package org.apache.maven.wrapper;
   
   /*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you under the Apache License, Version 2.0 (the
    * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   *
   *  http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   * KIND, either express or implied.  See the License for the
   * specific language governing permissions and limitations
   * under the License.
   */
  
  import java.io.FileNotFoundException;
  import java.io.IOException;
  import java.lang.reflect.Method;
  import java.net.URL;
  import java.net.URLClassLoader;
  import java.nio.file.DirectoryStream;
  import java.nio.file.Files;
  import java.nio.file.Path;
  import java.util.Iterator;
  import java.util.Locale;
  
  /**
   * Maven starter, from a provided Maven home directory.
   *
   * @author Hans Dockter
   */
  public class BootstrapMainStarter
  {
      public void start( String[] args, Path mavenHome )
          throws Exception
      {
          final Path mavenJar = findLauncherJar( mavenHome );
          URLClassLoader contextClassLoader = new URLClassLoader( new URL[] { mavenJar.toUri().toURL() },
                                                                  ClassLoader.getSystemClassLoader().getParent() );
          Thread.currentThread().setContextClassLoader( contextClassLoader );
          Class<?> mainClass = contextClassLoader.loadClass( "org.codehaus.plexus.classworlds.launcher.Launcher" );
  
          System.setProperty( "maven.home", mavenHome.toAbsolutePath().toString() );
          System.setProperty( "classworlds.conf", mavenHome.resolve( "bin/m2.conf" ).toAbsolutePath().toString() );
  
          Method mainMethod = mainClass.getMethod( "main", String[].class );
          mainMethod.invoke( null, new Object[] { args } );
      }
  
      private Path findLauncherJar( Path mavenHome )
          throws IOException
      {
          final Path mavenBoot = mavenHome.resolve( "boot" );
          if ( Files.isDirectory( mavenBoot ) )
          {
              try ( DirectoryStream<Path> ds = Files.newDirectoryStream( mavenBoot, "plexus-classworlds-*.jar" ) )
              {
                  Iterator<Path> iterator = ds.iterator();
                  if ( iterator.hasNext() )
                  {
                      return iterator.next();
                  }
              }
          }
          throw new FileNotFoundException( String.format( Locale.ROOT, "Could not locate the Maven launcher JAR"
              + " in Maven distribution '%s'.", mavenHome ) );
      }
  }