/*
* Copyright 2006 The Apache Software Foundation.
*
* 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 javax.faces.component;
import javax.el.ELContext;
import javax.el.ELException;
import javax.el.MethodExpression;
import javax.el.MethodInfo;
import javax.el.MethodNotFoundException;
import javax.el.PropertyNotFoundException;
import javax.faces.context.FacesContext;
import javax.faces.el.EvaluationException;
import javax.faces.el.MethodBinding;
/**
* Converts a MethodBinding to a MethodExpression
*
* TODO: find a way to share the implementation of class with impl.
*
* @author Stan Silvert
*/
@SuppressWarnings("deprecation")
class _MethodBindingToMethodExpression extends MethodExpression implements StateHolder
{
private static final Class[] EXPECTED_TYPES = new Class[] { MethodBinding.class, StateHolder.class };
private MethodBinding methodBinding;
private boolean _transientFlag;
private transient MethodInfo methodInfo;
/**
* No-arg constructor used during restoreState
*/
protected _MethodBindingToMethodExpression()
{
}
/** Creates a new instance of MethodBindingToMethodExpression */
public _MethodBindingToMethodExpression(MethodBinding methodBinding)
{
checkNullArgument(methodBinding, "methodBinding");
this.methodBinding = methodBinding;
}
/**
* Return the wrapped MethodBinding.
*/
public MethodBinding getMethodBinding()
{
return methodBinding;
}
void setMethodBinding(MethodBinding methodBinding)
{
this.methodBinding = methodBinding;
}
/**
* Note: MethodInfo.getParamTypes() may incorrectly return an empty class array if invoke() has not been called.
*
* @throws IllegalStateException
* if expected params types have not been determined.
*/
public MethodInfo getMethodInfo(ELContext context) throws PropertyNotFoundException, MethodNotFoundException,
ELException
{
checkNullArgument(context, "elcontext");
checkNullState(methodBinding, "methodBinding");
if (methodInfo == null)
{
final FacesContext facesContext = (FacesContext) context.getContext(FacesContext.class);
if (facesContext != null)
{
methodInfo = invoke(new Invoker<MethodInfo>()
{
public MethodInfo invoke()
{
return new MethodInfo(null, methodBinding.getType(facesContext), null);
}
});
}
}
return methodInfo;
}
public Object invoke(ELContext context, final Object[] params) throws PropertyNotFoundException,
MethodNotFoundException, ELException
{
checkNullArgument(context, "elcontext");
checkNullState(methodBinding, "methodBinding");
final FacesContext facesContext = (FacesContext) context.getContext(FacesContext.class);
if (facesContext != null)
{
return invoke(new Invoker<Object>()
{
public Object invoke()
{
return methodBinding.invoke(facesContext, params);
}
});
}
return null;
}
public boolean isLiteralText()
{
if (methodBinding == null)
throw new IllegalStateException("methodBinding is null");
String expr = methodBinding.getExpressionString();
return !(expr.startsWith("#{") && expr.endsWith("}"));
}
public String getExpressionString()
{
return methodBinding.getExpressionString();
}
public Object saveState(FacesContext context)
{
if (!isTransient())
{
if (methodBinding instanceof StateHolder)
{
Object[] state = new Object[2];
state[0] = methodBinding.getClass().getName();
state[1] = ((StateHolder) methodBinding).saveState(context);
return state;
}
else
{
return methodBinding;
}
}
return null;
}
public void restoreState(FacesContext context, Object state)
{
if (state instanceof MethodBinding)
{
methodBinding = (MethodBinding) state;
methodInfo = null;
}
else if (state != null)
{
Object[] values = (Object[]) state;
methodBinding = (MethodBinding) _ClassUtils.newInstance(values[0].toString(), EXPECTED_TYPES);
((StateHolder) methodBinding).restoreState(context, values[1]);
methodInfo = null;
}
}
public void setTransient(boolean transientFlag)
{
_transientFlag = transientFlag;
}
public boolean isTransient()
{
return _transientFlag;
}
@Override
public int hashCode()
{
final int PRIME = 31;
int result = 1;
result = PRIME * result + ((methodBinding == null) ? 0 : methodBinding.hashCode());
return result;
}
@Override
public boolean equals(Object obj)
{
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
final _MethodBindingToMethodExpression other = (_MethodBindingToMethodExpression) obj;
if (methodBinding == null)
{
if (other.methodBinding != null)
return false;
}
else if (!methodBinding.equals(other.methodBinding))
return false;
return true;
}
private void checkNullState(Object notNullInstance, String instanceName)
{
if (notNullInstance == null)
throw new IllegalStateException(instanceName + " is null");
}
private void checkNullArgument(Object notNullInstance, String instanceName)
{
if (notNullInstance == null)
throw new IllegalArgumentException(instanceName + " is null");
}
private <T> T invoke(Invoker<T> invoker)
{
try
{
return invoker.invoke();
}
catch (javax.faces.el.MethodNotFoundException e)
{
throw new MethodNotFoundException(e.getMessage(), e);
}
catch (EvaluationException e)
{
throw new ELException(e.getMessage(), e);
}
}
private interface Invoker<T>
{
T invoke();
}
}