com.izforge.izpack.installer.requirement.JavaVersionChecker Maven / Gradle / Ivy
/*
* IzPack - Copyright 2001-2012 Julien Ponge, All Rights Reserved.
*
* http://izpack.org/
* http://izpack.codehaus.org/
*
* Copyright 2012 Tim Anderson
*
* Licensed 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 com.izforge.izpack.installer.requirement;
import com.izforge.izpack.api.data.InstallData;
import com.izforge.izpack.api.handler.Prompt;
import com.izforge.izpack.api.installer.RequirementChecker;
/**
* Verifies that the correct java version is available for installation to proceed.
*
* @author Tim Anderson
*/
public class JavaVersionChecker implements RequirementChecker
{
/**
* The installation data.
*/
private final InstallData installData;
/**
* The prompt.
*/
private final Prompt prompt;
/**
* Constructs a JavaVersionChecker.
*
* @param installData the installation data
* @param prompt the prompt
*/
public JavaVersionChecker(InstallData installData, Prompt prompt)
{
this.installData = installData;
this.prompt = prompt;
}
/**
* Checks the Java version.
*
* @return true if requirements are met, otherwise false
*/
@Override
public boolean check()
{
String version = getJavaVersion();
String required = installData.getInfo().getJavaVersion();
boolean result = required == null || version == null || version.compareTo(required) >= 0;
if (!result)
{
versionNotAvailable(version, required);
}
return result;
}
/**
* Invoked when the required java version is not available.
*
* @param version the current version
* @param requiredVersion the required version
*/
protected void versionNotAvailable(String version, String requiredVersion)
{
prompt.message(Prompt.Type.ERROR, getVersionNotAvailable(version, requiredVersion));
}
/**
* Formats a message indicating the required java version isn't available.
*
* @param version the current version
* @param requiredVersion the required version
* @return the formatted message
*/
protected String getVersionNotAvailable(String version, String requiredVersion)
{
StringBuilder msg = new StringBuilder();
msg.append("The application that you are trying to install requires a ");
msg.append(requiredVersion);
msg.append(" version or later of the Java platform.\n");
msg.append("You are running a ");
msg.append(version);
msg.append(" version of the Java platform.\n");
msg.append("Please upgrade to a newer version.");
return msg.toString();
}
/**
* Returns the java version.
*
* @return the java version, as determined by the java.version system property
*/
protected String getJavaVersion()
{
return System.getProperty("java.version");
}
}