org.simpleframework.xml.core.PrimitiveValue Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of simple-xml Show documentation
Show all versions of simple-xml Show documentation
Simple is a high performance XML serialization and configuration framework for Java
The newest version!
/*
* PrimitiveValue.java July 2007
*
* Copyright (C) 2007, Niall Gallagher
*
* 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.simpleframework.xml.core;
import org.simpleframework.xml.strategy.Type;
import org.simpleframework.xml.stream.InputNode;
import org.simpleframework.xml.stream.OutputNode;
import org.simpleframework.xml.stream.Style;
/**
* The PrimitiveValue is used to serialize a primitive
* value to and from a node. If a value name is provided in the
* annotation then this will serialize and deserialize that value
* with the given name, if the value is primitive and no name is
* specified then the value is written inline, that is without any
* enclosing XML element.
*
*
* <entry key="one">example one</entry>
* <entry key="two">example two</entry>
* <entry key="three">example three</entry>
*
*
* Allowing the value to be written as either an XML element or an
* inline text value enables a more flexible means for representing
* the value. The only condition for having an inline value is that
* the key is specified as an attribute in the annotation.
*
* @author Niall Gallagher
*
* @see org.simpleframework.xml.core.CompositeMap
*/
class PrimitiveValue implements Converter {
/**
* The primitive factory used to resolve the primitive to a string.
*/
private final PrimitiveFactory factory;
/**
* This is the context used to support the serialization process.
*/
private final Context context;
/**
* The primitive converter used to read the value from the node.
*/
private final Primitive root;
/**
* This is the style used to style the XML names for the value.
*/
private final Style style;
/**
* The entry object contains the details on how to write the value.
*/
private final Entry entry;
/**
* Represents the primitive type the value is serialized to and from.
*/
private final Type type;
/**
* Constructor for the PrimitiveValue object. This is
* used to create the value object which converts the map value to
* an instance of the value type. This can also resolve references.
*
* @param context this is the context object used for serialization
* @param entry this is the entry object that describes entries
* @param type this is the type that this converter deals with
*/
public PrimitiveValue(Context context, Entry entry, Type type) {
this.factory = new PrimitiveFactory(context, type);
this.root = new Primitive(context, type);
this.style = context.getStyle();
this.context = context;
this.entry = entry;
this.type = type;
}
/**
* This method is used to read the value value from the node. The
* value read from the node is resolved using the template filter.
* If the value value can not be found according to the annotation
* attributes then an exception is thrown.
*
* @param node this is the node to read the value object from
*
* @return this returns the value deserialized from the node
*/
public Object read(InputNode node) throws Exception {
Class expect = type.getType();
String name = entry.getValue();
if(!entry.isInline()) {
if(name == null) {
name = context.getName(expect);
}
return readElement(node, name);
}
return readAttribute(node, name);
}
/**
* This method is used to read the value value from the node. The
* value read from the node is resolved using the template filter.
* If the value value can not be found according to the annotation
* attributes then an exception is thrown.
*
* @param node this is the node to read the value object from
* @param value this is the value to deserialize in to
*
* @return this returns the value deserialized from the node
*
* @throws Exception if value is not null an exception is thrown
*/
public Object read(InputNode node, Object value) throws Exception {
Class expect = type.getType();
if(value != null) {
throw new PersistenceException("Can not read value of %s for %s", expect, entry);
}
return read(node);
}
/**
* This method is used to read the element value from the node. The
* value read from the node is resolved using the template filter.
* If the value value can not be found according to the annotation
* attributes then null is assumed and returned.
*
* @param node this is the node to read the value object from
* @param key this is the name of the value XML element
*
* @return this returns the value deserialized from the node
*/
private Object readElement(InputNode node, String key) throws Exception {
String name = style.getAttribute(key);
InputNode child = node.getNext(name);
if(child == null) {
return null;
}
return root.read(child);
}
/**
* This method is used to read the text value from the node. The
* value read from the node is resolved using the template filter.
* If the value value can not be found according to the annotation
* attributes then null is assumed and returned.
*
* @param node this is the node to read the value object from
* @param name this is the name of the value XML attribute, if any
*
* @return this returns the value deserialized from the node
*/
private Object readAttribute(InputNode node, String name) throws Exception {
if(name != null) {
name = style.getAttribute(name);
node = node.getAttribute(name);
}
if(node == null) {
return null;
}
return root.read(node);
}
/**
* This method is used to validate the value from the node. The
* value read from the node is resolved using the template filter.
* If the value value can not be found according to the annotation
* attributes then null is assumed and the node is valid.
*
* @param node this is the node to read the value object from
*
* @return this returns true if the primitive key is valid
*/
public boolean validate(InputNode node) throws Exception {
Class expect = type.getType();
String name = entry.getValue();
if(!entry.isInline()) {
if(name == null) {
name = context.getName(expect);
}
return validateElement(node, name);
}
return validateAttribute(node, name);
}
/**
* This method is used to validate the value from the node. The
* value read from the node is resolved using the template filter.
* If the value value can not be found according to the annotation
* attributes then null is assumed and the node is valid.
*
* @param node this is the node to read the value object from
* @param key this is the name of the node to be validated
*
* @return this returns true if the primitive key is valid
*/
private boolean validateElement(InputNode node, String key) throws Exception {
String name = style.getAttribute(key);
InputNode child = node.getNext(name);
if(child == null) {
return true;
}
return root.validate(node);
}
/**
* This method is used to validate the value from the node. The
* value read from the node is resolved using the template filter.
* If the value value can not be found according to the annotation
* attributes then null is assumed and the node is valid.
*
* @param node this is the node to read the value object from
* @param key this is the name of the node to be validated
*
* @return this returns true if the primitive key is valid
*/
private boolean validateAttribute(InputNode node, String key) throws Exception {
if(key != null) {
key = style.getAttribute(key);
node = node.getNext(key);
}
if(node == null) {
return true;
}
return root.validate(node);
}
/**
* This method is used to write the value to the specified node.
* The value written to the node can be an attribute or an element
* depending on the annotation attribute values. This method will
* maintain references for serialized elements.
*
* @param node this is the node that the value is written to
* @param item this is the item that is to be written
*/
public void write(OutputNode node, Object item) throws Exception {
Class expect = type.getType();
String name = entry.getValue();
if(!entry.isInline()) {
if(name == null) {
name = context.getName(expect);
}
writeElement(node, item, name);
} else {
writeAttribute(node, item, name);
}
}
/**
* This method is used to write the value to the specified node.
* The value written to the node can be an attribute or an element
* depending on the annotation attribute values. This method will
* maintain references for serialized elements.
*
* @param node this is the node that the value is written to
* @param item this is the item that is to be written
* @param key this is the name of the element to be created
*/
private void writeElement(OutputNode node, Object item, String key) throws Exception {
String name = style.getAttribute(key);
OutputNode child = node.getChild(name);
if(item != null) {
if(!isOverridden(child, item)) {
root.write(child, item);
}
}
}
/**
* This method is used to write the value to the specified node.
* The value written to the node can be an attribute or an element
* depending on the annotation attribute values. This method will
* maintain references for serialized elements.
*
* @param node this is the node that the value is written to
* @param item this is the item that is to be written
* @param key this is the name of the attribute to be created
*/
private void writeAttribute(OutputNode node, Object item, String key) throws Exception {
if(item != null) {
if(key != null) {
key = style.getAttribute(key);
node = node.setAttribute(key, null);
}
root.write(node, item);
}
}
/**
* This is used to determine whether the specified value has been
* overridden by the strategy. If the item has been overridden
* then no more serialization is require for that value, this is
* effectively telling the serialization process to stop writing.
*
* @param node the node that a potential override is written to
* @param value this is the object instance to be serialized
*
* @return returns true if the strategy overrides the object
*/
private boolean isOverridden(OutputNode node, Object value) throws Exception{
return factory.setOverride(type, value, node);
}
}