/*
* 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.shale.test.el;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;
import javax.el.ELContext;
import javax.el.ELException;
import javax.el.ELResolver;
import javax.el.MethodExpression;
import javax.el.MethodInfo;
import javax.faces.context.FacesContext;
/**
* <p>Mock implementation of <code>MethodExpression</code>.</p>
*/
public class MockMethodExpression extends MethodExpression {
// ------------------------------------------------------------ Constructors
/**
* Serial version UID.
*/
private static final long serialVersionUID = 5694105394290316715L;
/**
* <p>Construct a new expression for the specified expression string.</p>
*
* @param expression Expression string to be evaluated
* @param signature Parameter signature of the method to be called
* @param expectedType Expected type of the result
*/
public MockMethodExpression(String expression, Class[] signature, Class expectedType) {
if (expression == null) {
throw new NullPointerException("Expression string cannot be null");
}
this.expression = expression;
this.signature = signature;
this.expectedType = expectedType;
parse();
}
// ------------------------------------------------------ Instance Variables
/**
* <p>The parsed elements of this expression.</p>
*/
private String[] elements = null;
/**
* <p>The expected result type for <code>getValue()</code> calls.</p>
*/
private Class expectedType = null;
/**
* <p>The original expression string used to create this expression.</p>
*/
private String expression = null;
/**
* <p>The method signature of the method to be called.</p>
*/
private Class[] signature = null;
// ------------------------------------------------------ Expression Methods
/**
* <p>Return <code>true</code> if this expression is equal to the
* specified expression.</p>
*
* @param obj Object to be compared
*/
public boolean equals(Object obj) {
if ((obj != null) & (obj instanceof MethodExpression)) {
return expression.equals(((MethodExpression) obj).getExpressionString());
} else {
return false;
}
}
/**
* <p>Return the original String used to create this expression,
* unmodified.</p>
*/
public String getExpressionString() {
return this.expression;
}
/**
* <p>Return the hash code for this expression.</p>
*/
public int hashCode() {
return this.expression.hashCode();
}
/**
* <p>Return <code>true</code> if the expression string for this expression
* contains only literal text.</p>
*/
public boolean isLiteralText() {
return (expression.indexOf("${") < 0) && (expression.indexOf("#{") < 0);
}
// ------------------------------------------------ MethodExpression Methods
/**
* <p>Evaluate the expression relative to the specified context,
* and return information about the actual implementation method.</p>
*
* @param context ELContext for this evaluation
*/
public MethodInfo getMethodInfo(ELContext context) {
if (context == null) {
throw new NullPointerException();
}
return new MethodInfo(elements[elements.length - 1], expectedType, signature);
}
/**
* <p>Evaluate the expression relative to the specified ocntext,
* and return the result after coercion to the expected result type.</p>
*
* @param context ELContext for this evaluation
* @param params Parameters for this method call
*/
public Object invoke(ELContext context, Object[] params) {
if (context == null) {
throw new NullPointerException();
}
if (isLiteralText()) {
return expression;
}
FacesContext fcontext = (FacesContext) context.getContext(FacesContext.class);
ELResolver resolver = fcontext.getApplication().getELResolver();
Object base = null;
for (int i = 0; i < elements.length - 1; i++) {
base = resolver.getValue(context, base, elements[i]);
}
try {
Method method = base.getClass().getMethod(elements[elements.length - 1], signature);
Object result = method.invoke(base, params);
return fcontext.getApplication().getExpressionFactory().coerceToType(result, expectedType);
} catch (RuntimeException e) {
throw e;
} catch (Exception e) {
throw new ELException(e);
}
}
// --------------------------------------------------------- Private Methods
/**
* <p>Parse the expression string into its constituent elemetns.</p>
*/
private void parse() {
if (isLiteralText()) {
elements = new String[0];
return;
}
if (expression.startsWith("${") || expression.startsWith("#{")) {
if (expression.endsWith("}")) {
String temp = expression.substring(2, expression.length() - 1).replaceAll(" ", "");
List names = new ArrayList();
while (temp.length() > 0) {
int period= temp.indexOf(".");
if (period >= 0) {
names.add(temp.substring(0, period));
temp = temp.substring(period + 1);
} else {
names.add(temp);
temp = "";
}
}
elements = (String[]) names.toArray(new String[names.size()]);
} else {
throw new IllegalArgumentException(expression);
}
} else {
throw new IllegalArgumentException(expression);
}
}
}