mvn package → Doesn’t install locally vs mvn install → Installs locally

This is another concept that confuses many developers. Let’s make it crystal clear.

When people say:

• mvn package → Doesn’t install locally
• mvn install → Installs locally

they are NOT talking about installing the application on your computer.

They mean installing the artifact into Maven’s Local Repository (.m2/repository).

---

First understand the two locations

After building a project, there are two possible places where the JAR can exist.

Location 1 – Project’s target folder

Order-Service/
│
├── src/
├── pom.xml
└── target/
      └── order-service-1.0.jar

This JAR belongs only to this project.

---

Location 2 – Maven Local Repository

C:\Users\Prakash\.m2\repository

or

~/.m2/repository

Example

.m2/
   repository/
      com/
         company/
             order-service/
                 1.0/
                    order-service-1.0.jar

This JAR can now be used by any Maven project on your machine.

---

What happens with mvn package?

Suppose you execute

mvn package

Flow

Compile
      ↓
Test
      ↓
Package

Result

Order-Service/

target/

order-service-1.0.jar

Notice

.m2/

repository/

does NOT get updated.

The JAR only exists inside your project.

Think of it like this:

Order-Service

↓

Own Locker

↓

target/

Nobody else can automatically use it.

---

What happens with mvn install?

Now execute

mvn install

Flow

Compile

↓

Test

↓

Package

↓

Install

Now Maven does

Step 1

Creates

target/order-service.jar

Exactly like package.

Step 2

Copies

target/order-service.jar

↓

to

~/.m2/repository/

Now there are two copies.

Project

target/

order-service.jar

AND

.m2/

repository/

order-service.jar

---

Why is .m2 important?

Imagine you have two projects.

Order-Service

and

Payment-Service

Payment-Service needs Order-Service.

In pom.xml

<dependency>
    <groupId>com.company</groupId>
    <artifactId>order-service</artifactId>
    <version>1.0</version>
</dependency>

Now when Maven builds Payment-Service,

it searches

1. Local Repository (.m2)

↓

2. Remote Repository (Maven Central)

If it finds

order-service.jar

inside .m2

it immediately uses it.

Without mvn install, Maven won’t find your locally built artifact unless it’s available from a remote repository.

---

Real Company Example

Suppose your company has

Common-Library

Order-Service

Payment-Service

Both services depend on

Common-Library

You modify

Common-Library

Now execute

mvn install

Result

Common-Library.jar

↓

.m2/repository

Now

Order-Service

and

Payment-Service

can immediately use the latest version.

No manual copying.

No uploading.

---

Why is it called “Install”?

Think of it like installing software.

When you install Chrome,

it is copied from

Downloads

↓

to

Program Files

Similarly

target/order-service.jar

↓

is copied into

.m2/repository

So Maven says

“The artifact has been installed into the local repository.”

---

Visual Comparison

mvn package

Write Code
      │
      ▼
Compile
      │
      ▼
Package
      │
      ▼
target/order-service.jar

Done

Only one copy.

---

mvn install

Write Code
      │
      ▼
Compile
      │
      ▼
Package
      │
      ▼
target/order-service.jar
      │
      ▼
Copy JAR
      │
      ▼
~/.m2/repository/order-service.jar

Two copies.

Interview Question

What does “Installs locally” mean in Maven?

“Installing locally means Maven copies the generated artifact (JAR or WAR) from the project’s target directory into the local Maven repository (~/.m2/repository). This makes the artifact available as a dependency for other Maven projects on the same machine. It does not mean installing or running the application on the operating system.”

---

Easy Memory Trick

Think of it like this:

mvn package

↓

Makes the JAR

mvn install

↓

Makes the JAR

+

Registers it in Maven's local repository

One-line interview answer

• mvn package → “Build my application.”
• mvn install → “Build my application and make it available to other local Maven projects by copying it into the local Maven repository (.m2/repository).”