rdonkin 2004/12/01 11:33:48
Added: betwixt/src/java/org/apache/commons/betwixt/expression
TypedUpdater.java
Log:
Improved introspection support for dynabeans
Revision Changes Path
1.1
jakarta-commons/betwixt/src/java/org/apache/commons/betwixt/expression/TypedUpdater.java
Index: TypedUpdater.java
===================================================================
/*
* Copyright 2004 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.commons.betwixt.expression;
import java.lang.reflect.Array;
import java.util.Collection;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* Abstracts common features for strongly typed <code>Updater</code>'s.
* Strongly type <code>Updater</code>'s perform conversions based on this
* the expected type before the bean update is invoked.
* @author <a href='http://jakarta.apache.org/commons'>Jakarta Commons
Team</a>, <a href='http://www.apache.org'>Apache Software Foundation</a>
*/
public abstract class TypedUpdater implements Updater {
/** Logger */
private static final Log log = LogFactory.getLog( TypedUpdater.class );
/** The type of the first parameter of the method */
private Class valueType;
/**
* Updates the current bean context with the given String value
* @param context the Context to be updated
* @param newValue the update to this new value
*/
public void update(Context context, Object newValue) {
Object bean = context.getBean();
if ( bean != null ) {
if ( newValue instanceof String ) {
// try to convert into primitive types
if ( log.isTraceEnabled() ) {
log.trace("Converting primitive to " + valueType);
}
newValue = context.getObjectStringConverter()
.stringToObject( (String) newValue, valueType, null,
context );
}
if ( newValue != null ) {
// check that it is of the correct type
/*
if ( ! valueType.isAssignableFrom( newValue.getClass() )
) {
log.warn(
"Cannot call setter method: " + method.getName()
+ " on bean: " + bean
+ " with type: " + bean.getClass().getName()
+ " as parameter should be of type: " +
valueType.getName()
+ " but is: " + newValue.getClass().getName()
);
return;
}
*/
}
// special case for collection objects into arrays
if (newValue instanceof Collection && valueType.isArray()) {
Collection valuesAsCollection = (Collection) newValue;
Class componentType = valueType.getComponentType();
if (componentType != null) {
Object[] valuesAsArray =
(Object[]) Array.newInstance(componentType,
valuesAsCollection.size());
newValue = valuesAsCollection.toArray(valuesAsArray);
}
}
;
try {
executeUpdate( context, bean, newValue );
} catch (Exception e) {
String valueTypeName = (newValue != null) ?
newValue.getClass().getName() : "null";
log.warn(
"Cannot evaluate: " + this.toString() + " on bean: "
+ bean
+ " of type: " + bean.getClass().getName() + " with
value: " + newValue
+ " of type: " + valueTypeName
);
handleException(context, e);
}
}
}
/**
* Gets the type expected.
* The value passed into [EMAIL PROTECTED] #update}
* will be converted on the basis of this type
* before being passed to [EMAIL PROTECTED] #executeUpdate}.
* @return <code>Class</code> giving expected type, not null
*/
public Class getValueType() {
return valueType;
}
/**
* Sets the type expected.
* The value passed into [EMAIL PROTECTED] #update}
* will be converted on the basis of this type
* before being passed to [EMAIL PROTECTED] #executeUpdate}.
* @param valueType <code>Class</code> giving expected type, not null
*/
public void setValueType(Class valueType) {
this.valueType = valueType;
}
/**
* Updates the bean with the given value.
* @param bean
* @param value value after type conversion
*/
protected abstract void executeUpdate(Context context, Object bean,
Object value) throws Exception;
/**
* Strategy method to allow derivations to handle exceptions differently.
* @param context the Context being updated when this exception occured
* @param e the Exception that occured during the update
*/
protected void handleException(Context context, Exception e) {
log.info( "Caught exception: " + e, e );
}
}
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
