org.apache.maven.plugins.artifact.buildinfo.JdkToolchainUtil Maven / Gradle / Ivy

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package org.apache.maven.plugins.artifact.buildinfo;

/*
 * 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.IOException;
import java.util.ArrayList;
import java.util.List;

import org.apache.maven.shared.utils.StringUtils;
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.shared.utils.cli.StreamConsumer;
import org.apache.maven.toolchain.Toolchain;

/**
 * A helper to get JDK version from a JDK toolchain.
 */
class JdkToolchainUtil
{
    static String getJavaVersion( Toolchain toolchain )
    {
        String version = "unknown";
        String java = toolchain.findTool( "java" );
        if ( java != null )
        {
            try
            {
                Commandline cl = new Commandline( java + " -version" );
                LineConsumer out = new LineConsumer(); 
                LineConsumer err = new LineConsumer(); 
                CommandLineUtils.executeCommandLine( cl, out, err );
                version = StringUtils.join( err.getLines().iterator(), ":" );
                if ( version == null )
                {
                    version = "unable to detect...";
                }
            }
            catch ( CommandLineException cle )
            {
                version = cle.toString();
            }
        }
        return version;
    }

    private static class LineConsumer implements StreamConsumer
    {
        private List lines = new ArrayList<>();

        @Override
        public void consumeLine( String line )
            throws IOException
        {
            lines.add( line );
        }

        List getLines()
        {
            return lines;
        }
    }
}