org.simpleframework.xml.core.ClassCreator Maven / Gradle / Ivy
/*
* ClassCreator.java December 2009
*
* Copyright (C) 2009, Niall Gallagher
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General
* Public License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307 USA
*/
package org.simpleframework.xml.core;
import java.util.List;
/**
* The ClassCreator is responsible for instantiating
* objects using either the default no argument constructor or one
* that takes deserialized values as parameters. This also exposes
* the parameters and constructors used to instantiate the object.
*
* @author Niall Gallagher
*/
class ClassCreator implements Creator {
/**
* This contains a list of all the builders for the class.
*/
private final List list;
/**
* This represents the default no argument constructor used.
*/
private final Builder primary;
/**
* This is used to acquire a parameter by the parameter name.
*/
private final Index index;
/**
* This is the type this builder creates instances of.
*/
private final Class type;
/**
* Constructor for the ClassCreator object. This is
* used to create an object that contains all information that
* relates to the construction of an instance.
*
* @param list this contains the list of all constructors
* @param index this contains all parameters for each constructor
* @param primary this is the default no argument constructor
*/
public ClassCreator(List list, Index index, Builder primary) {
this.type = index.getType();
this.primary = primary;
this.index = index;
this.list = list;
}
/**
* This is used to determine if this Creator has a
* default constructor. If the class does contain a no argument
* constructor then this will return true.
*
* @return true if the class has a default constructor
*/
public boolean isDefault() {
return primary != null;
}
/**
* This is used to instantiate the object using the default no
* argument constructor. If for some reason the object can not be
* instantiated then this will throw an exception with the reason.
*
* @return this returns the object that has been instantiated
*/
public Object getInstance() throws Exception {
return primary.getInstance();
}
/**
* This is used to instantiate the object using a constructor that
* takes deserialized objects as arguments. The object that have
* been deserialized can be taken from the Criteria
* object which contains the deserialized values.
*
* @param criteria this contains the criteria to be used
*
* @return this returns the object that has been instantiated
*/
public Object getInstance(Criteria criteria) throws Exception {
Builder builder = getBuilder(criteria);
if(builder == null) {
throw new PersistenceException("Constructor not matched for %s", type);
}
return builder.getInstance(criteria);
}
/**
* This is used to acquire a Builder which is used
* to instantiate the object. If there is no match for the builder
* then the default constructor is provided.
*
* @param criteria this contains the criteria to be used
*
* @return this returns the builder that has been matched
*/
private Builder getBuilder(Criteria criteria) throws Exception {
Builder result = primary;
int max = 0;
for(Builder builder : list) {
int score = builder.score(criteria);
if(score > max) {
result = builder;
max = score;
}
}
return result;
}
/**
* This is used to acquire the named Parameter from
* the creator. A parameter is taken from the constructor which
* contains annotations for each object that is required. These
* parameters must have a matching field or method.
*
* @param name this is the name of the parameter to be acquired
*
* @return this returns the named parameter for the creator
*/
public Parameter getParameter(String name) {
return index.get(name);
}
/**
* This is used to acquire all parameters annotated for the class
* schema. Providing all parameters ensures that they can be
* validated against the annotated methods and fields to ensure
* that each parameter is valid and has a corrosponding match.
*
* @return this returns the parameters declared in the schema
*/
public List getParameters() {
return index.getParameters();
}
/**
* This is used to acquire all of the Builder objects
* used to create an instance of the object. Each represents a
* constructor and contains the parameters to the constructor.
* This is primarily used to validate each constructor against the
* fields and methods annotated to ensure they are compatible.
*
* @return this returns a list of builders for the creator
*/
public List getBuilders() {
return list;
}
}