core-it-support/core-it-plugins/maven-it-plugin-site/src/main/java/org/apache/maven/plugin/coreit/ListMojo.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.AbstractMojo;
import org.apache.maven.plugin.MojoExecutionException;
import org.apache.maven.plugin.MojoFailureException;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.List;
import java.util.Properties;

/**
 * Lists the available/configured reports in a properties file.
 * 
 * @goal list
 * @phase initialize
 * @requiresReports true
 * 
 * @author Benjamin Bentmann
 *
 */
public class ListMojo
    extends AbstractMojo
{

    /**
     * The path to the properties file used to list the available reports. The properties file will have a key named
     * <code>reports</code> that gives the total count of reports. The keys <code>reports.0</code>,
     * <code>reports.1</code> etc. will be used to denote the qualified class names of the reports.
     * 
     * @parameter property="site.properties" default-value="target/reports.properties"
     */
    private File reportsFile;

    /**
     * The reports configured for the current build.
     * 
     * @parameter default-value="${reports}"
     * @required
     * @readonly
     */
    private List reports;

    /**
     * Runs this mojo.
     * 
     * @throws MojoExecutionException If the output file could not be created.
     */
    public void execute()
        throws MojoExecutionException, MojoFailureException
    {
        Properties reportProperties = new Properties();

        reportProperties.setProperty( "reports", "" + reports.size() );

        for ( int i = 0; i < reports.size(); i++ )
        {
            Object report = reports.get( i );
            getLog().info( "[MAVEN-CORE-IT-LOG] Listing report " + report );
            reportProperties.setProperty( "reports." + i, report.getClass().getName() );
        }

        getLog().info( "[MAVEN-CORE-IT-LOG] Creating output file " + reportsFile );

        reportsFile.getParentFile().mkdirs();
        try ( OutputStream out = new FileOutputStream( reportsFile ) )
        {
            reportProperties.store( out, "MAVEN-CORE-IT-LOG" );
        }
        catch ( IOException e )
        {
            throw new MojoExecutionException( "Output file could not be created: " + reportsFile, e );
        }

        getLog().info( "[MAVEN-CORE-IT-LOG] Created output file " + reportsFile );
    }

}