org.springframework.beans.support.ArgumentConvertingMethodInvoker Maven / Gradle / Ivy
/*
* Copyright 2002-2005 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.springframework.beans.support;
import java.beans.PropertyEditor;
import java.lang.reflect.Method;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.BeanWrapperImpl;
import org.springframework.beans.TypeMismatchException;
import org.springframework.util.MethodInvoker;
/**
* Subclass of MethodInvoker that tries to convert the given arguments
* for the actual target method via BeanWrapperImpl.
*
* Supports flexible argument conversions, in particular for
* invoking a specific overloaded method.
*
* @author Juergen Hoeller
* @since 1.1
* @see org.springframework.beans.BeanWrapperImpl#doTypeConversionIfNecessary
*/
public class ArgumentConvertingMethodInvoker extends MethodInvoker {
private final BeanWrapperImpl beanWrapper = new BeanWrapperImpl();
/**
* Register the given custom property editor for all properties
* of the given type.
* @param requiredType type of the property
* @param propertyEditor editor to register
* @see org.springframework.beans.BeanWrapper#registerCustomEditor
*/
public void registerCustomEditor(Class requiredType, PropertyEditor propertyEditor) {
this.beanWrapper.registerCustomEditor(requiredType, propertyEditor);
}
/**
* This implementation looks for a method with matching parameter types:
* that is, where each argument value is assignable to the corresponding parameter type.
*/
protected Method findMatchingMethod() {
Method[] candidates = getTargetClass().getMethods();
Object[] arguments = getArguments();
int argCount = arguments.length;
// First pass: look for method with directly assignable arguments.
for (int i = 0; i < candidates.length; i++) {
if (candidates[i].getName().equals(getTargetMethod())) {
// Check if the inspected method has the correct number of parameters.
Class[] paramTypes = candidates[i].getParameterTypes();
if (paramTypes.length == argCount) {
int numberOfCorrectArguments = 0;
for (int j = 0; j < argCount; j++) {
// Verify that the supplied argument is assignable to the method parameter.
if (BeanUtils.isAssignable(paramTypes[j], arguments[j])) {
numberOfCorrectArguments++;
}
}
if (numberOfCorrectArguments == argCount) {
return candidates[i];
}
}
}
}
// Second pass: look for method where arguments can be converted to parameter types.
for (int i = 0; i < candidates.length; i++) {
if (candidates[i].getName().equals(getTargetMethod())) {
// Check if the inspected method has the correct number of parameters.
Class[] paramTypes = candidates[i].getParameterTypes();
if (paramTypes.length == argCount) {
Object[] argumentsToUse = arguments;
int numberOfCorrectArguments = 0;
for (int j = 0; j < argCount; j++) {
// Verify that the supplied argument is assignable to the method parameter.
try {
argumentsToUse[j] = this.beanWrapper.doTypeConversionIfNecessary(arguments[j], paramTypes[j]);
numberOfCorrectArguments++;
}
catch (TypeMismatchException ex) {
// Ignore -> simply doesn't match.
}
}
if (numberOfCorrectArguments == argumentsToUse.length) {
setArguments(argumentsToUse);
return candidates[i];
}
}
}
}
return null;
}
}