maven-core/src/main/java/org/apache/maven/rtinfo/internal/DefaultRuntimeInformation.java

package org.apache.maven.rtinfo.internal;

/*
 * 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.Validate;
import org.apache.maven.rtinfo.RuntimeInformation;
import org.eclipse.aether.version.InvalidVersionSpecificationException;
import org.eclipse.aether.version.Version;
import org.eclipse.aether.version.VersionConstraint;
import org.eclipse.aether.version.VersionScheme;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

import javax.inject.Inject;
import javax.inject.Named;
import javax.inject.Singleton;

/**
 * Provides information about the current Maven runtime.
 */
@Named
@Singleton
public class DefaultRuntimeInformation
    implements RuntimeInformation
{
    private final Logger logger = LoggerFactory.getLogger( getClass() );

    private final VersionScheme versionScheme;

    private final String mavenVersion;

    @Inject
    public DefaultRuntimeInformation( final VersionScheme versionScheme )
    {
        this.versionScheme = versionScheme;
        this.mavenVersion = loadMavenVersion();
    }

    @Override
    public String getMavenVersion()
    {
        return mavenVersion;
    }

    private String loadMavenVersion()
    {
        Properties props = new Properties();

        String resource = "META-INF/maven/org.apache.maven/maven-core/pom.properties";

        try ( InputStream is = DefaultRuntimeInformation.class.getResourceAsStream( "/" + resource ) )
        {
            if ( is != null )
            {
                props.load( is );
            }
            else
            {
                logger.warn(
                    "Could not locate " + resource + " on classpath, Maven runtime information not available" );
            }
        }
        catch ( IOException e )
        {
            String msg = "Could not parse " + resource + ", Maven runtime information not available";
            if ( logger.isDebugEnabled() )
            {
                logger.warn( msg, e );
            }
            else
            {
                logger.warn( msg );
            }
        }

        String version = props.getProperty( "version", "" ).trim();

        if ( !version.startsWith( "${" ) )
        {
            return version;
        }
        else
        {
            return "";
        }
    }

    @Override
    public boolean isMavenVersion( String versionRange )
    {
        Validate.notBlank( versionRange, "versionRange can neither be null, empty nor blank" );

        VersionConstraint constraint;
        try
        {
            constraint = versionScheme.parseVersionConstraint( versionRange );
        }
        catch ( InvalidVersionSpecificationException e )
        {
            throw new IllegalArgumentException( e.getMessage(), e );
        }

        Version current;
        try
        {
            String mavenVersion = getMavenVersion();
            Validate.validState( StringUtils.isNotEmpty( mavenVersion ), "Could not determine current Maven version" );

            current = versionScheme.parseVersion( mavenVersion );
        }
        catch ( InvalidVersionSpecificationException e )
        {
            throw new IllegalStateException( "Could not parse current Maven version: " + e.getMessage(), e );
        }

        if ( constraint.getRange() == null )
        {
            return constraint.getVersion().compareTo( current ) <= 0;
        }
        return constraint.containsVersion( current );
    }

}