// Copyright 2004, 2005 The Apache Software Foundation
//
// 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 org.apache.tapestry.bean;
import java.lang.reflect.Field;
import org.apache.hivemind.ApplicationRuntimeException;
import org.apache.hivemind.ClassResolver;
import org.apache.tapestry.IBeanProvider;
import org.apache.tapestry.Tapestry;
/**
* Initializes a bean with the value of a public static field.
*
* @author Howard Lewis Ship
* @since 1.0.8
*
**/
public class FieldBeanInitializer extends AbstractBeanInitializer
{
protected String _fieldName;
protected Object _fieldValue;
private boolean _fieldResolved = false;
public synchronized void setBeanProperty(IBeanProvider provider, Object bean)
{
ClassResolver resolver = provider.getClassResolver();
if (!_fieldResolved)
resolveField(resolver);
setBeanProperty(bean, _fieldValue);
}
private void resolveField(ClassResolver resolver)
{
if (_fieldResolved)
return;
// This is all copied out of of FieldBinding!!
int dotx = _fieldName.lastIndexOf('.');
if (dotx < 0)
throw new ApplicationRuntimeException(
Tapestry.format("invalid-field-name", _fieldName));
String className = _fieldName.substring(0, dotx);
String simpleFieldName = _fieldName.substring(dotx + 1);
// Simple class names are assumed to be in the java.lang package.
if (className.indexOf('.') < 0)
className = "java.lang." + className;
Class targetClass = null;
try
{
targetClass = resolver.findClass(className);
}
catch (Throwable t)
{
throw new ApplicationRuntimeException(
Tapestry.format("unable-to-resolve-class", className),
t);
}
Field field = null;
try
{
field = targetClass.getField(simpleFieldName);
}
catch (NoSuchFieldException ex)
{
throw new ApplicationRuntimeException(
Tapestry.format("field-not-defined", _fieldName),
ex);
}
// Get the value of the field. null means look for it as a static
// variable.
try
{
_fieldValue = field.get(null);
}
catch (IllegalAccessException ex)
{
throw new ApplicationRuntimeException(
Tapestry.format("illegal-field-access", _fieldName),
ex);
}
catch (NullPointerException ex)
{
throw new ApplicationRuntimeException(
Tapestry.format("field-is-instance", _fieldName),
ex);
}
_fieldResolved = true;
}
}