Can't execute jar- file: "no main manifest attribute"

Question

I have installed an application, when I try to run it (it's an executable jar) nothing happens. When I run it from the commandline with:

java -jar "app.jar"

I get the following message:

no main manifest attribute, in "app.jar"

Normally, if I had created the program myself, I would have added a main class attribute to the manifest file. But in this case, since the file is from an application, i cannot do that. I also tried extracting the jar to see if I could find the main class, but there are to many classes and none of them has the word "main" in it's name. There must be a way to fix this because the program runs fine on other systems.

I know, but since I only have .class files I can't really see the methods. Or can I? — Ewoud, Mar 13 '12 at 18:42
You aren't really typing the quotes, are you? In any case, there are a number of ways to see methods, include using `javap`. You might want to un-jar it and look to see if there's actually no manifest, though. — Dave Newton, Mar 13 '12 at 19:37
Related: with dependencies: http://stackoverflow.com/a/23986765/360211 — weston, Sep 13 '15 at 07:37
what if I don't have main class as I am running the code using CommandLineJobRunner — Kamini, Jun 02 '17 at 14:01
I had this problem with a library that had worked previously, simply because I was missing execution declaration steps... — MrMesees, May 04 '18 at 00:36
Solution involves adding META-INF to resources directory and few other steps explained here https://www.youtube.com/watch?v=wPGSas_f0ts — abdul rashid, Jun 18 '20 at 15:22
I have a task called `buildRepackage` , I think this is what does the task but I can't make a jar to be runnable with the whole dependency. Do you know how they work together and how I can get this done for a spring boot application? — Dimitri Kopriwa, Aug 23 '20 at 15:01

score 1103 · Answer 1 · edited Mar 31 '21 at 03:16

1103

First, it's kind of weird, to see you run java -jar "app" and not java -jar app.jar

Second, to make a jar executable... you need to jar a file called META-INF/MANIFEST.MF

the file itself should have (at least) this one liner:

Main-Class: com.mypackage.MyClass

Where com.mypackage.MyClass is the class holding the public static void main(String[] args) entry point.

Note that there are several ways to get this done either with the CLI, Maven, Ant or Gradle:

For CLI, the following command will do: (tks @dvvrt)

jar cmvf META-INF/MANIFEST.MF <new-jar-filename>.jar  <files to include>

For Maven, something like the following snippet should do the trick. Note that this is only the plugin definition, not the full pom.xml:

Latest doc on this plugin: see https://maven.apache.org/plugins/maven-jar-plugin/

<build>
  <plugins>
    <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>com.mypackage.MyClass</mainClass>
          </manifest>
        </archive>
      </configuration>
    </plugin>
  </plugins>
</build>

(Pick a <version> appropriate to your project.)

For Ant, the snippet below should help:

<jar destfile="build/main/checksites.jar">
  <fileset dir="build/main/classes"/>
  <zipfileset includes="**/*.class" src="lib/main/some.jar"/>
  <manifest>
    <attribute name="Main-Class" value="com.acme.checksites.Main"/>
  </manifest>
</jar>

Credits Michael Niemand -

For Gradle:

plugins {
    id 'java'
}

jar {
    manifest {
        attributes(
                'Main-Class': 'com.mypackage.MyClass'
        )
    }
}

edited Mar 31 '21 at 03:16

Kobedi

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answered Mar 13 '12 at 18:27

Olivier Refalo

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In Ant its within the element – Michael Niemand Feb 15 '13 at 10:08
2

Thank you. Just wanted to add that you can copy dependencies to the lib folder using this: http://stackoverflow.com/a/996915/1121497. Since the classpath includes that `lib` folder then you only need to execute the jar with `java -jar myproject.jar` and it will find the dependencies. – Ferran Maylinch May 31 '14 at 09:56
5

HOW TO "jar a file called META-INF/MANIFEST.MF" ? I have a .jar on one hand and a .MF on the other, how do I link them together ? I put the manifest in the same folder as the .jar but it doesn't work I still got the problem ! – Wicelo Sep 02 '14 at 13:02
I think that's a different question - but a jar is actually a zip. Just use your best zip tool to add the file in the right location. – Olivier Refalo Sep 04 '14 at 03:06
4

@Wicelo To specify a specific MANIFEST.MF file while creating a jar file use the _m_ flag for jar. eg. `jar cmvf META-INF/MANIFEST.MF .jar ` – dvvrt Sep 23 '14 at 20:23
thank you, will edit my answer. Are you sure about this command? it looks weird: a file, a destination... then files again. – Olivier Refalo Sep 24 '14 at 13:54
*usually named as maven so prefix would be maven maven/ – user4321 May 03 '17 at 18:08
for those dealing with android studio. see @QED answer https://stackoverflow.com/a/37127374/2445763 – lasec0203 Oct 21 '17 at 00:30
Excellent detail, thanks so much! One Maven n00b note, simply doing a rebuild in your IDE (such as Intellij) won't build the exec JAR. You have to run `mvn clean install` or equivalent. – Shane May 31 '18 at 15:09
1

Note: For Maven, I already had a `maven-jar-plugin` item in the VSC-generated Maven file, so I just added the `` section to it. – Aaron Franke Jan 11 '19 at 04:37
For Maven the explanation above is precise! – adrian filipescu Aug 26 '19 at 16:58
The quotes around "app.jar" is most likely swallowed by the shell used. – Thorbjørn Ravn Andersen Dec 06 '19 at 13:32
1

Having tried the for-Maven suggestion, I wanted to report that this does not work; The `jar` created in this way now barfs with an _"Error: A JNI error has occurred, please check your installation and try again"_. [The answer by @CodeBrew](https://stackoverflow.com/a/27662742/5110545) otoh, resulted in a `*-jar-with-dependencies.jar` that did the job just nicely. – cueedee Mar 25 '20 at 10:38
I have a task called `buildRepackage` , I think this is what does the task but I can't make a jar to be runnable with the whole dependency. Do you know how they work together and how I can get this done for a spring boot application? – Dimitri Kopriwa Aug 23 '20 at 15:01

score 322 · Answer 2 · answered Mar 13 '12 at 18:27

322

That should have been java -jar app.jar instead of java -jar "app".

The -jar option only works if the JAR file is an executable JAR file, which means it must have a manifest file with a Main-Class attribute in it. See Packaging Programs in JAR Files to learn how to create an executable JAR.

If it's not an executable JAR, then you'll need to run the program with something like:

java -cp app.jar com.somepackage.SomeClass

where com.somepackage.SomeClass is the class that contains the main method to run the program. (What that class is depends on the program, it's impossible to tell from the information you've supplied).

answered Mar 13 '12 at 18:27

Jesper

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thanks for your reply, but your solution only works if I know the name of the class that contains the main method. And it was a typo... It was supposed to be "app.jar". But how do you explain why it runs on other systems by just double clicking the file? – Ewoud Mar 13 '12 at 18:45
If it is indeed an executable JAR, you can extract the manifest file (it's in the `META-INF` directory inside the JAR file). It should contain a `Main-Class` attribute that gives you the name of the main class. – Jesper Mar 14 '12 at 06:21
If it doesn run on one system, then that system maybe has a too old Java version. If the JAR is for example compiled with Java 7, then you can't run it on a system that has Java 6 or older. – Jesper Mar 14 '12 at 06:23
That's funny since the other system is running win7 and this pc with the problems runs win8. – Ewoud Mar 15 '12 at 17:42
Is Java officially supported on Windows 8? – Jesper Mar 16 '12 at 06:17
3

@Jesper Hello, what if eclipse is using the default package? Do I just put the class name? – Ogen Jul 18 '14 at 05:08
Yes, if the class is in the default package, then just specify the class name without a package name. However, it's good practice to always put your code in a package. – Jesper Jul 28 '14 at 11:52
Note that it is useful to use 7-zip to open the "app.jar" file to find main class. For example, I downloaded tcpmon-1.1.jar from the Google Code Archive. MainWindow.class is located in com/codegoogle/tcpmon. Thus cmd: "java -cp tcpmon-1.1.jar com.codegoogle.tcpmon.MainWindow" opended tcpmon main window in Windows 10. – Dan Randolph Jun 24 '16 at 02:38
@DanRandolph A JAR file is indeed a ZIP file, so you can open and inspect JAR files with programs like 7-Zip or any other tool that can read ZIP files. – Jesper Jun 24 '16 at 06:49
I did it to run a jar listed in a jnlp file (xml). I found the main-class xml tag and it's running fine now. – Ratata Tata Sep 05 '17 at 18:57

score 147 · Answer 3 · edited Jan 23 '17 at 05:46

147

Alternatively, you can use maven-assembly-plugin, as shown in the below example:

<plugin>
    <artifactId>maven-assembly-plugin</artifactId>
    <executions>
      <execution>
        <phase>package</phase>
        <goals>
          <goal>single</goal>
        </goals>
      </execution>
    </executions>
    <configuration>
      <archive>
        <manifest>
          <addClasspath>true</addClasspath>
          <mainClass>com.package.MainClass</mainClass>
        </manifest>
      </archive>
      <descriptorRefs>
        <descriptorRef>jar-with-dependencies</descriptorRef>
      </descriptorRefs>
    </configuration>
  </plugin>

In this example all the dependency jars as specified in section will be automatically included in your single jar. Note that jar-with-dependencies should be literally put as, not to be replaced with the jar file names you want to include.

edited Jan 23 '17 at 05:46

eis

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answered Dec 26 '14 at 22:44

CodeBrew

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Perfect, this works. It bundles all dependencies in to one jar, thus allowing you to compile/build a project and run it out of the box. – Paul Jul 26 '15 at 19:08
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In the context of the [shade plugin](https://maven.apache.org/plugins/maven-shade-plugin/index.html), one has to follow the help at [Executable JAR](https://maven.apache.org/plugins/maven-shade-plugin/examples/executable-jar.html). – koppor Sep 06 '17 at 08:40
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This with `maven-assembly-plugin` worked. `maven-jar-plugin` did not. – Martynas Jusevičius Dec 07 '18 at 21:25
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Note: put this code in your `pom.xml` file inside ` PUT IT HERE ` and then execute maven Package (in IDEA open maven sliding menu on the right, look for project > Lifecycle > package). Then your jar file will be in Target folder . Cheers! – Kirill Karmazin Dec 10 '18 at 12:10
I was really struggling with this issue...This works perfectly. Thanks! – jmojico Feb 01 '19 at 02:38
This worked together with using mvn clean package assembly:single – JOSE MANUEL RAMIREZ LEON Dec 19 '19 at 16:35
this should be the answer. – Banee Ishaque K Jul 15 '20 at 14:03

Sasanka Panguluri · Answer 4 · 2013-09-29T00:32:30.803

That is because Java cannot find the Main attribute in the MANIFEST.MF file. The Main attribute is necessary to tell java which class it should use as the application's entry point. Inside the jar file, the MANIFEST.MF file is located in META-INF folder. Wondering how you could look at what's inside a jar file? Open the jar file with WinRAR.

The main attribute inside the MANIFEST.MF looks like this:

Main-Class: <packagename>.<classname>

You get this "no main manifest attribute" error when this line is missing from the MANIFEST.MF file.

~~It's really a huge mess to specify this attribute inside the MANIFEST.MF file.~~

Update: I just found a really neat way to specify the Application's entry point in eclipse. When you say Export,

Select Jar and next 

[ give it a name in the next window ] and next

and next again

and you'll see " Select the class of the application entry point".

Just pick a class and Eclipse will automatically build a cool MANIFEST.MF for you.

enter image description here

score 44 · Answer 5 · answered Mar 23 '18 at 09:38

44

I had the same issue. by adding following lines to pom file made it work. The plugin will make sure the build process of your application with all necessary steps.

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
    </plugins>
</build>

answered Mar 23 '18 at 09:38

Naga Srinu Kapusetti

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worked perfectly, but consider adding the version as of April 2018 org.springframework.boot spring-boot-maven-plugin 2.0.1.RELEASE – Tenflex Apr 16 '18 at 17:32
Sorry but it's not a solution because he is not talking about Spring Boot, it's general problem with jar execution :) – LAMRIN TAWSRAS Jul 16 '18 at 12:59
Thanks a lot, this solved the problem for spring boot! – AleksandarT Dec 11 '19 at 17:20
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I am working on spring boot 2.2.0.Release. Unfortunately, this solution did not work for me. However, it works when you have referred from a `...` application in the pom.xml. My guess is, if we visit the `parent` application's pom.xml, we will get a clear idea. – tusar Feb 06 '20 at 23:18
I finally solved my issue with the custom `repackage-classifier`. Please visit https://docs.spring.io/spring-boot/docs/2.2.0.RELEASE/maven-plugin/examples/repackage-classifier.html – tusar Feb 06 '20 at 23:54

score 36 · Answer 6 · answered Aug 09 '16 at 16:51

36

I had this issue when creating a jar using IntelliJ IDEA. See this discussion.

What solved it for me was to re-create the jar artifact, choosing JAR > From modules with dependencies, but not accepting the default Directory for META-INF/MANIFEST.MF. Change it from -/src/main/java to -/src/main/resources.

Otherwise it was including a manifest file in the jar, but not the one in -/src/main/java that it should have.

answered Aug 09 '16 at 16:51

morningstar

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This worked for me with IDEA 14.1.6. I also added the build property for pom.xml but it had no effect. But your answer solved it, thank you. – lsrom Oct 30 '16 at 22:34
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Thanks for saving my desktop from getting dented by the pure frustration of nothing else working ;) Your link seems broken, but I can confirm that this works perfectly. Tested with IntelliJ IDEA 2018.2.5 (Community Edition) – Matthias Bö Nov 12 '18 at 13:42
confirmed that this works, even though i dont have a /resources directory – lxknvlk Oct 04 '19 at 16:37
broken link, did you mean `https://stackoverflow.com/questions/20952713/wrong-manifest-mf-in-intellij-idea-created-jar`? – Ben Sep 04 '20 at 08:12
This still solved it for me in 2020 – brickyyyy Dec 10 '20 at 08:06

score 31 · Answer 7 · answered Mar 01 '13 at 16:06

For maven, this is what solved it (for me, for a Veetle codebase on GitHub):

<build>
<plugins>
  <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-shade-plugin</artifactId>
    <version>2.0</version>
    <executions>
      <execution>
        <phase>package</phase>
        <goals>
          <goal>shade</goal>
        </goals>
        <configuration>
          <transformers>
            <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
              <mainClass>org.lazydevs.veetle.api.VeetleAPI</mainClass>
            </transformer>
          </transformers>
        </configuration>
      </execution>
    </executions>
  </plugin>
 </plugins>
</build>

Cheers...

I found this worked but I had to execute as `mvn package shade:shade` just running `mvn package` didn't trigger the shade plugin to run. — Raystorm, Nov 27 '17 at 17:56

score 31 · Answer 8 · answered May 10 '16 at 00:15

31

The Gradle answer is to add a jar/manifest/attributes setting like this:

apply plugin: 'java'

jar {
    manifest {
        attributes 'Main-Class': 'com.package.app.Class'
    }
}

answered May 10 '16 at 00:15

QED

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the simplest answer thus far. – lasec0203 Oct 21 '17 at 00:28
For the Gradle build script written on Kotlin see [this answer](https://stackoverflow.com/a/63767408/355438). – Lu55 Jan 15 '21 at 15:56

score 27 · Answer 9 · edited Jul 15 '14 at 03:09

27

Try this command to include the jar:

java -cp yourJarName.jar your.package..your.MainClass

edited Jul 15 '14 at 03:09

Eric Leschinski

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answered Aug 23 '13 at 07:31

Burhan ARAS

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One way is to include main class in pom.xml and use java -jar command, other one is to use java -cp command. – Gaurav Khare May 10 '16 at 10:56

score 17 · Answer 10 · answered Nov 23 '16 at 21:29

17

If using Maven, include following in the pom

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.4.2.RELEASE</version>
</parent>

<properties>
    <java.version>1.8</java.version>
</properties>

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
    </plugins>
</build>

answered Nov 23 '16 at 21:29

shuang

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Who said this was a Spring Boot project? – james.garriss Sep 12 '17 at 11:46
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@james.garriss well I would say, I came to this post searching for `no main manifest attribute` error but I am working on spring boot application so this answer helped me. I already knew how to create `META-INF/MANIFEST.MF` file, but not how to make spring-boot automatically handles it. – Vishrant Jan 17 '18 at 04:20
7

I don't see any reason for downvoting this answer. If you are not using `spring-boot` just ignore it. Stackoverflow also helps to build your own issue repository which you face while programming. – Vishrant Jan 17 '18 at 04:21
@Vishrant I don't know about others but I downvoted because this answer does not address the question as it was posed. It may have *just happened* to answer your question, but your question wasn't really what was asked. – Bane Mar 05 '18 at 22:40
@Bane sure. but the question can be taken in a broad sense and this answer applies to it and can help others in the sense when they will use spring boot. – Vishrant Mar 06 '18 at 02:10
@Vishrant I get that, but then why don't we just submit a million answers to this question regarding every possible tech that the user *could* use, which just happens to involve the original question, just in case? There are a bazillion frameworks out there; should we provide unique answers for every one? Or should we instead seek to answer the specific, actual question and allow people to extrapolate that answer to any specific use-case they are dealing with? At some point, too many answers is like having too many shopping-choices: overwhelmingly ineffective. – Bane Mar 07 '18 at 02:51
@Vishrant besides, the responder wasn't even very accurate in their answer... he literally said "if using maven, do this: {add spring boot}"... that's a pretty confusing answer... I think Maven is generic enough that providing an "if using Maven"-answer actually seems appropriate... but it does *NOT* follow that "if using Maven", then add this spring-boot thing... Boot is awesome, but it's pretty terrible advise to add it randomly to your project in an attempt to get past this one problem and the fact you *can* add Boot via Maven has literally no relationship to the problem. – Bane Mar 07 '18 at 02:54
@Vishrant Finally, the correct complement to "if using maven, then do this..." is this (and is not adding Boot!): ` org.apache.maven.plugins maven-jar-plugin 3.0.2 com.myPackage.MyClass ` – Bane Mar 07 '18 at 02:57
@Vishrant Regarding the "downvote", it's important to realize that on SO they aren't used to merely indicate "this is spam" but also to clarify answers the voter considers high- vs low-quality. When doing this, the voter actually sacrifices their reputation & takes a slight hit to do so. If they are willing to take that hit, they probably feel justified. I am not a coder just looking to make things work, but rather an architect striving for things to be 'best fit'. It's important to me to arrive-at/promote good decisions, not just ones that happen to work, and I am willing to take that hit. – Bane Mar 07 '18 at 03:05
sniping aside, does anyone know how to get spring boot to do this if you include the plugin but NOT the parent? – Rhubarb May 16 '21 at 12:06

score 16 · Answer 11 · answered Jan 25 '15 at 09:15

For me, none of the answers really helped - I had the manifest file in correct place, containing the Main-Class and everything. What tripped me over was this:

Warning: The text file from which you are creating the manifest must end with a new line or carriage return. The last line will not be parsed properly if it does not end with a new line or carriage return.

(source). Adding a newline at the end of the manifest fixed it.

Yury Finchenko · Answer 12 · 2020-04-19T18:34:34.087

The MAVEN problem is that its try to include the first MANIFEST.MF file from first library from dependencies instead of THE OUR OWN MANIFEST.MF WHEN YOU USE ARTIFACTS!.

Rename yourjar.jar to yourjar.zip
Open MANIFEST.MF file from META-INF\MANIFEST.MF
Copy the real MANIFEST.MF that already generate in your project by MAVEN That include somelike that:

Manifest-Version: 1.0 Main-Class: yourpacket.yourmainclass (for exmaple info.data.MainClass)
Replace the content of MANIFEST.MF from youjar.zip with it.
Rename yourjar.zip to yourjar.jar back.
Now java -jar yourjar.jar work perfectly.

OR!

Simple create you own MANIFEST.MF and:

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-jar-plugin</artifactId>
    <version>3.2.0</version>
    <configuration>
        <archive>
            <manifestFile> Your path like: src/main/resources/META-INF/MANIFEST.MF </manifestFile>
            <index>true</index>
                <manifest>
                    <addClasspath>true</addClasspath>
                </manifest>
        </archive>
    </configuration>
</plugin>

But if you use maven panel (or maven command line) you can force it to generate own manifest and include it into JAR file.

Add to the you pom.xml's build section this code:

<plugins>
    <plugin>

    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-assembly-plugin</artifactId>
    <version>3.2.0</version>
    <executions>
        <execution>
            <phase>package</phase>
            <goals>
                <goal>single</goal>
            </goals>
        </execution>
    </executions>

    <configuration>
        <descriptorRefs>
            <descriptorRef>jar-with-dependencies</descriptorRef>
        </descriptorRefs>

        <archive>

            <index>true</index>

            <manifest>
                <addClasspath>true</addClasspath>
                <mainClass> yourpacket.yourmainclass (for exmaple info.data.MainClass)</mainClass>
            </manifest>
            <manifestEntries>
                <mode>development</mode>
                <url>${project.url}</url>
            </manifestEntries>
        </archive>
    </configuration>
</plugin>

Open the MAVEN panel (in Intellij) and execute "Install". It will generate the MANIFEST file and compile property the JAR file with all dependencies into the "Target" folder. Also it will be installed to the local maven repository.

score 11 · Answer 13 · answered Apr 23 '17 at 14:46

11

I had the same issue today. My problem was solved my moving META-INF to the resources folder.

answered Apr 23 '17 at 14:46

MTA

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This worked for me too. Try it if you are using Jetbrains IntelliJ – NickSoft May 12 '19 at 20:04

score 10 · Answer 14 · answered Sep 01 '17 at 10:39

10

I got same error just now. If u're using gradle, just add next one in ur gradle.build:

apply plugin: 'java'

jar {
    manifest {
        attributes 'Main-Class': 'com.company.project.MainClass'
    }
}

Where com.company.project.MainClass path to ur class with public static void main(String[] args) method.

answered Sep 01 '17 at 10:39

Binakot

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This helped me! gradle tutorials had specified using the top-level `mainClassName` variable set, but that only helps with `gradle run` command, not with creating an executable .jar – kevlarr Dec 11 '17 at 03:37

John M · Answer 15 · 2019-08-01T14:42:26.370

8

If the jar isn't following the rules, it's not an executable jar.

edited Aug 01 '19 at 14:42

answered Mar 13 '12 at 18:24

John M

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+1 for the Jar File Specification link (http://docs.oracle.com/javase/1.4.2/docs/guide/jar/jar.html) – Paolo Apr 06 '13 at 13:59

score 5 · Answer 16 · answered Feb 26 '16 at 00:02

I faced the same issue and it's fixed now:) Just follow the below steps and the error could be for anything, but the below steps makes the process smoother. I spend lot of time to find the fix.

1.Try restart the Eclipse (if you are using Eclipse to built JAR file) --> Actually this helped my issue in exporting the JAR file properly.

2.After eclipse restart, try to see if your eclipse is able to recognize the main class/method by your Java project --> right click --> Run as --> Run configurations --> Main --> click Search button to see if your eclipse is able to lookup for your main class in the JAR file. --> This is for the validation that JAR file will have the entry point to the main class.

After this, export your Java Dynamic project as "Runnable JAR" file and not JAR file.
In Java launch configuration, choose your main class.
Once export the jar file, use the below command to execute. java -cp [Your JAR].jar [complete package].MainClass eg: java -cp AppleTCRuleAudit.jar com.apple.tcruleaudit.classes.TCRuleAudit
You might face the unsupported java version error. the fix is to change the java_home in your shell bash profile to match the java version used to compile the project in eclipse.

Hope this helps! Kindly let me know if you still have any issues.

score 5 · Answer 17 · answered Nov 20 '16 at 01:00

If you are using the command line to assemble .jar it is possible to point to the main without adding Manifest file. Example:

jar cfve app.jar TheNameOfClassWithMainMethod *.class

(param "e" does that: TheNameOfClassWithMainMethod is a name of the class with the method main() and app.jar - name of executable .jar and *.class - just all classes files to assemble)

CodeMonkey · Answer 18 · 2017-01-20T07:00:39.300

I had the same problem. A lot of the solutions mentioned here didn't give me the whole picture, so I'll try to give you a summary of how to pack jar files from the command line.

If you want to have your .class files in packages, add the package in the beginning of the .java.

Test.java
```
package testpackage;

public class Test
{
    ...
}
```
To compile your code with your .class files ending up with the structure given by the package name use:
```
javac -d . Test.java
```
The -d . makes the compiler create the directory structure you want.
When packaging the .jar file, you need to instruct the jar routine on how to pack it. Here we use the option set cvfeP. This is to keep the package structure (option P), specify the entry point so that the manifest file contains meaningful information (option e). Option f lets you specify the file name, option c creates an archive and option v sets the output to verbose. The important things to note here are P and e.

Then comes the name of the jar we want test.jar.

Then comes the entry point .

And then comes -C . <packagename>/ to get the class files from that folder, preserving the folder structure.
```
jar cvfeP test.jar testpackage.Test -C . testpackage/
```
Check your .jar file in a zip program. It should have the following structure

test.jar
```
META-INF
| MANIFEST.MF
testpackage
| Test.class
```
The MANIFEST.MF should contain the following
```
Manifest-Version: 1.0
Created-By: <JDK Version> (Oracle Corporation)
Main-Class: testpackage.Test
```
If you edit your manifest by hand be sure to keep the newline at the end otherwise java doesn't recognize it.
Execute your .jar file with
```
java -jar test.jar
```

The 4th step of your answer is very important ! My manifest wasn't working because of that newline at the end I did not know I had to put. All answers I visited on this topic (a lot) did not mention this, and it is mandatory for anyone not using maven,ant,gradle, and so on. — Maude, Aug 21 '18 at 18:26
@Maude thank you for the feedback. That's precisely why I added the answer with the newline hint in **bold**. I looked for days until I found this out by comparing with an auto-generated manifest. — CodeMonkey, Aug 22 '18 at 15:05
Hah, thanks. I was just banging my head on that newline thing. — Richard Thomas, Jan 17 '20 at 21:12

score 5 · Answer 19 · answered Oct 27 '17 at 18:37

I personally think all the answers here are mis-understanding the question. The answer to this lies in the difference of how spring-boot builds the .jar. Everyone knows that Spring Boot sets up a manifest like this, which varies from everyones asssumption that this is a standard .jar launch, which it may or may not be :

Start-Class: com.myco.eventlogging.MyService
Spring-Boot-Classes: BOOT-INF/classes/
Spring-Boot-Lib: BOOT-INF/lib/
Spring-Boot-Version: 1.4.0.RELEASE
Created-By: Apache Maven 3.3.9
Build-Jdk: 1.8.0_131
Main-Class: org.springframework.boot.loader.JarLauncher

Perhaps it needs to executed with org.springframework.boot.loader.JarLauncher on the classpath?

This sounds promising. How exactly do you add JarLauncher to the classpath? — MarkHu, Feb 03 '18 at 06:01

score 4 · Answer 20 · answered Aug 03 '12 at 14:04

Any executable jar file Should run either by clicking or running using command prompt like java -jar app.jar (use "if path of jar contains space" - i.e. java -jar "C:\folder name\app.jar"). If your executable jar is not running, which means it is not created properly.

For better understanding, extract the jar file (or view using any tool, for windows 7-Zip is nice one) and check the file under /META-INF/MANIFEST.MF. If you find any entry like

Main-Class: your.package.name.ClaaswithMain - then it's fine, otherwise you have to provide it.

Be aware of appending Main-Class entry on MANIFEST.MF file, check where you are saving it!

score 4 · Answer 21 · edited May 29 '15 at 21:10

4

You might not have created the jar file properly:

ex: missing option m in jar creation

The following works:

jar -cvfm MyJar.jar Manifest.txt *.class

edited May 29 '15 at 21:10

kenorb

118,428
63
588
624

answered Aug 28 '13 at 17:59

satheesh.v

49
1

score 4 · Answer 22 · answered Sep 28 '13 at 04:59

4

You Can Simply follow this step Create a jar file using

 jar -cfm jarfile-name manifest-filename Class-file name

While running the jar file simple run like this

 java -cp jarfile-name main-classname

answered Sep 28 '13 at 04:59

Koneri

287
2
10
27

score 3 · Answer 23 · answered Nov 27 '15 at 06:38

3

For me this error occurred simply because I forgot tell Eclipse that I wanted a runnable jar file and not a simple library jar file. So when you create the jar file in Eclipse make sure that you click the right radio button

answered Nov 27 '15 at 06:38

Neeraj Bhatnagar

181
1
1
6

score 3 · Answer 24 · answered Apr 21 '17 at 21:11

The above answers were only partly helpful for me. java -cp was part of the answer, but I needed more specific info on how to identify the class to run. Here is what worked for me:

Step 1: find the class I need to run

jar tf /path/to/myjar.jar | more

The top lines of the result were:

META-INF/
META-INF/MANIFEST.MF
somepath/
somepath/App.class
META-INF/maven/
...

App.class contained the main class to run. I'm not 100% sure if you can always assume the class you need is the first one, but it was for me. If it isn't, I'd imagine it isn't too hard to use grep to exclude library-related results to pare the class list down to a manageable size.

From there it was easy: I just use that path (minus the ".class" suffix):

java -cp /path/to/myjar.jar somepath/App

It isn't always the first class. Hardly ever. Command line should be `java -cp ... somepackage.App`. — user207421, Mar 06 '18 at 02:16

score 3 · Answer 25 · answered Jan 09 '18 at 17:29

I found a new solution to bad manifest generation !

Open the jar file with a zip editor like WinRAR
Click on for META-INF
Add or edit
- Add:
  - Create a text file called MANIFEST.MF in a folder called META-INF and add the following line:
    - Manifest-Version: 1.0
    - Main-Class: package.ex.com.views.mainClassName
  - Save the file and add it to the zip
- Edit:
  - Drag the file out modify the MANIFEST.MF to add the previous line
Open cmd and type: java -jar c:/path/JarName.jar

It should work fine now !

score 2 · Answer 26 · answered Mar 22 '17 at 09:47

Since you've add MANIFEST.MF, I think you should consider the order of Field in this file. My env is java version "1.8.0_91"

and my MANIFEST.MF as here

// MANIFEST.MF
Manifest-Version: 1.0
Created-By: 1.8.0_91 (Oracle Corporation)
Main-Class: HelloWorldSwing

// run
~ java -jar HelloWorldSwing.jar
no main manifest attribute, in HelloWorldSwing.jar

However, this as below run through

Manifest-Version: 1.0
Main-Class: HelloWorldSwing
Created-By: 1.8.0_91 (Oracle Corporation)

//this run swing normally

Eh? The order is immaterial. Unclear what you're claiming. – user207421 Mar 06 '18 at 02:19 — user207421, Mar 06 '18 at 02:19

score 2 · Answer 27 · answered Jun 19 '17 at 19:52

(first post - so it may not be clean)

This is my fix for OS X 11.6, Maven-based Netbeans 8.2 program. Up to now my app is 100% Netbeans - no tweaking (just a few shell escapes for the impossible!).

Having tried most all of the answers here and elsewhere to no avail, I returned to the art of "use what works".

The top answer here (olivier-refalo thanx) looked like the right place to start but didn't help.

Looking at other projects which did work, I noticed some minor differences in the manifest lines:

addClasspath, classpathPrefix were absent (deleted them)
mainClass was missing the "com." (used the NB -> Project Properties->Run->Main Class->Browse to specify)

Not sure why (I am only 3 months into java) or how, but can only say this worked.

Here is just the modified manifest block used:

    <manifest>
        <mainClass>mypackage.MyClass</mainClass>
    </manifest>

score 2 · Answer 28 · answered Sep 22 '17 at 22:37

2

Just to make one point clear about

Main-Class: <packagename>.<classname>

If you don't have package you have to ignore that part, like this:

Main-Class: <classname>

answered Sep 22 '17 at 22:37

Reihan_amn

2,379
2
16
17

Is there anything wrong here that I am getting down vote?! – Reihan_amn May 11 '18 at 06:19

score 2 · Answer 29 · answered Feb 04 '20 at 05:26

I tried this and it worked for me. mvn clean install package should work.

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
            <executions>
            <execution>
                <goals>
                    <goal>repackage</goal>
                </goals>
            </execution>
            </executions>
        </plugin>
    </plugins>
</build>

score 2 · Answer 30 · edited Feb 26 '21 at 07:34

For my case the problem is <pluginManagement> under <build> makes things cannot work properly.

My original pom.xml:

<build>
  <pluginManagement>
    <plugins>
      <plugin>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-maven-plugin</artifactId>
        ...
        ...
        ...
  </pluginManagement>
</build>

After removing <pluginManagement>, the error is gone.

RaminS · Answer 31 · 2015-11-17T22:20:42.847

You might have the same problem as I do. After creating your .jar file, write jar xf app.jar META-INF/MANIFEST.MF. This will create a copy of the file to your current directory so you can read it. If it only says something like:

Manifest-Version: 1.0

Created-By: 1.8.0_51 (Oracle Corporation)

and does not contain the "Main-Class" declaration, then I think you found your problem.

I do not know how to solve it, though. I checked other people with same/similar problems on StackOverflow and couldn't find an answer. However with this information you can perhaps get some better help (given the fact that you have the same problem as I).

Edit: I had tried with a manifest-file but didn't get it to work, but my mistake was to only name one of the classes when creating the jar-file. I wrote *.class instead and it works now.

Although I don't know why there is a need to create a manifest-file. But I guess it's fine as long as it works.

Abdelsalam Shahlol · Answer 32 · 2017-09-04T15:49:59.143

1

I had this problem and i solved it recently by doing this in Netbeans 8 (Refer to the image below):

Netbeans project properties

go to properties of your project.
click on Run.
specify the main class of your project using browse.
build and run the Jar file.

edited Sep 04 '17 at 15:49

answered Feb 01 '17 at 05:45

Abdelsalam Shahlol

1,171
1
17
26

score 1 · Answer 33 · answered Mar 15 '19 at 05:09

Found a great solution which would help in any such situation, given you just need a runnable jar, which you do in most cases. If your application is running in Intellij Idea follow these steps: 1) Go to module settings and then artifacts, and add a jar and define main class 2) Then go to Build in the menu and click "build artifact" and you get the jar.

This worked even when I changed the source folder and used scala instead of java.

score 1 · Answer 34 · answered Jun 18 '19 at 18:23

most of the solutions did not work for me but my instructor helped me out i would like to share his solution here i used kali linux terminal but should be fine in all debian

javac *.java
nano MANIFEST.MF

in the file type

Main-Class: Main or whatever your main file name is (make sure to add package name if it exists)

jar -cvmf MANIFEST.MF new.jar *.class

now to run the file use

java -jar new.jar

or you can go to propeties of file and check

Allow Execution of file as program

double click on it

it helped me while most of the above answers did not

score 1 · Answer 35 · answered Nov 27 '19 at 05:18

I was getting the same error when executing mvn package. This is how I solved the problem.

I was using the maven-multi-module. I was facing this issue because I added below part in parent pom by mistake.

<plugin>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-maven-plugin</artifactId>
</plugin>

Then after adding this in submodules pom.xml and removing from parent pom solved my problem.

score 1 · Answer 36 · answered May 12 '21 at 09:50

In my case - I work on a multi-module project - I could introduced the issue in the following way:

I added this into the parent pom.xml, which caused the issue. Namely, the skip with value true:

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
            <configuration>
                <!--
                besides hindering the packaging, this also skips running the app after build when calling spring-boot:run. You have to enable it in the
                corresponding module by setting skip to false, there.
                -->
                <skip>true</skip>
            </configuration>
        </plugin>
    </plugins>
</build>

I fixed the issue by adding the same configuration to the modules that i wanted to be packaged as a jar, but changed the value of skip to false:

<plugin>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-maven-plugin</artifactId>
    <version>${spring-boot.version}</version>
    <configuration>
        <mainClass>${project.mainClass}</mainClass>
        <layout>ZIP</layout>
        <skip>false</skip>
    </configuration>
    <executions>
        <execution>
            <goals>
                <goal>repackage</goal>
            </goals>
        </execution>
        <execution>
            <id>build-info</id>
            <goals>
                <goal>build-info</goal>
            </goals>
        </execution>
    </executions>
</plugin>

score 0 · Answer 37 · answered Dec 04 '16 at 00:52

check your jar file inside MANIFEST.MF Main-Class is available or not

first.java

class first
{
        public static void main (String arg[ ])
        {
           System.out.println("Welcome to the world of Java");
        }
}

Before:

Manifest-Version: 1.0
Created-By: 1.7.0_80 (Oracle Corporation)

sony@sony-VPCEH25EN:~/Documents$ java -jar first.jar
no main manifest attribute, in first.jar

After:

Manifest-Version: 1.0
Created-By: 1.7.0_80 (Oracle Corporation)
Main-Class: first

sony@sony-VPCEH25EN:~/Documents$ java -jar first.jar 
Welcome to the world of Java

M.87 · Answer 38 · 2016-12-28T13:20:33.447

I had a similar issue as you, in below a syntax to create successfully .war File:-

jar {cvf} [jar-file] [manifest-file]

manifest When creating (c) or updating (u) a JAR file, the manifest operand defines the preexisting manifest files with names and values of attributes to be included in MANIFEST.MF in the JAR file. The manifest operand must be specified if the f option is present '[1]'.

In order to create manifest file you need to defined a value for some attributes, you could put asterisk after the (.WAR) file name to avoid creating manifest file:-

jar -cvf foo.war *

To be honest with you I don't know if that is a best practice but it do the work for me :).

score 0 · Answer 39 · answered Jul 06 '20 at 22:21

0

Create the folder META-INF and the file MANIFEST.MF in that folder with this content:

Manifest-Version: 1.0
Class-Path: .
Main-Class: [YOUR_MAIN_CLASS]

Then compile including that manifest file.

answered Jul 06 '20 at 22:21

Lumito

427
4
17

score 0 · Answer 40 · answered Jul 22 '20 at 12:54

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

jar {
  manifest { 
    attributes "Main-Class": "com.company.application.Main"
  }  

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

This will result in [module_name]/build/libs/[module_name].jar file. I tested this with shell.

score 0 · Answer 41 · answered Mar 08 '21 at 11:03

If your on maven and your pom.xml is something like this

    <?xml version="1.0" encoding="UTF-8"?>
    <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
      <modelVersion>4.0.0</modelVersion>
      <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.4.3</version>
        <relativePath/> <!-- lookup parent from repository -->
      </parent>
      <groupId>com.example</groupId>
      <artifactId>demo</artifactId>
      <version>0.0.1-SNAPSHOT</version>
      <name>demo</name>
      <properties>
        <java.version>11</java.version>
      </properties>
      <dependencies>
        <!-- dependencies -->
      </dependencies>
      <build>
        <pluginManagement>
          <plugins>
            <plugin>
              <groupId>org.springframework.boot</groupId>
              <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
          </plugins>
        </pluginManagement>
      </build>
    </project>

just comment the pluginManagement that will result you in the following pom.xml

    <?xml version="1.0" encoding="UTF-8"?>
    <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
      <modelVersion>4.0.0</modelVersion>
      <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.4.3</version>
        <relativePath/> <!-- lookup parent from repository -->
      </parent>
      <groupId>com.example</groupId>
      <artifactId>demo</artifactId>
      <version>0.0.1-SNAPSHOT</version>
      <name>demo</name>
      <properties>
        <java.version>11</java.version>
      </properties>
      <dependencies>
        <!-- dependencies -->
      </dependencies>
      <build>
        <plugins>
          <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
          </plugin>
        </plugins>
      </build>
    </project>

score -1 · Answer 42 · answered Jul 05 '16 at 14:02

-1

Check your local .m2 direcory for a sub directory of this artifact. If exixts - delete it, and perform Maven update again

answered Jul 05 '16 at 14:02

dushkin

1,541
1
19
48

Can't execute jar- file: "no main manifest attribute"

42 Answers42

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