net.sf.jasperreports.engine.util.ClassUtils Maven / Gradle / Ivy
/*
* JasperReports - Free Java Reporting Library.
* Copyright (C) 2001 - 2013 Jaspersoft Corporation. All rights reserved.
* http://www.jaspersoft.com
*
* Unless you have purchased a commercial license agreement from Jaspersoft,
* the following license terms apply:
*
* This program is part of JasperReports.
*
* JasperReports is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* JasperReports 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with JasperReports. If not, see .
*/
package net.sf.jasperreports.engine.util;
import net.sf.jasperreports.engine.JRRuntimeException;
/**
* Class utilities.
*
* @author Lucian Chirita ([email protected])
* @version $Id: ClassUtils.java 5878 2013-01-07 20:23:13Z teodord $
*/
public final class ClassUtils
{
/**
* Instantiates a class.
*
*
* The class is expected to have a public no-argument constructor.
*
* @param className the class name
* @param expectedType the expected (super) type of the result
* @return a newly created instance of the specified class
* @throws JRRuntimeException if the class cannot be loaded or instantiated,
* or if it does not implement the expected type
*/
public static final Object instantiateClass(String className, Class expectedType)
{
try
{
Class clazz = JRClassLoader.loadClassForName(className);
if (!expectedType.isAssignableFrom(clazz))
{
throw new JRRuntimeException("Class " + className
+ " does not implement/extend " + expectedType.getName());
}
return clazz.newInstance();
}
catch (ClassNotFoundException e)
{
throw new JRRuntimeException(
"Could not load class " + className, e);
}
catch (InstantiationException e)
{
throw new JRRuntimeException(
"Could not instantiate class " + className, e);
}
catch (IllegalAccessException e)
{
throw new JRRuntimeException(
"Could not instantiate class " + className, e);
}
}
private ClassUtils()
{
}
}