org.apache.maven.plugins.enforcer.RequireUpperBoundDeps 失败并显示以下消息：

Question

When I run "mvn clean install " I got those errors, what's the correct way to fix this issue? i tried to change the version of junit-jupiter to 5.7.0 but it cause more errors, can anyone help me with that?

[WARNING] Rule 1: org.apache.maven.plugins.enforcer.RequireUpperBoundDeps failed with message:
Failed while enforcing RequireUpperBoundDeps. The error(s) are [
Require upper bound dependencies error for org.junit.jupiter:junit-jupiter-api:5.5.2 paths to dependency are:
+-my-service:1.0.0-SNAPSHOT
  +-org.junit.jupiter:junit-jupiter-api:5.5.2
and
+-my-service:1.0.0-SNAPSHOT
  +-org.junit.jupiter:junit-jupiter-engine:5.5.2
    +-org.junit.jupiter:junit-jupiter-api:5.5.2
and
+-my-service:1.0.0-SNAPSHOT
  +-org.springframework.boot:spring-boot-starter-test:2.4.1
    +-org.junit.jupiter:junit-jupiter:5.7.0
      +-org.junit.jupiter:junit-jupiter-api:5.5.2 (managed) <-- org.junit.jupiter:junit-jupiter-api:5.7.0
and
+-my-service:1.0.0-SNAPSHOT
  +-org.springframework.boot:spring-boot-starter-test:2.4.1
    +-org.mockito:mockito-junit-jupiter:3.6.28
      +-org.junit.jupiter:junit-jupiter-api:5.5.2 (managed) <-- org.junit.jupiter:junit-jupiter-api:5.4.2
and
+-my-service:1.0.0-SNAPSHOT
  +-org.springframework.boot:spring-boot-starter-test:2.4.1
    +-org.junit.jupiter:junit-jupiter:5.7.0
      +-org.junit.jupiter:junit-jupiter-params:5.7.0
        +-org.junit.jupiter:junit-jupiter-api:5.5.2 (managed) <-- org.junit.jupiter:junit-jupiter-api:5.7.0
, 

Answer 1

Maven determines the artifact versions with nearest definition rule. That is, it uses the version of the closest dependency to your project in the tree of dependencies. You can always guarantee a version by declaring it explicitly in your project's POM. Note that if two dependency versions are at the same depth in the dependency tree, the first declaration wins.

Example: Shallowest one wins.

Your project dependencies
 ​+-A
   ​+-B
     ​+-C
       ​+-D-2.0
 ​+-E
   ​+-D-1.0    <- This version is used for artifact D as this is "nearest".

Solution : update the version in the pom.xml to the newest version listed in the output ie 5.7.0 in your case.

You can print the dependency tree mvn dependency:tree and see where you are getting the conflicts in actual.

Answer 2

The rule seems to enforce a common upper bounds for a set of dependencies : this may be used to achieve binary compatibility (eg: to ensure that you don't use a lower version that would be incompatible with a transitive dependency you use because its version would be greater).

[WARNING] Rule 1: org.apache.maven.plugins.enforcer.RequireUpperBoundDeps failed with message:
Failed while enforcing RequireUpperBoundDeps. The error(s) are [
Require upper bound dependencies error for org.junit.jupiter:junit-jupiter-api:5.5.2 paths to dependency are:
+-my-service:1.0.0-SNAPSHOT
  +-org.junit.jupiter:junit-jupiter-api:5.5.2
and
+-my-service:1.0.0-SNAPSHOT
  +-org.junit.jupiter:junit-jupiter-engine:5.5.2
    +-org.junit.jupiter:junit-jupiter-api:5.5.2
and
+-my-service:1.0.0-SNAPSHOT
  +-org.springframework.boot:spring-boot-starter-test:2.4.1
    +-org.junit.jupiter:junit-jupiter:5.7.0
      +-org.junit.jupiter:junit-jupiter-api:5.5.2 (managed) <-- org.junit.jupiter:junit-jupiter-api:5.7.0

spring boot is importing junit at version 5.7.0, but you have specified junit 5.5.2.

Try to use the highest version (eg: 5.7.0).