/*
* Copyright 2004-2005 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 org.springmodules.validation.util.fel.parser;
import org.springframework.beans.BeanWrapperImpl;
import org.springmodules.validation.util.fel.FelEvaluationException;
import org.springmodules.validation.util.fel.Function;
import org.springmodules.validation.util.fel.FunctionExpressionParser;
/**
* A {@link FunctionExpressionParser} implementation that knows how to parse BeanWrapper-like property paths and
* returns a function that extracts the appropriate property value from the given object (bean).
*
* @author Uri Boness
*/
public class PropertyPathFunctionExpressionParser implements FunctionExpressionParser {
public Function parse(String expression) {
return new PropertyPathFunction(expression);
}
/**
* A function that is associated with a property path. On evaluation, the appropriate property value is
* extracted from the given object (bean).
*/
protected class PropertyPathFunction implements Function {
private String propertyPath;
public PropertyPathFunction(String propertyPath) {
this.propertyPath = propertyPath;
}
public Object evaluate(Object argument) {
try {
return new BeanWrapperImpl(argument).getPropertyValue(propertyPath);
} catch (Throwable t) {
throw new FelEvaluationException("Could not evaluate path '" + propertyPath +
"' on bean '" + String.valueOf(argument) + "'", t);
}
}
}
}