| # Usage |
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| |
| Wrapper scripts are a set of files that can be added to your Maven project. |
| If people want to build this project, they don't need to install Maven first. |
| Instead they can call the Maven wrapper script (like `mvnw`/`mvnw.cmd`), which will download and unpack Maven into their `${user.home}/.m2/wrapper/dists` folder. |
| It is also an easy way to let everyone build the project with the same Maven version. |
| |
| The Apache Maven Wrapper Plugin makes it easier to add these wrapper scripts to your project. |
| |
| The scripts work like this: |
| - download the maven-wrapper jar, if it is not available yet, |
| - the wrapper-jar contains the code to download and run Apache Maven |
| |
| Apache Maven Wrapper Distribution Types |
| ----- |
| |
| Wrapper scripts are provided by Maven 4 releases as ["Apache Maven Wrapper Distribution"](/ref/4-LATEST/apache-maven-wrapper/). |
| |
| There are 3 types available: |
| |
| - **script** _(default)_: With this type the scripts will try to download the scripts via wget or curl in case of Unix based system, or use Powershell in case of Windows |
| |
| |
| - **bin**: With this type the maven-wrapper jar is already available in the `.mvn/wrapper` folder, so you don't have to rely on wget/curl or Powershell |
| The downside is that the project will contain a binary file in the source control management system. |
| |
| - **source**: Since Maven already requires Java to run, why not compile and run a classfile to download the maven-wrapper jar? |
| This type comes with a `.mvn/wrapper/MavenWrapperDownloader.java` which will be compiled and executed on the fly. |
| |
| Maven Version |
| ------------- |
| By default the plugin will assume the same version as the Maven runtime (calling `mvn -v`). But you can pick a different version. |
| Either call `mvn wrapper -DmavenVersion=x`, where x is any valid Apache Maven Release, see https://search.maven.org/artifact/org.apache.maven/apache-maven |
| Another option is adjust the `distributionUrl` in `.mvn/wrapper/maven-wrapper.properties` |
| |
| Debugging |
| --------- |
| |
| The apache-maven-wrapper distributions all contains the `mvnwDebug`-script for both Windows and Unix based operating systems. |
| This makes it possible to debug through Apache Maven, Maven Plugin or Maven Extension. |
| You can exclude these scripts by calling `mvn wrapper -DincludeDebug=false` |
