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/*
* Copyright 2002-2009 the original author or authors.
*
* 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 net.sf.json.util;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import net.sf.json.JSONObject;
/**
* Base class for creating Bean instances.
*
* - DEFAULT - calls Class.newInstance().
*
*
* @author Andres Almiray
*/
public abstract class NewBeanInstanceStrategy {
/** Calls Class.newInstance() */
public static final NewBeanInstanceStrategy DEFAULT = new DefaultNewBeanInstanceStrategy();
/**
* Creates a new instance.
*
* @param target
* the source class
* @param source
* additional properties that may be needed to create the instance
*/
public abstract Object newInstance(Class target, JSONObject source) throws InstantiationException,
IllegalAccessException, SecurityException, NoSuchMethodException, InvocationTargetException;
private static final class DefaultNewBeanInstanceStrategy extends NewBeanInstanceStrategy {
private static final Object[] EMPTY_ARGS = new Object[0];
private static final Class[] EMPTY_PARAM_TYPES = new Class[0];
public Object newInstance(Class target, JSONObject source) throws InstantiationException,
IllegalAccessException, SecurityException, NoSuchMethodException, InvocationTargetException {
if (target != null) {
Constructor c = target.getDeclaredConstructor(EMPTY_PARAM_TYPES);
c.setAccessible(true);
try {
return c.newInstance(EMPTY_ARGS);
} catch (InstantiationException e) {
// getCause() was added on jdk 1.4
String cause = "";
try {
cause = e.getCause() != null ? "\n" + e.getCause().getMessage() : "";
} catch (Throwable t) {
/* ignore */ }
throw new InstantiationException("Instantiation of \"" + target + "\" failed. "
+ "It's probably because class is an interface, "
+ "abstract class, array class, primitive type or void." + cause);
}
}
return null;
}
}
}