[MWRAPPER-91] Concurrent execution of mvnw to download wrapper fails

**[Alexander Schwartz](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=ahus1)** opened **[MWRAPPER-91](https://issues.apache.org/jira/browse/MWRAPPER-91?redirect=false)** and commented

The script will download the executable maven wrapper JAR file directly to the final file name.
When multiple calls do this concurrently, it happens that the first call executes the JAR file that is currently overwritten by the second parallel call.

This leads to error like:
* `NoClassDefFoundError: org/codehaus/plexus/PlexusContainer`
* `ClassNotFoundException: org.apache.maven.wrapper.MavenWrapperMain`

A different solution might be to first download the JAR file to a temporary file, and then use an atomic file operator like a rename once the download is complete.

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**Affects:** 3.1.0

**Remote Links:**
- [GitHub Pull Request #137
](https://github.com/apache/maven-wrapper/pull/137)

1 votes, 5 watchers