SessionIO.java

/*
 * Copyright (C) 2010 Brockmann Consult GmbH (info@brockmann-consult.de)
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 3 of the License, or (at your option)
 * any later version.
 * This program 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 this program; if not, see http://www.gnu.org/licenses/
 */

package org.esa.snap.rcp.session;

import com.bc.ceres.core.Assert;

import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.Reader;
import java.io.Writer;

/**
 * The Session I/O class is used to store and restore sessions.
 *
 * @author Norman Fomferra
 * @version $Revision$ $Date$
 * @since BEAM 4.6
 */
public abstract class SessionIO {
    static SessionIO instance = new XStreamSessionIO();

    public static SessionIO getInstance() {
        return instance;
    }

    public static void setInstance(SessionIO instance) {
        Assert.notNull(instance, "instance");
        SessionIO.instance = instance;
    }

    public Session readSession(File file)  throws Exception {
        Assert.notNull(file, "file");
        try (FileReader reader = new FileReader(file)) {
            return readSession(reader);
        }
    }

    public abstract Session readSession(Reader reader) throws Exception;

    public void writeSession(Session session, File file)  throws Exception {
        Assert.notNull(session, "session");
        Assert.notNull(file, "file");
        try (FileWriter writer = new FileWriter(file)) {
            writeSession(session, writer);
        }
    }

    public abstract void writeSession(Session session, Writer writer)  throws Exception;
}