Increment version and update pom.xml <version> in Azure DevOps pipeline - maven

Question

I am trying to increment the version number for my builds and then update the pom.xml file with the new version. My Powershell to edit and save the pom.xml does not seem to work, I don't get it to reach the xml.project.version i.e. < version > tag and make changes to it.
Do you have any suggestion how to get it to find the < version > tag and save the updated document?
For additional info, the DevOps pipeline runs in windows-latest at the moment.
trigger:
branches:
include:
- localdev
variables:
- name: azureSubscription
value: 'xxxx'
- name: webAppName
value: 'xxx'
- name: environmentName
value: 'xxx'
- name: vmImageName
value: 'ubuntu-latest'
- name: version.MajorMinor
value: '1.0'
- name: version.Patch
value: $[counter(variables['version.MajorMinor'], 0)]
- name: stableVersionNumber
value: '$(version.MajorMinor).$(version.Patch)'
- name: prereleaseVersionNumber
value: 'Set dynamically below in a task'
- name: versionNumber
value: 'Set dynamically below in a task'
- name: isMainBranch
value: $[eq(variables['Build.SourceBranch'], 'refs/heads/main')]
stages:
- stage: Build
displayName: Build stage
jobs:
- job: Fixversionnumber
displayName: Fix Version number
pool:
vmImage: $(vmImageName)
steps:
- task: PowerShell#2
displayName: Set the prereleaseVersionNumber variable value
inputs:
targetType: 'inline'
script: |
[string] $prereleaseVersionNumber = "$(stableVersionNumber)"
Write-Host "Setting the prerelease version number variable to '$prereleaseVersionNumber'."
Write-Host "##vso[task.setvariable variable=prereleaseVersionNumber]$prereleaseVersionNumber"
- task: PowerShell#2
displayName: Set the versionNumber to the stable or prerelease version number based on if the 'main' branch is being built or not
inputs:
targetType: 'inline'
script: |
[bool] $isMainBranch = $$(isMainBranch)
[string] $versionNumber = "$(prereleaseVersionNumber)"
if ($isMainBranch)
{
$versionNumber = "$(stableVersionNumber)"
}
Write-Host "Setting the version number to use to '$versionNumber'."
Write-Host "##vso[task.setvariable variable=versionNumber]$versionNumber"
- task: PowerShell#2
displayName: Set the name of the build (i.e. the Build.BuildNumber)
inputs:
targetType: 'inline'
script: |
[string] $buildName = "$(versionNumber)_$(Build.SourceBranchName)"
Write-Host "Setting the name of the build to '$buildName'."
Write-Host "##vso[build.updatebuildnumber]$buildName"
- task: PowerShell#2
displayName: Set the name of the build (i.e. the Build.BuildNumber)
inputs:
targetType: 'inline'
script: |
#Get version
$versionNum = "$(versionNumber)"
# Specify the file path
#$xmlFileName= "pom.xml"
# Read the existing file
[xml]$xml = Get-Content "pom.xml"
#[xml]$xmlDoc = Get-Content pom.xml
# If it was one specific element you can just do like so:
$xml.project.version = "$versionNum"
#Remove the old pom.xml
#Remove-Item $xmlFileName
# Then you can save that back to the xml file
$xml.Save("$(System.DefaultWorkingDirectory)\pom.xml")
# Print new file content
Write-Host "#########################################'$versionNum'.#########################################"
Write-Host "Setting the version number to use to '$versionNum'."
Write-Host "######################################### '$versionNum'.#########################################"
gc $(System.DefaultWorkingDirectory)\pom.xml
- task: Maven#3
displayName: 'Maven Package'
inputs:
mavenPomFile: 'pom.xml'
- task: CopyFiles#2
displayName: 'Copy Files to artifact staging directory'
inputs:
SourceFolder: '$(System.DefaultWorkingDirectory)'
Contents: '**/target/*.?(war|jar)'
TargetFolder: $(Build.ArtifactStagingDirectory)
- task: buildDropFile
inputs:
targetPath: $(Build.ArtifactStagingDirectory)
artifactName: drop

Answer 1

You can use a third party extension Replace Tokens. It can search files to find what to replace by a parameter tokenPattern and replaces values with variables in the pipeline. Click "Git if free" and download it to your organization.
In your pom.xml file, please replace your version number to a unique value, like #{version}#.
<version>#{versionNumber}#</version>
Please notice the #{...}#, this will help task to find which content to replace. The versionNumber should be the variable that you want to replace.
Then, in your pipeline, search and add a replace tokens task. Here is an example:
steps:
- task: replacetokens#5
inputs:
targetFiles: '**/pom.xml'
encoding: 'auto'
tokenPattern: 'default' # The defult token pattern is #{...}#
writeBOM: true
actionOnMissing: 'continue'
keepToken: false
actionOnNoFiles: 'continue'
enableTransforms: false
enableRecursion: false
useLegacyPattern: false
enableTelemetry: true