/*
* Copyright 2002-2010 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.expression.spel.support;
import java.lang.reflect.Method;
import org.springframework.core.MethodParameter;
import org.springframework.core.convert.TypeDescriptor;
import org.springframework.expression.AccessException;
import org.springframework.expression.EvaluationContext;
import org.springframework.expression.MethodExecutor;
import org.springframework.expression.TypedValue;
import org.springframework.util.ReflectionUtils;
/**
* @author Andy Clement
* @author Juergen Hoeller
* @since 3.0
*/
class ReflectiveMethodExecutor implements MethodExecutor {
private final Method method;
private final Integer varargsPosition;
// When the method was found, we will have determined if arguments need to be converted for it
// to be invoked. Conversion won't be cheap so let's only do it if necessary.
private final int[] argsRequiringConversion;
public ReflectiveMethodExecutor(Method theMethod, int[] argumentsRequiringConversion) {
this.method = theMethod;
if (theMethod.isVarArgs()) {
Class[] paramTypes = theMethod.getParameterTypes();
this.varargsPosition = paramTypes.length - 1;
}
else {
this.varargsPosition = null;
}
this.argsRequiringConversion = argumentsRequiringConversion;
}
public TypedValue execute(EvaluationContext context, Object target, Object... arguments) throws AccessException {
try {
if (arguments != null) {
ReflectionHelper.convertArguments(
context.getTypeConverter(), arguments, this.method,
this.argsRequiringConversion, this.varargsPosition);
}
if (this.method.isVarArgs()) {
arguments = ReflectionHelper.setupArgumentsForVarargsInvocation(this.method.getParameterTypes(), arguments);
}
ReflectionUtils.makeAccessible(this.method);
Object value = this.method.invoke(target, arguments);
return new TypedValue(value, new TypeDescriptor(new MethodParameter(this.method, -1)).narrow(value));
}
catch (Exception ex) {
throw new AccessException("Problem invoking method: " + this.method, ex);
}
}
}