camundafeel.de.odysseus.el.tree.Bindings Maven / Gradle / Ivy
/*
* Copyright 2006-2009 Odysseus Software GmbH
*
* 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 de.odysseus.el.tree;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.lang.reflect.Method;
import java.util.Arrays;
import javax.el.ELException;
import javax.el.ValueExpression;
import de.odysseus.el.misc.TypeConverter;
/**
* Bindings, usually created by a {@link de.odysseus.el.tree.Tree}.
*
* @author Christoph Beck
*/
public class Bindings implements TypeConverter {
private static final long serialVersionUID = 1L;
private static final Method[] NO_FUNCTIONS = new Method[0];
private static final ValueExpression[] NO_VARIABLES = new ValueExpression[0];
/**
* Wrap a {@link Method} for serialization.
*/
private static class MethodWrapper implements Serializable {
private static final long serialVersionUID = 1L;
private transient Method method;
private MethodWrapper(Method method) {
this.method = method;
}
private void writeObject(ObjectOutputStream out) throws IOException, ClassNotFoundException {
out.defaultWriteObject();
out.writeObject(method.getDeclaringClass());
out.writeObject(method.getName());
out.writeObject(method.getParameterTypes());
}
private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
in.defaultReadObject();
Class type = (Class)in.readObject();
String name = (String)in.readObject();
Class[] args = (Class[])in.readObject();
try {
method = type.getDeclaredMethod(name, args);
} catch (NoSuchMethodException e) {
throw new IOException(e.getMessage());
}
}
}
private transient Method[] functions;
private final ValueExpression[] variables;
private final TypeConverter converter;
/**
* Constructor.
*/
public Bindings(Method[] functions, ValueExpression[] variables) {
this(functions, variables, TypeConverter.DEFAULT);
}
/**
* Constructor.
*/
public Bindings(Method[] functions, ValueExpression[] variables, TypeConverter converter) {
super();
this.functions = functions == null || functions.length == 0 ? NO_FUNCTIONS : functions;
this.variables = variables == null || variables.length == 0 ? NO_VARIABLES : variables;
this.converter = converter == null ? TypeConverter.DEFAULT : converter;
}
/**
* Get function by index.
* @param index function index
* @return method
*/
public Method getFunction(int index) {
return functions[index];
}
/**
* Test if given index is bound to a function.
* This method performs an index check.
* @param index identifier index
* @return true if the given index is bound to a function
*/
public boolean isFunctionBound(int index) {
return index >= 0 && index < functions.length;
}
/**
* Get variable by index.
* @param index identifier index
* @return value expression
*/
public ValueExpression getVariable(int index) {
return variables[index];
}
/**
* Test if given index is bound to a variable.
* This method performs an index check.
* @param index identifier index
* @return true if the given index is bound to a variable
*/
public boolean isVariableBound(int index) {
return index >= 0 && index < variables.length && variables[index] != null;
}
/**
* Apply type conversion.
* @param value value to convert
* @param type target type
* @return converted value
* @throws ELException
*/
public T convert(Object value, Class type) {
return converter.convert(value, type);
}
@Override
public boolean equals(Object obj) {
if (obj instanceof Bindings) {
Bindings other = (Bindings)obj;
return Arrays.equals(functions, other.functions)
&& Arrays.equals(variables, other.variables)
&& converter.equals(other.converter);
}
return false;
}
@Override
public int hashCode() {
return Arrays.hashCode(functions) ^ Arrays.hashCode(variables) ^ converter.hashCode();
}
private void writeObject(ObjectOutputStream out) throws IOException, ClassNotFoundException {
out.defaultWriteObject();
MethodWrapper[] wrappers = new MethodWrapper[functions.length];
for (int i = 0; i < wrappers.length; i++) {
wrappers[i] = new MethodWrapper(functions[i]);
}
out.writeObject(wrappers);
}
private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
in.defaultReadObject();
MethodWrapper[] wrappers = (MethodWrapper[])in.readObject();
if (wrappers.length == 0) {
functions = NO_FUNCTIONS;
} else {
functions = new Method[wrappers.length];
for (int i = 0; i < functions.length; i++) {
functions[i] = wrappers[i].method;
}
}
}
}