maven error summary

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1. After updating the maven project, it is found that the pom.xml file reports an error in the following dependencies: The
error message is: Missing artifact . .. ...
Go to the current user's .m2 directory to view, the jar file has been downloaded normally.

Solution:
1. Go to the corresponding directory of the .m2 that reported the error, and check whether there are files ending with the following in the directory:

-not-available
.lastUpdated Delete
these two files and rebuild them. If the problem is solved, it should be These two files have not been successfully downloaded before, which affects the normal update of maven.

2. If the above method is invalid, go to eclipse-help-install new software-available software sites and find the address where the m2eclipse plug-in was installed before, if it is http:/ /download.eclipse.org/technology/m2e/releases, uninstall it, and reinstall the m2eclipse plugin at the following address:

http://m2eclipse.sonatype.org/sites/m2e First, use Close Project to close the problem project, and then open the Open Project; or use Project-Clean to rebuild the project

4. Is there a matching pom file in the directory where the jar package is located?

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2. When updating maven, report "could not calculate build plan:..."
1. Reason: The corresponding maven plugin or package has an unsuccessfully downloaded file in the local maven repository: the ".lastUpdated" file, which prevents re-updating.
2. Solution: delete this file and update it again.
Batch deletion instructions:
cd to the maven local repository:
win execute: cd ./ for /r %i in (*.lastUpdated) do del %i
linux execute: find ./ -name "*.lastUpdated" -exec grep -q "Could not transfer" {} \; -print -exec rm {} \;