/*
* JBoss, Home of Professional Open Source
* Copyright 2011, Red Hat, Inc., and individual contributors
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* 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.jboss.seam.faces.component;
import java.io.Serializable;
import java.lang.reflect.Method;
import java.util.Arrays;
import javax.el.ELContext;
import javax.el.ELException;
import javax.el.ExpressionFactory;
import javax.el.MethodExpression;
import javax.el.MethodInfo;
import javax.el.ValueExpression;
import javax.faces.component.StateHolder;
import javax.faces.context.FacesContext;
import javax.faces.el.EvaluationException;
import javax.faces.el.MethodBinding;
import javax.faces.el.MethodNotFoundException;
/**
* <p>
* Wrap a MethodExpression instance and expose it as a MethodBinding
* </p>
*/
class MethodBindingMethodExpressionAdapter extends MethodBinding implements StateHolder, Serializable {
private static final long serialVersionUID = 7334926223014401689L;
private MethodExpression methodExpression = null;
private boolean tranzient;
public MethodBindingMethodExpressionAdapter() {
} // for StateHolder
MethodBindingMethodExpressionAdapter(final MethodExpression methodExpression) {
this.methodExpression = methodExpression;
}
@Override
@SuppressWarnings("deprecation")
public Object invoke(final FacesContext context, final Object params[]) throws EvaluationException, MethodNotFoundException {
assert (null != methodExpression);
if (context == null) {
throw new NullPointerException("FacesConext -> null");
}
Object result = null;
try {
result = methodExpression.invoke(context.getELContext(), params);
} catch (javax.el.MethodNotFoundException e) {
throw new javax.faces.el.MethodNotFoundException(e);
} catch (javax.el.PropertyNotFoundException e) {
throw new EvaluationException(e);
} catch (ELException e) {
Throwable cause = e.getCause();
if (cause == null) {
cause = e;
}
throw new EvaluationException(cause);
} catch (NullPointerException e) {
throw new MethodNotFoundException(e);
}
return result;
}
@Override
@SuppressWarnings("deprecation")
public Class<?> getType(final FacesContext context) throws MethodNotFoundException {
assert (null != methodExpression);
if (context == null) {
throw new NullPointerException("FacesConext -> null");
}
Class<?> result = null;
if (context == null) {
throw new NullPointerException();
}
try {
MethodInfo mi = methodExpression.getMethodInfo(context.getELContext());
result = mi.getReturnType();
} catch (javax.el.PropertyNotFoundException e) {
throw new MethodNotFoundException(e);
} catch (javax.el.MethodNotFoundException e) {
throw new MethodNotFoundException(e);
} catch (ELException e) {
throw new MethodNotFoundException(e);
}
return result;
}
@Override
public String getExpressionString() {
assert (null != methodExpression);
return methodExpression.getExpressionString();
}
@Override
@SuppressWarnings("deprecation")
public boolean equals(final Object other) {
if (this == other) {
return true;
}
if (other instanceof MethodBindingMethodExpressionAdapter) {
return methodExpression.equals(((MethodBindingMethodExpressionAdapter) other).getWrapped());
} else if (other instanceof MethodBinding) {
MethodBinding binding = (MethodBinding) other;
// We'll need to do a little leg work to determine
// if the MethodBinding is equivalent to the
// wrapped MethodExpression
String expr = binding.getExpressionString();
int idx = expr.indexOf('.');
String target = expr.substring(0, idx).substring(2);
String t = expr.substring(idx + 1);
String method = t.substring(0, (t.length() - 1));
FacesContext context = FacesContext.getCurrentInstance();
ELContext elContext = context.getELContext();
MethodInfo controlInfo = methodExpression.getMethodInfo(elContext);
// ensure the method names are the same
if (!controlInfo.getName().equals(method)) {
return false;
}
// Using the target, create an expression and evaluate
// it.
ExpressionFactory factory = context.getApplication().getExpressionFactory();
ValueExpression ve = factory.createValueExpression(elContext, "#{" + target + '}', Object.class);
if (ve == null) {
return false;
}
Object result = ve.getValue(elContext);
if (result == null) {
return false;
}
// Get all of the methods with the matching name and try
// to find a match based on controlInfo's return and parameter
// types
Class<?> type = binding.getType(context);
Method[] methods = result.getClass().getMethods();
for (Method meth : methods) {
if (meth.getName().equals(method) && type.equals(controlInfo.getReturnType())
&& Arrays.equals(meth.getParameterTypes(), controlInfo.getParamTypes())) {
return true;
}
}
}
return false;
}
@Override
public int hashCode() {
assert (null != methodExpression);
return methodExpression.hashCode();
}
public boolean isTransient() {
return this.tranzient;
}
public void setTransient(final boolean tranzient) {
this.tranzient = tranzient;
}
public Object saveState(final FacesContext context) {
if (context == null) {
throw new NullPointerException();
}
Object result = null;
if (!tranzient) {
if (methodExpression instanceof StateHolder) {
Object[] stateStruct = new Object[2];
// save the actual state of our wrapped methodExpression
stateStruct[0] = ((StateHolder) methodExpression).saveState(context);
// save the class name of the methodExpression impl
stateStruct[1] = methodExpression.getClass().getName();
result = stateStruct;
} else {
result = methodExpression;
}
}
return result;
}
public void restoreState(final FacesContext context, final Object state) {
if (context == null) {
throw new NullPointerException();
}
// if we have state
if (null == state) {
return;
}
if (!(state instanceof MethodExpression)) {
Object[] stateStruct = (Object[]) state;
Object savedState = stateStruct[0];
String className = stateStruct[1].toString();
MethodExpression result = null;
Class<?> toRestoreClass = null;
if (null != className) {
try {
toRestoreClass = loadClass(className, this);
} catch (ClassNotFoundException e) {
throw new IllegalStateException(e.getMessage());
}
if (null != toRestoreClass) {
try {
result = (MethodExpression) toRestoreClass.newInstance();
} catch (InstantiationException e) {
throw new IllegalStateException(e.getMessage());
} catch (IllegalAccessException a) {
throw new IllegalStateException(a.getMessage());
}
}
if ((null != result) && (null != savedState)) {
// don't need to check transient, since that was
// done on the saving side.
((StateHolder) result).restoreState(context, savedState);
}
methodExpression = result;
}
} else {
methodExpression = (MethodExpression) state;
}
}
public MethodExpression getWrapped() {
return methodExpression;
}
//
// Helper methods for StateHolder
//
private static Class<?> loadClass(final String name, final Object fallbackClass) throws ClassNotFoundException {
ClassLoader loader = Thread.currentThread().getContextClassLoader();
if (loader == null) {
loader = fallbackClass.getClass().getClassLoader();
}
return Class.forName(name, true, loader);
}
}