How to make a .jar out from an Android Studio project

Question

I'm using AndroidStudio and I have this project as shown:

enter image description here

What is inside the blue circle is myLib. myLib also needs to use an external lib that is inside the red circle, and an apache package (green circle).

So I want to make this whole thing become a single .jar, so I can use it in another projects.

A step-by-step guide would be really appreciated, I'm a beginner in the developer world.

Thanks!

I think what you want is a aar file (Android archive) that one can be linked quiet simple as dependency. Basically you need to create a Android library project. But I cannot write the exact steps from mind. — rekire, Feb 11 '14 at 20:55
I need a .jar file so I can use in any java project. Not only android's. — dum4ll3, Feb 11 '14 at 20:58
Must be almost the same - make a library project and the export it. — Thrash Bean, Feb 11 '14 at 21:00
[This bug](https://code.google.com/p/android/issues/detail?id=58287) describes a deficiency in the Android gradle plugin that prevents easily hacking the gradle buildfile to add a jar target... — mmigdol, Feb 11 '14 at 21:25

score 149 · Answer 1 · edited May 20 '20 at 12:22

149

Open build.gradle for library project
Write two tasks in build.gradle -- deleteJar and createJar and add rule createJar.dependsOn(deleteJar, build)

The code from above:

task deleteJar(type: Delete) {
    delete 'libs/jars/logmanagementlib.jar'
}           

task createJar(type: Copy) {
    from('build/intermediates/bundles/release/')
    into('libs/jars/')
    include('classes.jar')
    rename('classes.jar', 'logmanagementlib.jar')
}

createJar.dependsOn(deleteJar, build)

Expand gradle panel from right and open all tasks under yourlibrary->others. You will see two new tasks there -- createJar and deleteJar
Double click on createJar
Once the task run successfully, get your generated jar from path mentioned in createJar task i.e. libs/xxxx.jar
copy the newly generated jar into your required project's lib folder-->right click-->select "add as library"

edited May 20 '20 at 12:22

Sirop4ik

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answered Feb 16 '16 at 11:31

Abhinav Tyagi

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@AbhinavTyagi Have a library in my Android project, but whenever I change the source of the library, the changes are not affected to .jar file, its still maintaining old code in .jar. I have tried build, createjar etc. Any ideas? – nucleons Feb 10 '17 at 13:09
Whenever I made any changes, I had to run the tasks again as shown above. Try cleaning the build and rerun the scripts when you have made changes. – Abhinav Tyagi Feb 10 '17 at 13:12
1

You know this would be much better if it didn't involve screenshots. – Cameron Lowell Palmer Apr 07 '17 at 13:04
9

Sometimes people understands by viewing rather than reading. It's a good UX you see ☺ – Abhinav Tyagi Apr 07 '17 at 13:06
I fixed it for you :) – Cameron Lowell Palmer Apr 07 '17 at 13:45
Thanks... But I wanted people to type to have some finger exercise :D – Abhinav Tyagi Apr 07 '17 at 13:47
5

Well, then I should tell you that I'm not sure about `release`. I've got `debug` and `default`, but no `release` folder. What version of the plugin are you using? Do you know if this is documented anywhere? – Cameron Lowell Palmer Apr 07 '17 at 14:01
3

I don't have `release` folder. – Kamran Bigdely Apr 10 '17 at 16:39
try and replace the release folder with what you want. see if it works for you. – Abhinav Tyagi Apr 10 '17 at 16:49
3

Use `default` if you don't have `release`. Changing to that fixed my issue. – Kamran Bigdely Apr 11 '17 at 22:17
@kami +1 to use `default` or `debug` – stepheaw Aug 14 '17 at 23:00
2

I don't have `bundles` folder so no `classes.jar` appearing and have nothing to copy. what can i do to solve this? – user2890234 May 08 '18 at 13:30
@user2890234 check above comments. Use the folders you have and modify the script. – Abhinav Tyagi May 09 '18 at 05:52
1

@Abhinav Tyagi, thanks for your answer. but above comments solve lack of `release/debug/default` folders while i even have no `bundles`, so no `classes.jar` creating when running `createJar` – user2890234 May 09 '18 at 10:00
4

What are you trying to copy?? Are we supposed to target the folders containing the APK file?? I mean in the line from('build/intermediates/bundles/default') what is this directory holding for you. There is no folder in my android studio with the name bundles, and I keep getting NO SOURCE in createJar task – Bawender Yandra May 24 '18 at 09:30
18

change from('build/intermediates/bundles/release/') to from('build/intermediates/packaged-classes/release/') for Android Studio 3.1.3 and Gradle version 4.4 – Vaishakh Jul 16 '18 at 15:24
I don't have the 'intermediates' fold in 'build'... Android studio 3.2.1 – steven Oct 22 '18 at 06:09
you can check build/outputs/apk – Abhinav Tyagi Oct 22 '18 at 07:14
3

I don't see even this folder build/intermediates/packaged-classes/release/ – Pinkesh Darji Feb 07 '20 at 11:09
I'm using Android Studio 4.1.1 and using folder 'build/intermediates/app_classes/release' – Elinx Feb 20 '21 at 01:30
need not to create a new one ,it aready had a createFulJarRelease/createFullJarDebug，double click and it will build a full.jar which is what need – Michael Yang Nov 05 '21 at 05:16

score 63 · Answer 2 · answered Feb 11 '14 at 21:58

63

If you set up the code as a plain Java module in Gradle, then it's really easy to have Gradle give you a jar file with the contents. That jar file will have only your code, not the other Apache libraries it depends on. I'd recommend distributing it this way; it's a little weird to bundle dependencies inside your library, and it's more normal for users of those libraries to have to include those dependencies on their own (because otherwise there are collisions of those projects are already linking copies of the library, perhaps of different versions). What's more, you avoid potential licensing problems around redistributing other people's code if you were to publish your library.

Take the code that also needs to be compiled to a jar, and move it to a separate plain Java module in Android Studio:

File menu > New Module... > Java Library
Set up the library, Java package name, and class names in the wizard. (If you don't want it to create a class for you, you can just delete it once the module is created)
In your Android code, set up a dependency on the new module so it can use the code in your new library:
File > Project Structure > Modules > (your Android Module) > Dependencies > + > Module dependency. See the screenshot below:
Choose your module from the list in the dialog that comes up:

Hopefully your project should be building normally now. After you do a build, a jar file for your Java library will be placed in the build/libs directory in your module's directory. If you want to build the jar file by hand, you can run its jar build file task from the Gradle window: enter image description here

answered Feb 11 '14 at 21:58

Scott Barta

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Thank you very much! Your answer was really helpful, most in the last screenshot that shows the Gradle tasks. I didn't know that. I could follow your the steps, but I still missing the org.apache.http.Header. How can I import it into my lib? – dum4ll3 Feb 12 '14 at 16:04
What do you mean when you say you're missing it? – Scott Barta Feb 12 '14 at 16:34
I can't import it. Like when you hit Ctrl+Space to see the imports' options, org.apache.http.Header isn't there. But I see others like com.sun.xml...Header. – dum4ll3 Feb 12 '14 at 16:39
If you're running a version of Android Studio earlier than 0.4.3, that's your problem -- please upgrade. – Scott Barta Feb 12 '14 at 16:50
I'm using 0.4.4. It seems like when you create a new Java Library (File menu > New Module... > Java Library) it comes without the apache's package. I miss it in my lib module, not in my app's. So how can I import this specific package inside my lib module? – dum4ll3 Feb 12 '14 at 17:07
Oh, you have to make sure it's in your lib module's dependencies, too. – Scott Barta Feb 12 '14 at 17:13
Yeah, it's not, so how can I fix it? And a last doubt, when I execute a gradle jar task, where can I find the resulting .jar file? Anyway, Im really grateful for your help! :) – dum4ll3 Feb 12 '14 at 17:33
1

Go through the same Project Structure > dependencies flow, but choose your library module instead of your project, and add the dependency in the same way. In my answer I say that it puts the jar file in the build/libs dir in its module directory. – Scott Barta Feb 12 '14 at 17:49
2

I got: java.lang.NoClassDefFoundError: com.loopj.android.http.RequestParams. That's my external library I'm compiling with mine. – dum4ll3 Feb 12 '14 at 20:09
Hi Scott, it doesn't feel right to have to do this to get a jar file for a microsoft sponsored project on github. I'm trying to use SignalR Android client in my android studio project and I must have taken a left turn somewhere. Surely I should not make my jar and put the MS "jar" inside of it. Thanks. – toddmo Apr 12 '15 at 00:54
2

It work with java library only, and jar task in android library not exist – cuasodayleo Dec 31 '15 at 02:57
When I move my classes into a new module, android studio complains about all the import statements I've used saying (e.g.) 'cannot resolve symbol Intent'. – Kamran Bigdely Apr 10 '17 at 16:42
I resolved my import issue (cannot resolve symbol) by creating **Android Library** instead of Java Library (**New Module... > Android Library**) – Kamran Bigdely Apr 11 '17 at 22:21
In the latest version of Android Studio (3.4.1) the gradle script is called 'createFullJarDebug' and 'createFullJarRelease' respectively. – moonlightcheese Sep 21 '19 at 09:12

Haroun Hajem · Answer 3 · 2020-05-14T07:29:11.813

40

In the Android Studio IDE, access the "Run Anything bar" by:

CTRL+CTRL +gradle CreateFullJarRelease+ENTER

After that you'll find your artefact in this folder in your project
Build > Intermediates > Full_jar > Release > CreateFullJarRelease > full.jar

OR

Gradle has already a Task for that, in the gradle side-menu, under the other folder.

Then scroll down to createFullJarRelease and click it.

After that you'll find your artefact in this folder in your project

Build > Intermediates > Full_jar > Release > CreateFullJarRelease > full.jar

edited May 14 '20 at 07:29

answered Oct 06 '18 at 16:56

Haroun Hajem

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4

Can't see this option. Has this been added on a recent Studio version ? – Dibzmania Dec 24 '18 at 03:30
1

I build and when find *.jar it's name is : full.jar. 30mins to found it lol – nobjta_9x_tq Mar 07 '19 at 09:09
1

In my case, I found it in `build\intermediates\intermediate-jars\release` – Yusril Maulidan Raji Oct 09 '19 at 11:15
I have a question. In my case, it generates 3 jar files. `classes.jar`, `full.jar`, and `res.jar`. Should I import all jar files whenever I want to use it? – Yusril Maulidan Raji Oct 09 '19 at 15:09
Just use the full.jar – Haroun Hajem Oct 10 '19 at 06:55
Please explain what your first image is. It looks like a menu. How do we get there? – Steve White May 09 '20 at 15:54
@SteveWhite Yes it's the Gradle menu/toolbar, can be found on the right side in the Android IDE. Or on the keyboard dubble tap CTRL then type "gradle CreateFullJarRelease". =) – Haroun Hajem May 13 '20 at 21:15
I don't have the `createFullJarRelease` option, only `createMockableJar`. Any reason why this might be? – HB. Sep 02 '20 at 05:40
My answer was posted 2018, could be that Gradle have changed the name of the Gradle task or removed those tasks. Haven't check that for a while. – Haroun Hajem Sep 03 '20 at 19:45
1

my output was in app/build not build – Alireza Jamali Sep 18 '21 at 18:05

score 12 · Answer 4 · answered Nov 26 '16 at 04:41

12

Simply add this to your java module's build.gradle. It will include dependent libraries in archive.

mainClassName = "com.company.application.Main"

jar {
  manifest { 
    attributes "Main-Class": "$mainClassName"
  }  

  from {
    configurations.compile.collect { it.isDirectory() ? it : zipTree(it) }
  }
}

This will result in [module_name]/build/libs/[module_name].jar file.

answered Nov 26 '16 at 04:41

Bao Le

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But would a .jar library have a Main class? The OP says they're building a .jar file "so I can use in another projects" (sic). That sounds like a library. – Steve White May 09 '20 at 16:01
Only this guy actually understood that, just jar creation doesn't solve prob. what if we need to execute it. Above code avoids "Can't execute jar- file: “no main manifest attribute”" error. – MobileEvangelist Jul 22 '20 at 12:49

score 2 · Answer 5 · answered Nov 05 '21 at 05:21

I had a supplement; In the new version Android Studio(for me is: Android Studio Arctic Fox | 2020.3.1 Patch 3 Build #AI-203.7717.56.2031.7784292, built on October 1, 2021) In gradle panel, it has no task in default. Go to the Android Studio ---Settings--Experimental--Gradle tab, uncheck"Do not build Gradle task list during Gradle sync", then click File--Sync project with Gradle files, then the task appeared in the Gradle Panel.

Then follow the answer: https://stackoverflow.com/a/52681317/4065069

score 1 · Answer 6 · answered May 28 '19 at 10:00

task deleteJar(type: Delete) {
    delete 'libs/mylibrary.jar'
}           

task exportjar(type: Copy) {
    from('build/intermediates/compile_library_classes/release/')
    into('libs/')
    include('classes.jar')
    rename('classes.jar', 'mylibrary.jar')
}

exportjar.dependsOn(deleteJar, build)

score 1 · Answer 7 · edited Dec 03 '19 at 21:43

1

Go to Gradle tab in Android Studio , then select library project .
Then go to Tasks
Then go to Other
Double click on bundleReleaseaar

You can find your .aar files under your_module/build/outputs/aar/your-release.aar

edited Dec 03 '19 at 21:43

Badro Niaimi

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answered Dec 03 '19 at 19:51

Dame Gjurcinoski

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I don't see any "Gradle Tab" anywhere. Finally I typed "Gradle" in the Help search, and got something like your Gradle view. But the list inside is very different, much shorter than yours. There is no bundleReleaseaar under Tasks->Other. There is a "createJar", but when I click that, I get "Task 'createJar' not found in root project..." I'm stuck. And... why do we want .aar files? The OP asked for a .jar file. Is that the same thing> – Steve White May 09 '20 at 16:13
But question is how to make `.jar` not `.aar` – Sirop4ik May 20 '20 at 13:09

score 1 · Answer 8 · answered Jan 01 '22 at 11:47

In case of this accepted answer not working for you

Use this

task createJar(type: Copy) {
    from('build/intermediates/packaged-classes/release/')
    into('libs/jars/')
    include('classes.jar')
    rename('classes.jar', 'plugin.jar')
}

Instead of this

task createJar(type: Copy) {
    from('build/intermediates/bundles/release/')
    into('libs/jars/')
    include('classes.jar')
    rename('classes.jar', 'logmanagementlib.jar')
}

score 0 · Answer 9 · answered Jul 17 '17 at 09:37

0

the way i found was to find the project compiler output (project structure > project). then find the complied folder of the module you wish to turn to a jar, compress it with zip and change the extension of the output from zip to jar.

answered Jul 17 '17 at 09:37

yaniv

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score 0 · Answer 10 · answered Nov 23 '17 at 08:11

0

.jar file will be automatically generate when u compile/run your application.

You can find your class.jar file from root_folder/app/build/intermediates/bundles/debug

answered Nov 23 '17 at 08:11

Sonia John Kavery

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yoAlex5 · Answer 11 · 2021-01-23T16:05:31.090

If you use

apply plugin: 'com.android.library'

You can convert .aar -> .jar

If you run a gradle task from AndroidStudio^[More]

assembleRelease 
//or
bundleReleaseAar

or via terminal

./gradlew <moduleName>:assembleRelease
//or
./gradlew <moduleName>:bundleReleaseAar

then you will able to find .aar in

<project_path>/build/outputs/aar/<module_name>.aar
//if you do not see it try to remove this folder and repeat the command

.aar^[About] file is a zip file with aar extension that is why you can replace .aar with .zip or run

unzip "<path_to/module_name>.aar"

How to make a .jar out from an Android Studio project

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