in maven-wrapper-plugin/src/main/java/org/apache/maven/plugins/wrapper/WrapperMojo.java [188:210]
public void execute() throws MojoExecutionException {
final Path baseDir = Paths.get(session.getRequest().getBaseDirectory());
final Path wrapperDir = baseDir.resolve(WRAPPER_DIR);
if (distributionType == null) {
distributionType = determineDistributionType(wrapperDir);
}
if (mvndVersion != null && mvndVersion.length() > 0 && !TYPE_ONLY_SCRIPT.equals(distributionType)) {
throw new MojoExecutionException("maven-wrapper with type=" + distributionType
+ " cannot work with mvnd, please set type to '" + TYPE_ONLY_SCRIPT + "'.");
}
mavenVersion = getVersion(mavenVersion, Maven.class, "org.apache.maven/maven-core");
String wrapperVersion = getVersion(null, this.getClass(), "org.apache.maven.plugins/maven-wrapper-plugin");
final Artifact artifact = downloadWrapperDistribution(wrapperVersion);
createDirectories(wrapperDir);
cleanup(wrapperDir);
unpack(artifact, baseDir);
replaceProperties(wrapperVersion, wrapperDir);
}