23 at 20:55

LordCommanDev

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score -1 · Answer 24 · edited Mar 28 '14 at 10:37

-1

Go to Menu-Tab -> Project -> Build -> Automatically(check this option). and than reopen a new project.

edited Mar 28 '14 at 10:37

Mystery

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answered Mar 28 '14 at 10:16

user3440768

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Android Studio don't generate R.java for my import project

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