What does mvn install in maven exactly do

Question

I just started using Maven and I was told to do mvn install in a specific directory.

What does mvn install do, exactly?

I think it looks for pom.xml in the current folder and starts following the instructions specified in that file. Is that correct?

http://maven.apache.org/guides/getting-started/maven-in-five-minutes.html — Michał Kalinowski, May 10 '12 at 12:22

score 156 · Accepted Answer · edited Oct 09 '19 at 13:15

As you might be aware of, Maven is a build automation tool provided by Apache which does more than dependency management. We can make it as a peer of Ant and Makefile which downloads all of the dependencies required.

On a mvn install, it frames a dependency tree based on the project configuration pom.xml on all the sub projects under the super pom.xml (the root POM) and downloads/compiles all the needed components in a directory called .m2 under the user's folder. These dependencies will have to be resolved for the project to be built without any errors, and mvn install is one utility that could download most of the dependencies.

Further, there are other utils within Maven like dependency:resolve which can be used separately in any specific cases. The build life cycle of the mvn is as below: LifeCycle Bindings

process-resources
compile
process-test-resources
test-compile
test
package
install
deploy

The test phase of this mvn can be ignored by using a flag -DskipTests=true.

Just a side note, if you want to skip all the test related goals, use: -Dmaven.test.skip=true (instead of -DskipTests=true) — Manoj Shrestha, May 31 '16 at 18:58
This answer fails to clarify that the install command ultimately *installs* the artifact locally, that is, in the local repository. — PCH, Jul 03 '20 at 18:07

score 41 · Answer 2 · answered May 10 '12 at 12:21

41

Have you looked at any of the Maven docs, for example, the maven install plugin docs?

Nutshell version: it will build the project and install it in your local repository.

answered May 10 '12 at 12:21

Dave Newton

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Let's say you run "mvn install" on an open-source library. Then, you run "mvn install" on a project that uses the open-source library that we first compiled. When running "mvn install", will JARs first be looked up in the local repo? Or is it dependent on the POM file? – Kevin Meredith Jun 19 '13 at 19:48
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@Kevin It should go local first, since that's kind of the point. If it's not in the local repository it will look in whatever repositories you have configured (or the defaults) and install it to your local repo if it's found. I suspect you could configure it to always skip the local repo, although I don't know how without looking it up. – Dave Newton Jun 19 '13 at 19:53
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Have *you* looked at the canonical documents for Maven? Apache's site explains the purpose of mvn install thus: "In most cases, install:install goal doesn't need any configuration, it needs the project's POM and the artifact file to be installed during the install phase of the default build lifecycle." It is because Apache's doc fails to explain what 'mvn install' actually does that people like the poster, and myself, are looking for the answer. Perfectly reasonable question. – bethesdaboys Jul 11 '13 at 11:15

score 9 · Answer 3 · answered Oct 26 '17 at 10:39

The install:install goal is provided by «Apache Maven Install Plugin»:

Apache Maven Install Plugin

The Install Plugin is used during the install phase to add artifact(s) to the local repository. The Install Plugin uses the information in the POM (groupId, artifactId, version) to determine the proper location for the artifact within the local repository.

The local repository is the local cache where all artifacts needed for the build are stored. By default, it is located within the user's home directory (~/.m2/repository) but the location can be configured in ~/.m2/settings.xml using the <localRepository> element.

— Apache Maven Install Plugin - Introduction.

Having said that, the exact goal purpose:

install:install is used to automatically install the project's main artifact (the JAR, WAR or EAR), its POM and any attached artifacts (sources, javadoc, etc) produced by a particular project.

— Apache Maven Install Plugin - Introduction.

For additional details on the goal, please refer to the Apache Maven Install Plugin - install:install page.

For additional details on the build lifecycle in general and on which place the goal has in the build lifecycle, please refer to the Maven – Introduction to the Build Lifecycle page.

score 8 · Answer 4 · answered May 10 '12 at 12:42

8

It will run all goals of all configured plugins associated with any phase of the default lifecycle up to the "install" phase:

https://maven.apache.org/guides/introduction/introduction-to-the-lifecycle.html#Lifecycle_Reference

answered May 10 '12 at 12:42

Puce

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score 8 · Answer 5 · edited Jun 20 '20 at 09:12

8

Short answer

mvn install

adds all artifact (dependencies) specified in pom, to the local repository (from remote sources).

edited Jun 20 '20 at 09:12

Community

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answered May 14 '19 at 13:55

Daniel Perník

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You forgot to mention that it also builds the project. – jurez Oct 01 '20 at 05:11

Jyoti Prakash · Answer 6 · 2023-03-11T19:39:01.797

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We have -DskipTests=true and -Dmaven.test.skip=true

"maven.test.skip.exec=true" the tests will be compiled, but will not executed.

"maven.test.skip=true" doesn't compile or execute the tests.

"-DskipTests" is the same as "maven.test.skip.exec=true"

Make changes in Setting.xml in your .m2 folder. You can use link to local repo so that the jars once downloaded should not be downloaded again and again.

<url>file://C:/Users/admin/.m2/repository</url>
 </repository>

edited Mar 11 '23 at 19:39

answered Apr 04 '13 at 06:36

Jyoti Prakash

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-Dmaven.test.skip=true does not compile the tests. However, -DskipTests=true does. Therefore, they are not the same. They are common in not running tests. – Aksoy Jan 20 '23 at 09:16

score 3 · Answer 7 · answered Oct 14 '20 at 17:55

3

At any stage of maven build life cycle, all the previous goals are performed.

Ex: mvn install will invoke mvn validate, mvn compile, mvn test, mvn package etc.

answered Oct 14 '20 at 17:55

obul

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score 3 · Answer 8 · answered Jan 29 '21 at 08:53

It's important to point out that install and install:install are different things, install is a phase, in which maven do more than just install current project modules artifacs to local repository, it check remote repository first. On the other hand, install:install is a goal, it just build your current project and install all it's artifacts to local repository (e.g. into the .m2 directory).

Aditya Rewari · Answer 9 · 2022-08-03T06:37:08.657

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mvn install primary jobs are to

1)Download The Dependencies

2)Build The Project

while job 1 is nowadays taken care by IDs like intellij (they download for any dependency at POM)

mvn install is majorly now used for job 2.

edited Aug 03 '22 at 06:37

answered Dec 03 '19 at 08:52

Aditya Rewari

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Dharmendrasinh Chudasama · Answer 10 · 2023-01-24T14:30:02.233

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In general we should use mvn package instead of mvn install, which mistake I have seen everywhere

Mvn install copy generated jar from target to .m2 repository, which may generate some problem for developer in future

After my 7+ years of experience I suggest developers to use mvn package insted of mvn install

edited Jan 24 '23 at 14:30

answered Jan 24 '23 at 14:23

Dharmendrasinh Chudasama

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What does mvn install in maven exactly do

10 Answers10

Apache Maven Install Plugin

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