How to build JARs from IntelliJ IDEA properly?

Question

I have a project that contains a single module, and some dependencies. I'd like to create a JAR, in a separate directory, that contains the compiled module. In addition, I would like to have the dependencies present beside my module.

No matter how I twist IntelliJ's "build JAR" process, the output of my module appears empty (besides a META-INF file).

Hanging

Answer 1

Instructions:

File -> Project Structure -> Project Settings -> Artifacts -> Click + (plus sign) -> Jar -> From modules with dependencies...

Select a Main Class (the one with main() method) if you need to make the jar runnable.

Select Extract to the target Jar

Click OK

Click Apply/OK

The above sets the "skeleton" to where the jar will be saved to. To actually build and save it do the following:

Build -> Build Artifact -> Build

Try Extracting the .jar file from:

📦ProjectName
 ┗ 📂out
   ┗ 📂artifacts
     ┗ 📂ProjectName_jar
        ┗ 📜ProjectName.jar

References:

• (Aug 2010) http://blogs.jetbrains.com/idea/2010/08/quickly-create-jar-artifact/ (Here's how to build a jar with IntelliJ 10)
• (Mar 2023) https://www.jetbrains.com/help/idea/compiling-applications.html#package_into_jar

Waltner

It fails when some classes in your included jar are signed with RSA. – Natiha

Link is dead. Do you have a copy of this article? – Bemoan

This creates a jar file with the class files (and the structure) only. I'm using gradle. – Abbey

For me it worked on 2016.2.1, but you have to first check the mark "Build on make" in the menu where you set the output directory, then you have to Run the application in Intellij so it generates the jar – Kerril

how can generate Tomcat embedded jar? – Perfecto

@AsifShahzad see this answer for building jar files with signed dependencies: #41746677. – Dermott

This method still fails, the jar file doesn't execute – Shatter

Be reminded to choose the correct Main Class, while doing Create JAR from Modules. Otherwise the JAR file will never work as you expected. – Disorderly

It seems someone has really worked very hard to not make it work. It is such a shame it never works. I have tried at least 50 different answers and none of it worked. And its the same story every single time. Now I reserve a week to just output it as a jar as everyone in our company thinks its a genuine effort that needs to be go in producing an output jar. – Tynishatynwald

As many wrote before me, this is a simplification that sometime works. Please see @zsolt tolvali's answer below. It would be good from IntelliJ's perspective to make the JAR creation process a DEFAULT ACTIVITY when creating a new project, because very few people do not need it! – Desirable

I sleected class, but get error message: "not acceptable" – Accelerando

it is almost 2020, and we have self driving car almost and we still can not figure out how to create executable jar in Intellij – Hiramhirasuna

I can't thank you enough for this after literally wasting 2 hours of my life trying to figure out how to tell Maven that I want the dependencies to come with the generated jar. – Majewski

After trying 100 times to make a jar using intelliJ, I finally found a solution. Open Eclipse --> export as Jar. Done. – Levee

how are Java IDEs still so garbage... this is insane – Mcclure

@Hiramhirasuna The worst hour of my life I spend trying to figure out how to get an executable of a java project. – Prole

2022-03-03: I can say that this approach worked well with IntelliJ IDEA 2021.3.2 (Ultimate Edition) – Demmer

Thank you SO MUCH! I wish I could award extra points for this <3 – Gravettian

none of these solutions ever works – Spastic

my honest suggestion, in case of trying to build one using intellij, one can use the command line to build a jar. (assuming its a small jar and you are not using maven to get it done) – Ctesiphon

Answer 2

This is still an issue in 2017, I hope it will help somebody out there! I found 2 possibilities to create working jar-s under IntelliJ 2017.2

1. Creating artifact from IntelliJ:

• Go to project structure:

• Create a new artifact:

• Select the main class, and be sure to change the manifest folder:

You have to change manifest directory:

<project folder>\src\main\java 

replace "java" with "resources"

<project folder>\src\main\resources

This is how it should look like:

• Then you choose the dependencies what you want to be packed IN your jar, or NEAR your jar file

• To build your artifact go to build artifacts and choose "rebuild". It will create an "out" folder with your jar file and its dependencies.

2. Using maven-assembly-plugin

Add build section to the pom file

    <build>
        <plugins>
            <plugin>
                <artifactId>maven-assembly-plugin</artifactId>
                <configuration>
                    <finalName>ServiceCreate</finalName>
                    <appendAssemblyId>false</appendAssemblyId>
                    <archive>
                        <manifest>
                            <mainClass>com.svt.optimoo.App</mainClass>
                        </manifest>
                    </archive>
                    <descriptorRefs>
                        <descriptorRef>jar-with-dependencies</descriptorRef>
                    </descriptorRefs>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>
        </plugins>
    </build>

• Create a new run/debug configuration:

• Choose application:

• Fill in the form
• Add the "assembly:single" maven goal after build to be executed last

• Save it, then run

This procedure will create the jar file under the "target" folder

Elvyn

change manifest directory to src/resources is the key point !!! thanks~ – Raasch

I was getting no main manifest attribute adopting above solutions. No one has mentioned changing the path to manifest. Thnx!! – Guacharo

how about source code in scala ? java is not what I'm using – Monkey

Instead of resources, you can also change the directory to the one above java, e.g. ...\src\main\java -> ...\src\main and it works. Jet Brains should really fix this default, it's still a problem in 2020.1.4. – Showpiece

@Showpiece I think they fixed it. The default is now ...\src\main\resourses and if you don't have a manifest file there, a file will be created automatically. – Somatoplasm

I am getting no main manifest attribute, but it is in there and I followed all the gradle steps perfectly? – Tuckerbag

@RoyCohen No. It's still \src\main\java , IDEA 2021.3 – Nitride

how to add version numbers in generated jar file, if lets say I updated the code and build artifacts, then each time its generating same jar file without any version number, how this version can be appended to the generated jar file – Corvin

What's the differences between these 2 methods? – Haase

The first method is configuring IntelliJ to build the artifact, the 2nd one is adding a build plugin to the pom file. – Elvyn

Run it with java -jar "ServiceCreate.jar" – Leucocyte

Answer 3

I recently had this problem and think these steps are easy to follow if any prior solution or link is missing detail.

How to create a .jar using IntelliJ IDEA 14.1.5:

1. File > Save All.
2. Run driver or class with main method.
3. File > Project Structure.
4. Select Tab "Artifacts".
5. Click green plus button near top of window.
6. Select JAR from Add drop down menu. Select "From modules with dependencies"
7. Select main class.
8. The radio button should be selecting "extract to the target JAR." Press OK.
9. Check the box "Build on make"
10. Press apply and OK.
11. From the main menu, select the build dropdown.
12. Select the option build artifacts.

Struthious

did you miss something ? There is an option about module what should be that. In my case it's creating JAR but JVM through error due to security. – Filtration

i think that list is everything. You might have something with your java settings stopping it due to security. Does anyone else have thoughts on this? – Struthious

Followed the same and I have Error: Could not find or load main class JavaFundamentals.jar when running this jar file. Explained here: #40637290 – Knout

Does this 12 step process have to be taken every time I want to build a jar, or will IntelliJ remember these actions so you can use a shortcut to it? – Calctufa

Answer 4

For those that benefit from images as I do:

File -> Project Structure

Karyolymph

@samuelowino i don't appreciate you saying that. Explain what "doesn't work at all". – Bradytelic

Hey @Karyolymph I was not checking the right jar file, apparently, Inteliji produced two jar files on different directories, apologies, my bad, your solution works, thanks – Shatter

@Karyolymph I tried the above steps. but i keep getting no main manifest attribute, in myFile-0.1.jar – Linebacker

Answer 5

Here are 2 examples with maven project, step by step:

Method 1: Build jar with maven and pom.xml

1. File, new, project, maven
2. create a package , create a java program inside that package

3. at pom.xml, add maven-jar-plugin.

       <plugin>
           <!-- Build an executable JAR -->
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-jar-plugin</artifactId>
           <version>3.1.0</version>
           <configuration>
               <archive>
                   <manifest>
                       <addClasspath>true</addClasspath>
                       <classpathPrefix>lib/</classpathPrefix>
                       <mainClass>somePackage.sample</mainClass>
                   </manifest>
               </archive>
           </configuration>
       </plugin>
   

screen capture: 4. open maven project box by click on the search icon and type maven,

5. click on clean, then click on install

6. your jar file will show up inside the target folder

7. test your jar using java -jar

Method 2: Build jar with maven without pom.xml change

1. File, new, project, maven
2. create a package , create a java program inside that package (same as above)
3. File -> Project Structure -> Project Settings -> Artifacts -> Click green plus sign -> Jar -> From modules with dependencies

Very important!

The MANIFEST.MF needs to be in your resources folder and the Main.Class needs to refer to {package}-{class-name-that-contains-main-class}

4. then click build on menu , build artifacts, build

5. find the jar in the out folder

6. run it :)

Holy

this works. Can you explain why MANIFEST.MF needs to be in that directory? – Assuntaassur

This helps for me – Drynurse

This is very helpful! The second option worked best for me. Just a quick update: IntelliJ opens an extra wizard to create the manifest file. This will allow you to create it and place it in the right location without having to write anything. – Centennial

Thats very helpfull – Appreciation

Answer 6

When i use these solution this error coming:

java -jar xxxxx.jar

no main manifest attribute, in xxxxx.jar

and solution is:

You have to change manifest directory:

<project folder>\src\main\java 

change java to resources

<project folder>\src\main\resources

Oneirocritic

I already have this, but still have a problem – Tuckerbag

Answer 7

It is probably little bit late, but I managed to solve it this way -> open with winrar and delete ECLIPSEF.RSA and ECLIPSEF.SF in META-INF folder, moreover put "Main-class: main_class_name" (without ".class") in MANIFEST.MF. Make sure that you pressed "Enter" twice after the last line, otherwise it won't work.

Install

For signed dependencies, please have a look at this answer: #41746677 – Dermott

What an insane issue. Any idea why this happens or how to fix? This feels hacky – Floccus

Answer 8

I was trying to build a jar from a multi-module Kotlin app and was getting the notorious 'no main manifest attribute' error. Creating the manifest directory in src/main/resources didn't work either.

Instead, it works when creating it in src directly: src/META-INF/MANIFEST.MF.

Souvenir

Hi, Thanks it's working fine. But now I have a new error that it's not finding the resources "java.desktop/javax.swing.ImageIcon java.lang.NullPointerException" – Auster

Answer 9

As the people above says, but I have to note one point. You have to check the checkbox:

Include in project build

Dualism

Answer 10

Using

mvn clean package spring-boot:repackage

type above command inside IntelliJ Terminal. It generates a Target file with Executable Jar.

Sting

Answer 11

With Maven you can use this plugin:

 <build>
    <plugins>

        <plugin>
            <artifactId>maven-assembly-plugin</artifactId>
            <configuration>
                <archive>
                    <manifest>
                        <mainClass>[path you class main]</mainClass>
                    </manifest>
                </archive>
                <descriptorRefs>
                    <descriptorRef>jar-with-dependencies</descriptorRef>
                </descriptorRefs>
            </configuration>
            <executions>
                <execution>
                    <id>make-assembly</id>
                    <phase>package</phase> 
                    <goals>
                        <goal>single</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>

Slue

Answer 12

My problem was this: I used Intellij IDEA (tried different versions) + Gradle. When I compiled the project and builded artifacf jar, as indicated in the above responses, I received an error - "no main manifest attrubute ..."

This solution worked for me (special thanks to Thilina Ashen Gamage (see above) for tip):

Excerpt - if you use external libraries and build a project through Project Settings - Artifacts - Add (+) - Jar - From modules with dependencies, then probably because of a program bug the META-INF folder with MANIFEST_MF file not including to jar. To avoid it create EMPTY jar file.

Project Settings - Artifacts - Add (+) - Jar - EMPTY JAR. META-INF folder will added to resources folder. Then select your main class. You will see following jar structure: Note the presence of a folder META-INF Then you can build your project and build artifacts. This solution worked for javaFX applications too.

Yod

Answer 13

Here is the official answer of IntelliJ IDEA 2018.3 Help. I tried and It worked.

To build a JAR file from a module;

1. On the main menu, choose Build | Build Artifact.

2. From the drop-down list, select the desired artifact of the type JAR. The list shows all the artifacts configured for the current project. To have all the configured artifacts built, choose the Build all artifacts option.

Peak

Answer 14

Idea 8.1.3

Jar is ok, since there is compiled output in 'output' directory (project/out/production//)

I guess, you have to run 'make' before building jar

for dependencies just check "show library" and choose what you want.

Masoretic

Without gradle its working properly but when i build gradle based project in IntelliJIdea its show C:\Validate\out\artifacts\Validate_jar>java -jar Validate.jar Error: Could not find or load main class Validate Caused by: java.lang.ClassNotFoundException: Validate – Unravel

Answer 15

If you're using the new beta IntelliJ UI, the above solutions will require modification.

Currently, in the new beta IntelliJ UI, there is a bug where if you click on the "build" button in the build artifacts menu, nothing will happen.

However, if you use arrow keys to navigate to the "build" button, and then press "enter" on your keyboard, it will work.

or you can do the following:

You have to shift+shift type [Build Artifacts...] > then use arrow keys to navigate build artifact floating menu and hit enter.

Bug tracker: https://youtrack.jetbrains.com/issue/IDEA-316889/Build-artifacts-inactive-if-hamburger-menu-is-on

Hopefully this saves someone from the hour of pain I experienced trying to get my JAR file to be built.

Lenhart

Answer 16

I tried most of the given answers, but in my case "out" folder (which contains jar file) was not getting created. So this did the job :

Build -> Build Artifacts -> (you will see the class name) -> Build

Now, "out" folder was created and jar file was in it.

Goad

Answer 17

Use Gradle to build your project, then the jar is within the build file. Here is a Stack Overflow link on how to build .jar files with Gradle.

Java project with Gradle and building jar file in Intellij IDEA - how to?

Ozalid

Answer 18

In case you are reading this answer because you are facing "resource file not found" error, try this:

1. File -> Project Structure -> Artiface -> New, type is Other.
2. Give it a nice name, and in the Output Layout, press Create Archive to create a new jar, and again, give it a nice name ;)
3. Click on the jar you just added, add your compiled module output in the jar.
4. Click on the jar again, in the lower pane, select your project path and add Manifest File then set correct Main Class and Class Path.
5. Click Add Library Files, and select libraries you need (you can use Ctrl+A to select all).
6. Build -> Build Artifact -> Clean & Build and see if the error is gone.

Urbane

Answer 19

In case you are trying to build a jar with kotlin you need to create a src/main/java folder and use this folder as a location for the META-INF folder.

Sedlik

Answer 20

Some of the other answers are useless because as soon as you re-import the IntelliJ IDEA project from the maven project, all changes will be lost.

The building of the jar needs to be triggered by a run/debug configuration, not by the project settings.

Jetbrains has a nice description of how you can accomplish this here:

https://www.jetbrains.com/help/idea/maven.html

Scroll down to the section called "Configuring triggers for Maven goals".

(The only disadvantage of their description is that their screenshots are in the default black-on-white color scheme instead of the super-awesome darcula theme. Ugh!)

So, basically, what you do is that you open the "Maven Projects" panel, you find the project of interest, (in your case, the project that builds your jar,) underneath it you find the maven goal that you want to execute, (usually the "package" goal creates jars,) you open up the context menu on it, (right-click on a Windows machine,) and there will be an "Execute before Run/Debug..." option that you can select and it will take you by the hand from there. Really easy.

Hydrous

Answer 21

If you are using third party libraries with your project or if you have problems with creating MANIFEST.MF file properly, there can be conflicts when running JAR files generated using

File > Project Structure > Artifacts > '+' > JAR > From modules with dependencies > .....

method mentioned above.

Instead I suggest you to create an empty JAR and add all other elements to the output root manually. A wonderful blog article for this method can be found here: http://karthicraghupathi.com/2016/07/10/creating-an-executable-jar-in-intellij-idea/ I tried the steps mentioned there and everything worked fine for me!

Fractostratus

Thanks, this helped me! There appears to be a bug in Intellij where the manifest of the project is overwritten in the JAR by a default manifest if you select "JAR" as the artifact type instead of "Other". – Booklover

Answer 22

You might want to take a look at Maven (http://maven.apache.org). You can use it either as the main build process for your application, or just to perform certain tasks through the Edit Configurations dialog. The process of creating a JAR of a module within Maven is fairly trivial, if you want it to include all the dependencies in a self-executable JAR that is trivial as well.

If you've never used Maven before then you want to read Better Builds With Maven.

War

Maven is obviously overhead for a simple tasks like creating jar. Maybe Ant but not maven for sure. – Goldman

Link is dead (Oct 2014) – Maroney

@Maroney Thanks - updated to use the Maven team's recommendations. – War

If it's so trivial, why not include it in your answer? – Gelasius

Because I wish the reader to visit the site and begin the learning process. – War

Answer 23

If you are working on spring/mvn project you can use this command:

mvn package -DskipTests

The jar file will be saved on target directoy.

Utilize

Answer 24

Ant and Maven are widely used. I prefer Ant, I feel it's more lightweight and you the developer are more in control. Some would suggest that's its downside :-)

Arianearianie

This does nothing to explain why the error is happening. – Putandtake