Eclipse showing "Maven Configuration Problem: Unknown"

Question

I just imported a spingboot project that I created in https://start.spring.io/ in eclipse. I tried to import two times, but the problem persists. Already tried to do a mvn update , a mvn clean install, tried to clean the project but none of this worked. Its a problem in the first line of pom xml file. I dont have any idea how to solve this. I'm using java 11

error

This is the complete POM file:

<?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 
http://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>2.1.5.RELEASE</version>
    <relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.in28minutes.springboot.rest.example</groupId>
<artifactId>spring-boot-2-jpa-with-hibernate-and-h2</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>spring-boot-2-jpa-with-hibernate-and-h2</name>
<description>Demo project for Spring Boot</description>

<properties>
    <java.version>11</java.version>
</properties>

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>com.h2database</groupId>
        <artifactId>h2</artifactId>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <optional>true</optional>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
</dependencies>

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

I ran into this same problem, it was [Bug 547340 - Cannot import any project into Eclipse with maven-jar-plugin 3.1.2](https://bugs.eclipse.org/bugs/show_bug.cgi?id=547340). SOLUTION: `Eclipse > Help > Install New Software > Work with= https://download.eclipse.org/m2e-wtp/signed/mavenarchiver/0.17.4/, , m2e extensions= Y > Next...` Updating m2e did *NOT* work. Manually installing m2e 0.17.4 *DID* work. — paulsm4, Oct 21 '19 at 03:24

gybandi · Accepted Answer · 2019-05-22T16:51:25.547

This seems like a bug in eclipse: https://bugs.eclipse.org/bugs/show_bug.cgi?id=547340

You can fix this by temporary downgrading the maven jar plugin version to 3.1.1 from 3.1.2. Add this to the properties section:

<maven-jar-plugin.version>3.1.1</maven-jar-plugin.version>

So your pom will look 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 
http://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>2.1.5.RELEASE</version>
    <relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.in28minutes.springboot.rest.example</groupId>
<artifactId>spring-boot-2-jpa-with-hibernate-and-h2</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>spring-boot-2-jpa-with-hibernate-and-h2</name>
<description>Demo project for Spring Boot</description>

<properties>
    <java.version>11</java.version>
    <maven-jar-plugin.version>3.1.1</maven-jar-plugin.version>
</properties>

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>com.h2database</groupId>
        <artifactId>h2</artifactId>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <optional>true</optional>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
</dependencies>

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

Update: A fix has been released. Click Help > Check for updates in Eclipse/STS and install the newest m2e connector.

@RomuloSorato no problem ;) I also use eclipse, so I created a dummy project to reproduce the issue, after creation I immediatly encountered the issue. Tried maven build and application run, it worked flawlessly, so I concluded it could be a bug in eclipse. I did a search for 'maven' in the eclipse bugzilla and found an issue that seemed similiar — gybandi, May 22 '19 at 07:51
No luck with the 'update' to m2e, running latest downloadable eclipse, with the m2e milestone 1.12.0.20190529-1915, and it still does't work — bluemind, Jun 17 '19 at 13:44
Ah, it's the m2e-wtp, updating from this milestones download site made it work http://download.eclipse.org/m2e-wtp/milestones/1.4. You might want to add that in big letters :) — bluemind, Jun 17 '19 at 14:00

Romil Patel · Answer 2 · 2019-08-01T03:41:30.443

14

Step 1:

Downgrade to <maven-jar-plugin.version>3.1.1</maven-jar-plugin.version>

<properties>
    <java.version>X</java.version>
    <maven-jar-plugin.version>3.1.1</maven-jar-plugin.version>
</properties>

Step 2 Update Project

Right Click on your Project
Go to Maven
Click on Update Project
Clean and Re-Run your Application

edited Aug 01 '19 at 03:41

answered May 20 '19 at 04:55

Romil Patel

12,879
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2

The application runs fine,however, the error in line 1 persists – Rômulo Sorato May 20 '19 at 06:14
1

Do *NOT* downgrade anything. Eclipse "update" didn't help me, either. Instead, manually install the fix for Eclipse Bug 547340: `Eclipse > Help > Install New Software > Work with= https://download.eclipse.org/m2e-wtp/signed/mavenarchiver/0.17.4/, , m2e extensions= Y > Next...` – paulsm4 Oct 21 '19 at 03:31

Tanmay Naik · Answer 3 · 2019-06-27T10:12:22.163

7

<maven-jar-plugin.version>3.1.1</maven-jar-plugin.version>

Add this dependency in pom.xml under properties tag

edited Jun 27 '19 at 10:12

answered Jun 27 '19 at 10:02

Tanmay Naik

586
1
4
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score 4 · Answer 4 · edited Apr 02 '20 at 20:03

4

For spring boot project I have added this:

<properties>
            <java.version>1.8</java.version>
            <maven-jar-plugin.version>3.1.1</maven-jar-plugin.version>
        </properties>

edited Apr 02 '20 at 20:03

double-beep

5,031
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answered Apr 02 '20 at 03:55

Avinash Khadsan

441
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While this code may solve the question, [including an explanation](//meta.stackexchange.com/q/114762) of how and why this solves the problem would really help to improve the quality of your post, and probably result in more up-votes. Remember that you are answering the question for readers in the future, not just the person asking now. Please [edit] your answer to add explanations and give an indication of what limitations and assumptions apply. [From Review](/review/low-quality-posts/25753230) – double-beep Apr 02 '20 at 20:03

score 2 · Answer 5 · answered Jun 11 '19 at 11:15

2

Was Getting exact same error. Solution by Gybandi kinda worked for me.

Updating project in Maven> menu does nothing to make error icon go away.
Did the 3.1.1 and then did a maven -> update project from context menu. The red (x) icon is now GONE :-). But I really don't want to downgrade my maven plugin, if possible.
The suggestion of updating m2e-connector from eclipse marketplace does not work. All I see against the m2e-connector entry is a "learn more" link which takes me to its webpage. Nothing like "upgrade/update" button present.

answered Jun 11 '19 at 11:15

G.A.

1,443
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you could also try Help > Install new software, select "All Available sites" from "Work with" combobox and type in m2e in search, then check in the "m2e connector for mavenarchiver pom properties" under m2e extensions – gybandi Jun 12 '19 at 14:22
@gybandi thanks! Sadly I have the same problem as G.A.. Of course downgrading to v3.1.1 worked, but I would like not to have to do that. Now when I try to check for updates, it says there are none. Trying to get it from the Eclipse Market does not get me further either. I am using Eclipse Version: 2019-03 (4.11.0), Build id: 20190314-1200. I'll give Eclipse 2019-06 RC1 since I have some time on my hands. – Igor Jun 14 '19 at 21:59
@Igor have you tried "Install new software" section instead of the Eclipse Marketplace/Check for updates? Sometimes marketplace does not work for me neither – gybandi Jun 16 '19 at 07:26
@gybandi I actually did not try the Marketplace - just "Install New Software" from the Help-menu... weird... No proxy (since it was from my home PC) either... – Igor Jun 17 '19 at 12:41

score 2 · Answer 6 · answered Jul 12 '19 at 08:47

2

if you are using spring boot downgrade the version to 2.1.4.RELEASE instead of 2.1.5.RELEASE it will solve the problem

answered Jul 12 '19 at 08:47

Khaled Jamal

628
1
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Ravikiran butti · Answer 7 · 2019-12-03T11:38:39.813

I am using eclipse photon and had similar issue. Didnt want to add the maven-jar-plugin.version in my pom as I dont want my codebase to contain code specific to IDE.

What I noticed is eclipse photon has m2e version of 1.5 which is causing the problem. I uninstall all the m2e connectors, restarted my eclipse and then installed the m2e connector using the below url manually

https://download.eclipse.org/technology/m2e/releases/1.13/

this worked like a charm

score 2 · Answer 8 · answered Jan 05 '20 at 07:00

Adding packaging tag solved my problem. Didn't need to lower maven-jar plugin version.

<modelVersion>4.0.0</modelVersion>
<packaging>war</packaging>
<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.2.2.RELEASE</version>
    <relativePath/>
</parent>

score 0 · Answer 9 · answered Aug 06 '19 at 17:37

I fixed this issue by changing the version from 2.1.6 to 2.1.3

<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.3.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>

I changed this to 2.1.3 because there were two versions were shown available in local m2 repository at below path

.m2\repository\org\springframework\boot\spring-boot-starter-parent

Eclipse showing "Maven Configuration Problem: Unknown"

9 Answers9

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