package org.apache.maven.plugins.enforcer;
   
   /*
    * 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.util.Arrays;
  import java.util.Iterator;
  import java.util.List;
  
  import org.apache.commons.lang3.SystemUtils;
  import org.apache.maven.artifact.versioning.ArtifactVersion;
  import org.apache.maven.artifact.versioning.DefaultArtifactVersion;
  import org.apache.maven.enforcer.rule.api.EnforcerRuleException;
  import org.apache.maven.enforcer.rule.api.EnforcerRuleHelper;
  import org.apache.maven.plugin.logging.Log;
  import org.codehaus.plexus.util.StringUtils;
  
  /**
   * This rule checks that the Java version is allowed.
   *
   * @author <a href="mailto:brianf@apache.org">Brian Fox</a>
   * @version $Id$
   */
  public class RequireJavaVersion
      extends AbstractVersionEnforcer
  {
      @Override
      public void execute( EnforcerRuleHelper helper )
          throws EnforcerRuleException
      {
          String javaVersion = SystemUtils.JAVA_VERSION;
          Log log = helper.getLog();
  
          log.debug( "Detected Java String: '" + javaVersion + "'" );
          javaVersion = normalizeJDKVersion( javaVersion );
          log.debug( "Normalized Java String: '" + javaVersion + "'" );
  
          ArtifactVersion detectedJdkVersion = new DefaultArtifactVersion( javaVersion );
  
          log.debug( "Parsed Version: Major: " + detectedJdkVersion.getMajorVersion() + " Minor: "
              + detectedJdkVersion.getMinorVersion() + " Incremental: " + detectedJdkVersion.getIncrementalVersion()
              + " Build: " + detectedJdkVersion.getBuildNumber() + " Qualifier: " + detectedJdkVersion.getQualifier() );
  
          enforceVersion( helper.getLog(), "JDK", getVersion(), detectedJdkVersion );
      }
  
      /**
       * Converts a jdk string from 1.5.0-11b12 to a single 3 digit version like 1.5.0-11
       *
       * @param theJdkVersion to be converted.
       * @return the converted string.
       */
      public static String normalizeJDKVersion( String theJdkVersion )
      {
  
          theJdkVersion = theJdkVersion.replaceAll( "_|-", "." );
          String tokenArray[] = StringUtils.split( theJdkVersion, "." );
          List<String> tokens = Arrays.asList( tokenArray );
          StringBuffer buffer = new StringBuffer( theJdkVersion.length() );
  
          Iterator<String> iter = tokens.iterator();
          for ( int i = 0; i < tokens.size() && i < 4; i++ )
          {
              String section = (String) iter.next();
              section = section.replaceAll( "[^0-9]", "" );
  
              if ( StringUtils.isNotEmpty( section ) )
              {
                  buffer.append( Integer.parseInt( section ) );
  
                  if ( i != 2 )
                  {
                      buffer.append( '.' );
                  }
                  else
                  {
                      buffer.append( '-' );
                  }
              }
          }
  
          String version = buffer.toString();
          version = StringUtils.stripEnd( version, "-" );
         return StringUtils.stripEnd( version, "." );
     }
 }