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EE4J Compatible Implementation for Jakarta Faces API
/*
* Copyright (c) 1997, 2018 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0, which is available at
* http://www.eclipse.org/legal/epl-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception, which is available at
* https://www.gnu.org/software/classpath/license.html.
*
* SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
*/
package com.sun.faces.application;
import static com.sun.faces.util.Util.isAnyNull;
import static com.sun.faces.util.Util.loadClass2;
import static com.sun.faces.util.Util.newInstance;
import java.io.Serializable;
import javax.el.ELContext;
import javax.el.ELException;
import javax.el.ValueExpression;
import javax.faces.component.StateHolder;
import javax.faces.context.FacesContext;
import javax.faces.el.ValueBinding;
/**
*
* Wrap a ValueBinding instance and expose it as a ValueExpression.
*
*/
public class ValueExpressionValueBindingAdapter extends ValueExpression implements Serializable, StateHolder {
private static final long serialVersionUID = 2990621816592041196L;
public ValueExpressionValueBindingAdapter() {
}
private ValueBinding binding = null;
public ValueExpressionValueBindingAdapter(ValueBinding binding) {
assert (null != binding);
this.binding = binding;
}
//
// Methods from ValueExpression
//
public Object getValue(ELContext context) throws ELException {
assert (null != binding);
if (context == null) {
throw new NullPointerException("ELContext -> null");
}
Object result = null;
FacesContext facesContext = (FacesContext) context.getContext(FacesContext.class);
assert (null != facesContext);
try {
result = binding.getValue(facesContext);
} catch (Throwable e) {
throw new ELException(e);
}
return result;
}
public void setValue(ELContext context, Object value) throws ELException {
assert (null != binding);
if (context == null) {
throw new NullPointerException("ELContext -> null");
}
FacesContext facesContext = (FacesContext) context.getContext(FacesContext.class);
assert (null != facesContext);
try {
binding.setValue(facesContext, value);
} catch (Throwable e) {
throw new ELException(e);
}
}
public boolean isReadOnly(ELContext context) throws ELException {
assert (null != binding);
if (context == null) {
throw new NullPointerException("ELContext -> null");
}
boolean result = false;
FacesContext facesContext = (FacesContext) context.getContext(FacesContext.class);
assert (null != facesContext);
try {
result = binding.isReadOnly(facesContext);
} catch (Throwable e) {
throw new ELException(e);
}
return result;
}
public Class getType(ELContext context) throws ELException {
assert (null != binding);
if (context == null) {
throw new NullPointerException("ELContext -> null");
}
Class result = null;
FacesContext facesContext = (FacesContext) context.getContext(FacesContext.class);
assert (null != facesContext);
try {
result = binding.getType(facesContext);
} catch (Throwable e) {
throw new ELException(e);
}
return result;
}
/**
*
* Always return false
since we can't possibly know if this is a literal text
* binding or not.
*
*/
public boolean isLiteralText() {
return false;
}
public Class getExpectedType() {
assert (null != binding);
Class result = null;
FacesContext context = FacesContext.getCurrentInstance();
try {
Object value = binding.getValue(context);
result = value.getClass();
} catch (Throwable e) {
result = null;
}
return result;
}
public String getExpressionString() {
assert (null != binding);
return binding.getExpressionString();
}
public boolean equals(Object other) {
if (other == this) {
return true;
}
if (other instanceof ValueExpressionValueBindingAdapter) {
ValueBinding vb = ((ValueExpressionValueBindingAdapter) other).getWrapped();
return (binding.equals(vb));
} else if (other instanceof ValueExpression) {
FacesContext context = FacesContext.getCurrentInstance();
ValueExpression otherVE = (ValueExpression) other;
Class type = binding.getType(context);
if (type != null) {
return type.equals(otherVE.getType(context.getELContext()));
}
}
return false;
}
public int hashCode() {
assert (null != binding);
return binding.hashCode();
}
public String getDelimiterSyntax() {
// PENDING (visvan) Implementation
return "";
}
//
// Methods from StateHolder
//
public Object saveState(FacesContext context) {
if (context == null) {
throw new NullPointerException();
}
Object result = null;
if (!tranzient) {
if (binding instanceof StateHolder) {
Object[] stateStruct = new Object[2];
// save the actual state of our wrapped binding
stateStruct[0] = ((StateHolder) binding).saveState(context);
// save the class name of the binding impl
stateStruct[1] = binding.getClass().getName();
result = stateStruct;
} else {
result = binding;
}
}
return result;
}
public void restoreState(FacesContext context, Object state) {
if (context == null) {
throw new NullPointerException();
}
if (state == null) {
return;
}
if (!(state instanceof ValueBinding)) {
Object[] stateStruct = (Object[]) state;
Object savedState = stateStruct[0];
String className = stateStruct[1].toString();
ValueBinding result = null;
if (className != null) {
Class toRestoreClass = loadClass2(className, this);
if (toRestoreClass != null) {
result = newInstance(toRestoreClass);
}
if (!isAnyNull(result, savedState)) {
// don't need to check transient, since that was
// done on the saving side.
((StateHolder) result).restoreState(context, savedState);
}
binding = result;
}
} else {
binding = (ValueBinding) state;
}
}
private boolean tranzient = false;
public boolean isTransient() {
return tranzient;
}
public void setTransient(boolean newTransientValue) {
tranzient = newTransientValue;
}
//
// methods used by classes aware of this class's wrapper nature
//
public ValueBinding getWrapped() {
return binding;
}
}