src/test/java/org/apache/commons/configuration2/TestSystemConfiguration.java

/*
 * 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.
 */

package org.apache.commons.configuration2;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;

import java.io.File;
import java.io.IOException;
import java.util.Iterator;
import java.util.Properties;
import java.util.concurrent.atomic.AtomicBoolean;

import org.apache.commons.configuration2.ex.ConfigurationException;
import org.apache.commons.configuration2.io.FileHandler;
import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.TemporaryFolder;

/**
 * Tests for {@code SystemConfiguration}.
 *
 */
public class TestSystemConfiguration
{
    /** An object for creating temporary files. */
    @Rule
    public TemporaryFolder folder = new TemporaryFolder();

    @Test
    public void testSystemConfiguration()
    {
        final Properties props = System.getProperties();
        props.put("test.number", "123");

        final Configuration conf = new SystemConfiguration();
        assertEquals("number", 123, conf.getInt("test.number"));
    }

    @Test
    public void testSetSystemProperties()
    {
        final PropertiesConfiguration props = new PropertiesConfiguration();
        props.addProperty("test.name", "Apache");
        SystemConfiguration.setSystemProperties(props);
        assertEquals("System Properties", "Apache", System.getProperty("test.name"));
    }

    /**
     * Tests whether system properties can be set from a configuration file.
     */
    @Test
    public void testSetSystemPropertiesFromPropertiesFile()
            throws ConfigurationException, IOException
    {
        final File file = folder.newFile("sys.properties");
        final PropertiesConfiguration pconfig = new PropertiesConfiguration();
        final FileHandler handler = new FileHandler(pconfig);
        pconfig.addProperty("fromFile", Boolean.TRUE);
        handler.setFile(file);
        handler.save();
        SystemConfiguration.setSystemProperties(handler.getBasePath(),
                handler.getFileName());
        final SystemConfiguration sconf = new SystemConfiguration();
        assertTrue("Property from file not found", sconf.getBoolean("fromFile"));
    }

    /**
     * Tests whether the configuration can be used to change system properties.
     */
    @Test
    public void testChangeSystemProperties()
    {
        final String testProperty = "someTest";
        final SystemConfiguration config = new SystemConfiguration();
        config.setProperty(testProperty, "true");
        assertEquals("System property not changed", "true",
                System.getProperty(testProperty));
    }

    /**
     * Tests an append operation with a system configuration while system
     * properties are modified from another thread. This is related to
     * CONFIGURATION-570.
     */
    @Test
    public void testAppendWhileConcurrentAccess() throws InterruptedException
    {
        final AtomicBoolean stop = new AtomicBoolean();
        final String property =
                SystemConfiguration.class.getName() + ".testProperty";
        final Thread t = new Thread()
        {
            @Override
            public void run()
            {
                boolean setValue = true;
                while (!stop.get())
                {
                    if (setValue)
                    {
                        System.setProperty(property, "true");
                    }
                    else
                    {
                        System.clearProperty(property);
                    }
                    setValue = !setValue;
                }
            }
        };
        try
        {
            t.start();

            final SystemConfiguration config = new SystemConfiguration();
            final PropertiesConfiguration props = new PropertiesConfiguration();
            props.append(config);

            stop.set(true);
            t.join();
            for (final Iterator<String> keys = config.getKeys(); keys.hasNext();)
            {
                final String key = keys.next();
                if (!property.equals(key))
                {
                    assertEquals("Wrong value for " + key,
                            config.getString(key), props.getString(key));
                }
            }
        }
        finally
        {
            System.clearProperty(property);
        }
    }
}