/*
Violet - A program for editing UML diagrams.
Copyright (C) 2002 Cay S. Horstmann (http://horstmann.com)
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 2 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, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package com.horstmann.violet.framework;
import java.text.MessageFormat;
import java.util.ResourceBundle;
import java.util.StringTokenizer;
import javax.swing.JOptionPane;
/**
Checks if the Java version of the current VM is at
least a given version.
*/
public class VersionChecker
{
/**
Checks if the current VM has at least the given
version, and exits the program with an error dialog if not.
@param desiredVersion the desired version
*/
public void check(String desiredVersion)
{
String actualVersion = System.getProperty("java.version");
boolean versionOk;
try
{
versionOk = versionCompare(actualVersion,
desiredVersion) >= 0;
}
catch (NumberFormatException exception)
{
versionOk = false;
}
if (!versionOk)
{
ResourceBundle resources =
ResourceBundle.getBundle(RESOURCE_NAME);
String versionError = resources.getString("error.version");
MessageFormat formatter = new MessageFormat(versionError);
String message = formatter.format(new Object[] { desiredVersion } );
JOptionPane.showMessageDialog(null, message);
System.exit(1);
}
}
public static int versionCompare(String v1,
String v2)
{
StringTokenizer t1 = new StringTokenizer(v1, "._");
StringTokenizer t2 = new StringTokenizer(v2, "._");
while (t1.hasMoreTokens())
{
if (!t2.hasMoreTokens()) return 1;
int n1 = Integer.parseInt(t1.nextToken());
int n2 = Integer.parseInt(t2.nextToken());
int d = n1 - n2;
if (d != 0) return d;
}
return t2.hasMoreTokens() ? -1 : 0;
}
private String RESOURCE_NAME
= "com.horstmann.violet.framework.EditorStrings";
}