AbstractOpenJpaMappingToolMojo.java

package org.codehaus.mojo.openjpa;

/*
 * 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.maven.plugin.MojoExecutionException;
import org.apache.maven.plugin.MojoFailureException;
import org.codehaus.plexus.util.FileUtils;

import org.apache.openjpa.enhance.PersistenceCapable;
import org.apache.openjpa.jdbc.conf.JDBCConfiguration;
import org.apache.openjpa.jdbc.conf.JDBCConfigurationImpl;
import org.apache.openjpa.jdbc.meta.MappingTool;
import org.apache.openjpa.lib.conf.Configurations;
import org.apache.openjpa.lib.meta.ClassArgParser;
import org.apache.openjpa.lib.util.Options;
import org.apache.openjpa.meta.MetaDataRepository;

import java.io.File;
import java.io.IOException;
import java.sql.SQLException;
import java.util.Iterator;
import java.util.List;

import javax.persistence.Entity;

/**
 * Processes Application model classes and generate the DDL by running the 
 * OpenJPA MappingTool.
 * 
 * We have to split the generation of the SQL files and the mapping info
 * into 2 separate mojos, since the MappingTool struggles to generate both 
 * in one step.
 * 
 * @author <a href='mailto:struberg@yahoo.de'>Mark Struberg</a>
 * @version $Id$
 * @since 1.0
 */
public abstract class AbstractOpenJpaMappingToolMojo
    extends AbstractOpenJpaMojo
{
    /**
     * Argument to specify the action to take on each class. The available actions are:
     * buildSchema, validate
     * @parameter 
     */
    protected String action;
    /** used for passing the action parameter to the mapping tool */
    protected static final String OPTION_ACTION = "action";

    /**
     * {@inheritDoc}
     * 
     * @see org.apache.maven.plugin.Mojo#execute()
     */
    public void execute()
        throws MojoExecutionException, MojoFailureException
    {
        if ( skipMojo() )
        {
            return;
        }
        
        if ( !getEntityClasses().exists() )
        {
            FileUtils.mkdir( getEntityClasses().getAbsolutePath() );
        }
        
        List entities = findEntityClassFiles();

        mappingTool( entities );
    }

    /**
     * Processes a list of class file resources and perform the proper 
     * mapping action.
     * 
     * @param files class file resources to map.
     * @throws MojoExecutionException if the MappingTool detected an error
     */
    private void mappingTool( List files )
        throws MojoExecutionException
    {
        extendRealmClasspath();

        Options opts = getOptions();
        
        filterPersistenceCapable( files, opts );
        
        // list of input files
        final String[] args = getFilePaths( files );

        boolean ok = Configurations.runAgainstAllAnchors( opts,
            new Configurations.Runnable() {
              public boolean run( Options opts ) throws IOException, SQLException 
              {
                JDBCConfiguration conf = new JDBCConfigurationImpl();
                try 
                {
                    return MappingTool.run( conf, args, opts );
                } 
                finally 
                {
                    conf.close();
                }
              }
            } 
        );

        if ( !ok )
        {
            throw new MojoExecutionException( "The OpenJPA MappingTool detected an error!" );
        }
        
    }

    /**
     * Filter out all classes which are not PersistenceCapable.
     * This is needed since the MappingTool fails if it gets non-persistent capable classes.
     * @param files List with classPath Files; non persistence classes will be removed
     * @param opts filled configuration Options
     */
    private void filterPersistenceCapable( List files, Options opts )
    {
        JDBCConfiguration conf = new JDBCConfigurationImpl();
        Configurations.populateConfiguration( conf, opts );
        MetaDataRepository repo = conf.newMetaDataRepositoryInstance();
        ClassArgParser cap = repo.getMetaDataFactory().newClassArgParser();
        
        Iterator fileIt = files.iterator();
        while ( fileIt.hasNext() ) 
        {
            File classPath = (File) fileIt.next();

            Class[] classes = cap.parseTypes( classPath.getAbsolutePath() );

            if ( classes == null ) 
            {
                getLog().info( "Found no classes for " +  classPath.getAbsolutePath() );
            }
            else 
            {
                for ( int i = 0; i < classes.length; i++ ) 
                {
                    Class cls = classes[i];
                    
                    if ( cls.getAnnotation( Entity.class ) != null ) 
                    {
                        getLog().debug( "Found @Entity in class " + classPath );
                    }
                    else if ( implementsPersistenceCapable( cls ) ) 
                    {
                        getLog().debug( "Found class " + classPath + " that implements interface " 
                                        + PersistenceCapable.class.getName() );
                    }
                    else
                    {
                        getLog().debug( "Removing non-entity class " + classPath );
                        fileIt.remove();
                    }
                }
            }
        }
    }


    /**
     * @param cls the Class to check 
     * @return <code>true</code> if the given Class cls implements the interface {@link PersistenceCapable}
     */
    private boolean implementsPersistenceCapable( Class cls )
    {
        boolean isPersistenceCapable = false;
        Class[] interfaces  = cls.getInterfaces();
        for ( int i = 0; i < interfaces.length; i++ )
        {
            if ( interfaces[ i ].getName().equals( PersistenceCapable.class.getName() ) )
            {
                isPersistenceCapable = true;
                break;
            }
        }        
        
        return isPersistenceCapable;
    }

}