PropUtils.java

/*-
 * Copyright © 2010 Diamond Light Source Ltd.
 *
 * This file is part of GDA.
 *
 * GDA is free software: you can redistribute it and/or modify it under the
 * terms of the GNU General Public License version 3 as published by the Free
 * Software Foundation.
 *
 * GDA is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License along
 * with GDA. If not, see <http://www.gnu.org/licenses/>.
 */

package uk.ac.gda.util.io;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.net.HttpURLConnection;
import java.util.Iterator;
import java.util.Properties;

public final class PropUtils {

	////////////////////////////////////////////////////////////////////////
	public final static Properties loadProperties(final String path) throws IOException {
		final File file                  = new File(path);
		return PropUtils.loadProperties(file);
	}
	////////////////////////////////////////////////////////////////////////
	public final static Properties loadProperties(final File file) throws IOException {
		final Properties fileProps       = new Properties();
		if (!file.exists()) return fileProps;
		InputStream stream = null;
		try {
			stream = new FileInputStream(file);
			final BufferedInputStream in     = new BufferedInputStream(stream);
			fileProps.load(in);
		}
		finally {
			IOUtils.close(stream,"Loading properties for file "+IOUtils.fileInfo(file));
		}
		return fileProps;
	}

	////////////////////////////////////////////////////////////////////////
	public final static Properties storeProperties(final Properties props,
			final String path) throws IOException{
		final File file                  = new File(path);
		return PropUtils.storeProperties(props, file);
	}

	////////////////////////////////////////////////////////////////////////
	public final static Properties storeProperties(final Properties props,
			final File file) throws IOException {

		if (!file.getParentFile().exists()) file.getParentFile().mkdirs();
		if (!file.exists()) file.createNewFile();
		BufferedOutputStream out = null;
		try {
			final FileOutputStream os        = new FileOutputStream(file);
			out   = new BufferedOutputStream(os);
			props.store(out, "GDA/SDA Properties. Please do not edit this file.");
		}
		finally {
			IOUtils.close(out,"Storing properties for file "+IOUtils.fileInfo(file));
		}
		return props;
	}

	public final static Properties storeKeys(final Properties props,
			final File file) throws IOException{

		if (!file.getParentFile().exists()) file.getParentFile().mkdirs();
		if (!file.exists()) file.createNewFile();

		PrintWriter out = null;
		try {
			out   = new PrintWriter(new FileWriter(file));
			final Iterator<?> it = props.keySet().iterator();
			while(it.hasNext()) out.println((String)it.next());
		} finally {
			IOUtils.close(out,"Storing keys for file "+IOUtils.fileInfo(file));
		}
		return props;
	}

	public static final Properties loadProperties(final HttpURLConnection connection) throws IOException {
		BufferedInputStream in    = null;
		final Properties urlProps = new Properties();
		try {
			final InputStream stream = connection.getInputStream();
			in     = new BufferedInputStream(stream);
			urlProps.load(in);
		} finally {
			if (in!=null) {
				IOUtils.close(in,"Loading properties from URL");
				connection.disconnect();  // Must do for HTTP because servers have limited connections
			}
		}
		return urlProps;
	}
}