src/main/java/org/apache/maven/plugins/jlink/AbstractJLinkToolchainExecutor.java

package org.apache.maven.plugins.jlink;

/*
 * 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 org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.SystemUtils;
import org.apache.maven.plugin.MojoExecutionException;
import org.apache.maven.plugin.logging.Log;
import org.apache.maven.shared.utils.cli.CommandLineException;
import org.apache.maven.shared.utils.cli.CommandLineUtils;
import org.apache.maven.shared.utils.cli.Commandline;
import org.apache.maven.toolchain.Toolchain;

import java.io.File;
import java.util.List;
import java.util.NoSuchElementException;
import java.util.Optional;

abstract class AbstractJLinkToolchainExecutor extends AbstractJLinkExecutor
{
    private final Toolchain toolchain;

    AbstractJLinkToolchainExecutor( Toolchain toolchain, Log log )
    {
        super( log );
        this.toolchain = toolchain;
    }

    protected Optional<Toolchain> getToolchain()
    {
        return Optional.ofNullable( this.toolchain );
    }

    /**
     * Execute JLink via toolchain.
     *
     * @return the exit code ({@code 0} on success).
     */
    @Override
    public int executeJlink( List<String> jlinkArgs ) throws MojoExecutionException
    {
        File jlinkExecutable = getJlinkExecutable();
        getLog().info( "Toolchain in maven-jlink-plugin: jlink [ " + jlinkExecutable + " ]" );

        Commandline cmd = createJLinkCommandLine( jlinkArgs );
        cmd.setExecutable( jlinkExecutable.getAbsolutePath() );

        return executeCommand( cmd );
    }

    private File getJlinkExecutable()
    {
        return new File( getJLinkExecutable() );
    }

    @Override
    public Optional<File> getJmodsFolder( /* nullable */ File sourceJdkModules )
    {
        // Really Hacky...do we have a better solution to find the jmods directory of the JDK?
        File jLinkParent = getJlinkExecutable().getParentFile().getParentFile();
        File jmodsFolder;
        if ( sourceJdkModules != null && sourceJdkModules.isDirectory() )
        {
            jmodsFolder = new File( sourceJdkModules, JMODS );
        }
        else
        {
            jmodsFolder = new File( jLinkParent, JMODS );
        }

        getLog().debug( " Parent: " + jLinkParent.getAbsolutePath() );
        getLog().debug( " jmodsFolder: " + jmodsFolder.getAbsolutePath() );

        return Optional.of( jmodsFolder );
    }

    private Commandline createJLinkCommandLine( List<String> jlinkArgs )
    {
        Commandline cmd = new Commandline();
        jlinkArgs.forEach( arg -> cmd.createArg().setValue( arg ) );

        return cmd;
    }

    private String getJLinkExecutable()
    {
        Optional<Toolchain> toolchain = getToolchain();

        if ( !toolchain.isPresent() )
        {
            getLog().error( "Either JDK9+ or a toolchain "
                    + "pointing to a JDK9+ containing a jlink binary is required." );
            getLog().info( "See https://maven.apache.org/guides/mini/guide-using-toolchains.html "
                    + "for mor information." );
            throw new IllegalStateException( "Running on JDK8 and no toolchain found." );
        }

        String jLinkExecutable = toolchain.orElseThrow( NoSuchElementException::new ).findTool( "jlink" );

        if ( jLinkExecutable.isEmpty() )
        {
            throw new IllegalStateException( "The jlink executable '"
                    + jLinkExecutable + "' doesn't exist or is not a file." );
        }

        // TODO: Check if there exist a more elegant way?
        String jLinkCommand = "jlink" + ( SystemUtils.IS_OS_WINDOWS ? ".exe" : "" );

        File jLinkExe = new File( jLinkExecutable );

        if ( jLinkExe.isDirectory() )
        {
            jLinkExe = new File( jLinkExe, jLinkCommand );
        }

        if ( SystemUtils.IS_OS_WINDOWS && jLinkExe.getName().indexOf( '.' ) < 0 )
        {
            jLinkExe = new File( jLinkExe.getPath() + ".exe" );
        }

        if ( !jLinkExe.isFile() )
        {
            throw new IllegalStateException( "The jlink executable '"
                    + jLinkExe + "' doesn't exist or is not a file." );
        }
        return jLinkExe.getAbsolutePath();
    }

    private int executeCommand( Commandline cmd )
            throws MojoExecutionException
    {
        if ( getLog().isDebugEnabled() )
        {
            // no quoted arguments ???
            getLog().debug( CommandLineUtils.toString( cmd.getCommandline() ).replaceAll( "'", "" ) );
        }

        CommandLineUtils.StringStreamConsumer err = new CommandLineUtils.StringStreamConsumer();
        CommandLineUtils.StringStreamConsumer out = new CommandLineUtils.StringStreamConsumer();
        try
        {
            int exitCode = CommandLineUtils.executeCommandLine( cmd, out, err );

            String output = ( StringUtils.isEmpty( out.getOutput() ) ? null : '\n' + out.getOutput().trim() );

            if ( exitCode != 0 )
            {

                if ( StringUtils.isNotEmpty( output ) )
                {
                    // Reconsider to use WARN / ERROR ?
                    //  getLog().error( output );
                    for ( String outputLine : output.split( "\n" ) )
                    {
                        getLog().error( outputLine );
                    }
                }

                StringBuilder msg = new StringBuilder( "\nExit code: " );
                msg.append( exitCode );
                if ( StringUtils.isNotEmpty( err.getOutput() ) )
                {
                    msg.append( " - " ).append( err.getOutput() );
                }
                msg.append( '\n' );
                msg.append( "Command line was: " ).append( cmd ).append( '\n' ).append( '\n' );

                throw new MojoExecutionException( msg.toString() );
            }

            if ( StringUtils.isNotEmpty( output ) )
            {
                //getLog().info( output );
                for ( String outputLine : output.split( "\n" ) )
                {
                    getLog().info( outputLine );
                }
            }

            return exitCode;
        }
        catch ( CommandLineException e )
        {
            throw new MojoExecutionException( "Unable to execute jlink command: " + e.getMessage(), e );
        }
    }
}