magarena/src/magic/model/MagicGameLog.java

package magic.model;

import magic.MagicMain;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.PrintWriter;
import java.text.SimpleDateFormat;
import java.util.Date;

public class MagicGameLog {

    private static final String gameLog = (System.getProperty("game.log") != null) ?
        System.getProperty("game.log") :       
        MagicMain.getLogsPath() + File.separator + "game.log";

    private static PrintWriter writer;

    private MagicGameLog() {}

    public static void initialize() {
        try {
            writer = new PrintWriter(gameLog);
            final StringBuilder sb = new StringBuilder();
            sb.append("MAGARENA GAME LOG");
            sb.append('\n');
            sb.append("CREATED ON " + (new SimpleDateFormat("yyyy/MM/dd HH:mm:ss")).format(new Date()));
            sb.append('\n');
            sb.append("MAGARENA VERSION " + MagicMain.VERSION);
            sb.append(", JRE " + System.getProperty("java.version"));
            sb.append(", OS " + System.getProperty("os.name"));
            sb.append("_" + System.getProperty("os.version"));
            sb.append(" " + System.getProperty("os.arch"));
            sb.append("\n\n");
            log(sb.toString());
        } catch (FileNotFoundException e) {
            System.err.println("Unable to create game log");
        }
    }

    public static void log(final String message) {
        if (writer != null) {
            writer.println(message);
            writer.flush();
        }
    }

    public static void close() {
        if (writer != null) {
            writer.close();
        }
    }
}