/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.jxpath.functions;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import org.apache.commons.jxpath.ExpressionContext;
import org.apache.commons.jxpath.Function;
import org.apache.commons.jxpath.JXPathInvalidAccessException;
import org.apache.commons.jxpath.util.TypeUtils;
import org.apache.commons.jxpath.util.ValueUtils;
/**
* An XPath extension function implemented as an individual Java method.
*
* @author Dmitri Plotnikov
* @version $Revision: 652845 $ $Date: 2008-05-02 12:46:46 -0500 (Fri, 02 May 2008) $
*/
public class MethodFunction implements Function {
private Method method;
private static final Object[] EMPTY_ARRAY = new Object[0];
/**
* Create a new MethodFunction.
* @param method implementing Method
*/
public MethodFunction(Method method) {
this.method = ValueUtils.getAccessibleMethod(method);
}
public Object invoke(ExpressionContext context, Object[] parameters) {
try {
Object target;
Object[] args;
if (Modifier.isStatic(method.getModifiers())) {
target = null;
if (parameters == null) {
parameters = EMPTY_ARRAY;
}
int pi = 0;
Class[] types = method.getParameterTypes();
if (types.length >= 1
&& ExpressionContext.class.isAssignableFrom(types[0])) {
pi = 1;
}
args = new Object[parameters.length + pi];
if (pi == 1) {
args[0] = context;
}
for (int i = 0; i < parameters.length; i++) {
args[i + pi] =
TypeUtils.convert(parameters[i], types[i + pi]);
}
}
else {
int pi = 0;
Class[] types = method.getParameterTypes();
if (types.length >= 1
&& ExpressionContext.class.isAssignableFrom(types[0])) {
pi = 1;
}
target =
TypeUtils.convert(
parameters[0],
method.getDeclaringClass());
args = new Object[parameters.length - 1 + pi];
if (pi == 1) {
args[0] = context;
}
for (int i = 1; i < parameters.length; i++) {
args[pi + i - 1] =
TypeUtils.convert(parameters[i], types[i + pi - 1]);
}
}
return method.invoke(target, args);
}
catch (Throwable ex) {
if (ex instanceof InvocationTargetException) {
ex = ((InvocationTargetException) ex).getTargetException();
}
throw new JXPathInvalidAccessException("Cannot invoke " + method,
ex);
}
}
public String toString() {
return method.toString();
}
}
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