infra.beans.support.ArgumentConvertingMethodInvoker Maven / Gradle / Ivy
/*
* Copyright 2017 - 2024 the original author or authors.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see [https://www.gnu.org/licenses/]
*/
package infra.beans.support;
import java.beans.PropertyEditor;
import java.lang.reflect.Method;
import infra.beans.BeanWrapperImpl;
import infra.beans.PropertyEditorRegistry;
import infra.beans.SimpleTypeConverter;
import infra.beans.TypeConverter;
import infra.beans.TypeMismatchException;
import infra.lang.Assert;
import infra.lang.Nullable;
import infra.util.ReflectionUtils;
import infra.util.ReflectiveMethodInvoker;
/**
* Subclass of {@link ReflectiveMethodInvoker} that tries to convert the given
* arguments for the actual target method via a {@link TypeConverter}.
*
* Supports flexible argument conversions, in particular for
* invoking a specific overloaded method.
*
* @author Juergen Hoeller
* @author Harry Yang
* @see BeanWrapperImpl#convertIfNecessary
* @since 4.0 2022/2/18 11:12
*/
public class ArgumentConvertingMethodInvoker extends ReflectiveMethodInvoker {
@Nullable
private TypeConverter typeConverter;
private boolean useDefaultConverter = true;
/**
* Set a TypeConverter to use for argument type conversion.
*
Default is a {@link SimpleTypeConverter}.
* Can be overridden with any TypeConverter implementation, typically
* a pre-configured SimpleTypeConverter or a BeanWrapperImpl instance.
*
* @see SimpleTypeConverter
* @see BeanWrapperImpl
*/
public void setTypeConverter(@Nullable TypeConverter typeConverter) {
this.typeConverter = typeConverter;
this.useDefaultConverter = (typeConverter == null);
}
/**
* Return the TypeConverter used for argument type conversion.
*
Can be cast to {@link PropertyEditorRegistry}
* if direct access to the underlying PropertyEditors is desired
* (provided that the present TypeConverter actually implements the
* PropertyEditorRegistry interface).
*/
@Nullable
public TypeConverter getTypeConverter() {
if (this.typeConverter == null && this.useDefaultConverter) {
this.typeConverter = getDefaultTypeConverter();
}
return this.typeConverter;
}
/**
* Obtain the default TypeConverter for this method invoker.
*
Called if no explicit TypeConverter has been specified.
* The default implementation builds a
* {@link SimpleTypeConverter}.
* Can be overridden in subclasses.
*/
protected TypeConverter getDefaultTypeConverter() {
return new SimpleTypeConverter();
}
/**
* Register the given custom property editor for all properties of the given type.
*
Typically used in conjunction with the default
* {@link SimpleTypeConverter}; will work with any
* TypeConverter that implements the PropertyEditorRegistry interface as well.
*
* @param requiredType type of the property
* @param propertyEditor editor to register
* @see #setTypeConverter
* @see PropertyEditorRegistry#registerCustomEditor
*/
public void registerCustomEditor(Class requiredType, PropertyEditor propertyEditor) {
TypeConverter converter = getTypeConverter();
if (!(converter instanceof PropertyEditorRegistry)) {
throw new IllegalStateException(
"TypeConverter does not implement PropertyEditorRegistry interface: " + converter);
}
((PropertyEditorRegistry) converter).registerCustomEditor(requiredType, propertyEditor);
}
/**
* This implementation looks for a method with matching parameter types.
*
* @see #doFindMatchingMethod
*/
@Override
protected Method findMatchingMethod() {
Method matchingMethod = super.findMatchingMethod();
// Second pass: look for method where arguments can be converted to parameter types.
if (matchingMethod == null) {
// Interpret argument array as individual method arguments.
matchingMethod = doFindMatchingMethod(getArguments());
}
if (matchingMethod == null) {
// Interpret argument array as single method argument of array type.
matchingMethod = doFindMatchingMethod(new Object[] { getArguments() });
}
return matchingMethod;
}
/**
* Actually find a method with matching parameter type, i.e. where each
* argument value is assignable to the corresponding parameter type.
*
* @param arguments the argument values to match against method parameters
* @return a matching method, or {@code null} if none
*/
@Nullable
protected Method doFindMatchingMethod(Object[] arguments) {
TypeConverter converter = getTypeConverter();
if (converter != null) {
String targetMethod = getTargetMethod();
Method matchingMethod = null;
int argCount = arguments.length;
Class targetClass = getTargetClass();
Assert.state(targetClass != null, "No target class set");
Method[] candidates = ReflectionUtils.getAllDeclaredMethods(targetClass);
int minTypeDiffWeight = Integer.MAX_VALUE;
Object[] argumentsToUse = null;
for (Method candidate : candidates) {
if (candidate.getName().equals(targetMethod)) {
// Check if the inspected method has the correct number of parameters.
int parameterCount = candidate.getParameterCount();
if (parameterCount == argCount) {
Class[] paramTypes = candidate.getParameterTypes();
Object[] convertedArguments = new Object[argCount];
boolean match = true;
for (int j = 0; j < argCount && match; j++) {
// Verify that the supplied argument is assignable to the method parameter.
try {
convertedArguments[j] = converter.convertIfNecessary(arguments[j], paramTypes[j]);
}
catch (TypeMismatchException ex) {
// Ignore -> simply doesn't match.
match = false;
}
}
if (match) {
int typeDiffWeight = getTypeDifferenceWeight(paramTypes, convertedArguments);
if (typeDiffWeight < minTypeDiffWeight) {
minTypeDiffWeight = typeDiffWeight;
matchingMethod = candidate;
argumentsToUse = convertedArguments;
}
}
}
}
}
if (matchingMethod != null) {
setArguments(argumentsToUse);
return matchingMethod;
}
}
return null;
}
}