core-it-support/core-it-plugins/maven-it-plugin-configuration/src/main/java/org/apache/maven/plugin/coreit/PropertiesUtil.java

package org.apache.maven.plugin.coreit;

/*
 * 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.codehaus.plexus.configuration.PlexusConfiguration;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.reflect.Array;
import java.text.SimpleDateFormat;
import java.util.Collection;
import java.util.Date;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Properties;

/**
 * Assists in handling properties.
 *
 * @author Benjamin Bentmann
 */
class PropertiesUtil
{

    public static Properties read( File inputFile )
        throws MojoExecutionException
    {
        Properties props = new Properties();

        if ( inputFile.exists() )
        {
            InputStream is = null;
            try
            {
                is = new FileInputStream( inputFile );
                props.load( is );
            }
            catch ( IOException e )
            {
                throw new MojoExecutionException( "Input file " + inputFile + " could not be read: " + e.getMessage(),
                                                  e );
            }
            finally
            {
                if ( is != null )
                {
                    try
                    {
                        is.close();
                    }
                    catch ( IOException e )
                    {
                        // just ignore
                    }
                }
            }
        }

        return props;
    }

    public static void write( File outputFile, Properties props )
        throws MojoExecutionException
    {
        OutputStream os = null;
        try
        {
            outputFile.getParentFile().mkdirs();
            os = new FileOutputStream( outputFile );
            props.store( os, "MAVEN-CORE-IT-LOG" );
        }
        catch ( IOException e )
        {
            throw new MojoExecutionException( "Output file " + outputFile + " could not be created: " + e.getMessage(),
                                              e );
        }
        finally
        {
            if ( os != null )
            {
                try
                {
                    os.close();
                }
                catch ( IOException e )
                {
                    // just ignore
                }
            }
        }
    }

    public static void serialize( Properties props, String key, Object value )
    {
        if ( value != null && value.getClass().isArray() )
        {
            props.setProperty( key, Integer.toString( Array.getLength( value ) ) );
            for ( int i = Array.getLength( value ) - 1; i >= 0; i-- )
            {
                serialize( props, key + "." + i, Array.get( value, i ) );
            }
        }
        else if ( value instanceof Collection )
        {
            Collection collection = (Collection) value;
            props.setProperty( key, Integer.toString( collection.size() ) );
            int i = 0;
            for ( Iterator it = collection.iterator(); it.hasNext(); i++ )
            {
                serialize( props, key + "." + i, it.next() );
            }
        }
        else if ( value instanceof Map )
        {
            Map map = (Map) value;
            props.setProperty( key, Integer.toString( map.size() ) );
            int i = 0;
            for ( Iterator it = map.keySet().iterator(); it.hasNext(); i++ )
            {
                Object k = it.next();
                Object v = map.get( k );
                serialize( props, key + "." + k, v );
            }
        }
        else if ( value instanceof PlexusConfiguration )
        {
            PlexusConfiguration config = (PlexusConfiguration) value;

            String val = config.getValue( null );
            if ( val != null )
            {
                props.setProperty( key + ".value", val );
            }

            String[] attributes = config.getAttributeNames();
            props.setProperty( key + ".attributes", Integer.toString( attributes.length ) );
            for ( int i = attributes.length - 1; i >= 0; i-- )
            {
                props.setProperty( key + ".attributes." + attributes[i], config.getAttribute( attributes[i], "" ) );
            }

            PlexusConfiguration children[] = config.getChildren();
            props.setProperty( key + ".children", Integer.toString( children.length ) );
            Map<String, Integer> indices = new HashMap<>();
            for ( PlexusConfiguration child : children )
            {
                String name = child.getName();
                Integer index = indices.get( name );
                if ( index == null )
                {
                    index = 0;
                }
                serialize( props, key + ".children." + name + "." + index, child );
                indices.put( name, index + 1 );
            }
        }
        else if ( value instanceof Date )
        {
            props.setProperty( key, new SimpleDateFormat( "yyyy-MM-dd HH:mm:ss" ).format( (Date) value ) );
        }
        else if ( value != null )
        {
            props.setProperty( key, value.toString() );
        }
    }

}