com.wandrell.pattern.outputter.xml.XMLOutputter Maven / Gradle / Ivy
/**
* The MIT License (MIT)
*
* Copyright (c) 2014 the original author or authors.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
package com.wandrell.pattern.outputter.xml;
import static com.google.common.base.Preconditions.checkNotNull;
import java.io.OutputStream;
import java.io.Writer;
import org.jdom2.Attribute;
import org.jdom2.DocType;
import org.jdom2.Document;
import org.jdom2.Element;
import org.jdom2.Namespace;
import org.jdom2.output.Format;
import com.wandrell.pattern.conf.XMLValidationType;
import com.wandrell.pattern.outputter.Outputter;
/**
* Implementation of {@link Outputter} for XML files. Behind the scenes this is
* based on the JDOM 2 API.
*
* The data is received as a JDOM 2 {@link org.jdom2.Document Document}, along
* the output object to be used.
*
* It is also possible to include XML validation data, which will be added to
* the {@code Document} before sending it. This should be set using the
* {@link #setValidation(Document) setValidation} method before outputting the
* data.
*
* Note that the validation file path won't be checked in any way, just stored
* on the resulting file as received.
*
* @author Bernardo Martínez Garrido
* @see Document
*/
public final class XMLOutputter implements Outputter {
/**
* The name of the element which will register the validation file being
* used.
*
* This will be used only if DTD validation is set.
*/
private static final String ELEMENT_VALID = "validator";
/**
* Prefix for the validation namespace.
*
* This will be used only if XSD validation is set.
*/
private static final String NAMESPACE_PREFIX = "xsi";
/**
* URI for the validation namespace.
*
* This will be used only if XSD validation is set.
*/
private static final String NAMESPACE_URI = "http://www.w3.org/2001/XMLSchema-instance";
/**
* Attribute indicating the validation file location.
*
* This will be used only if XSD validation is set.
*/
private static final String XSD_ATTRIBUTE = "noNamespaceSchemaLocation";
/**
* Path to the validation file.
*
* It should be noted that this file won't be read or validated in any way.
*
* The path will be stored along the rest of the validation data on the
* resulting file, but only if any kind of validation has been set.
*/
private String valFilePath;
/**
* Type of validation being used.
*
* If the validation is set to 'NONE' no validation will be applied.
*/
private XMLValidationType validationType;
/**
* Constructs an {@code XMLOutputter} with no validation.
*/
public XMLOutputter() {
this(XMLValidationType.NONE, "");
}
/**
* Constructs an {@code XMLOutputter} with the specified validation
* information.
*
* Note that the received path will just be added to the resulting file as
* received, and it won't be read of checked in any way.
*
* @param validation
* the validation type
* @param validationPath
* path to the validation file
*/
public XMLOutputter(final XMLValidationType validation,
final String validationPath) {
super();
checkNotNull(validation, "Received a null pointer as validation type");
checkNotNull(validationPath,
"Received a null pointer as validation path");
validationType = validation;
valFilePath = validationPath;
}
/**
* Sends a {@code Document} through an {@code OutputStream}.
*
* The {@code Document} will be transformed into an XML text file.
*
* @param value
* {@code Document} to send
* @param stream
* {@code OutputStream} to receive the resulting XML text
* @throws Exception
* when there's any problem on the outputting process
*/
@Override
public final void output(final Document value, final OutputStream stream)
throws Exception {
checkNotNull(value, "Received a null pointer as value");
checkNotNull(stream, "Received a null pointer as output stream");
final Document doc;
doc = value.clone();
setValidation(doc);
new org.jdom2.output.XMLOutputter(Format.getPrettyFormat()).output(doc,
stream);
}
/**
* Sends a {@code Document} through a {@code Writer}.
*
* The {@code Document} will be transformed into an XML text file.
*
* @param value
* {@code Document} to send
* @param writer
* {@code Writer} to receive the resulting XML text
* @throws Exception
* when there's any problem on the writing process
*/
@Override
public final void output(final Document value, final Writer writer)
throws Exception {
checkNotNull(value, "Received a null pointer as value");
checkNotNull(writer, "Received a null pointer as writer");
final Document doc;
doc = value.clone();
setValidation(doc);
new org.jdom2.output.XMLOutputter(Format.getPrettyFormat()).output(doc,
writer);
}
/**
* Sets the validation data to be stored on the resulting XML structure.
*
* Note that the path won't be checked in any way, it will just be stored as
* received on the {@code Document} validation information before sending
* it.
*
* @param validation
* the validation type
* @param path
* path to the validation file
*/
public final void setValidation(final XMLValidationType validation,
final String path) {
checkNotNull(validation, "Received a null pointer as validation type");
checkNotNull(path, "Received a null pointer as validation path");
validationType = validation;
valFilePath = path;
}
/**
* Returns the name of the element which will register the validation file.
*
* This is used for DTD validation.
*
* @return the DTD validation file element name
*/
private final String getDTDValidatorName() {
return ELEMENT_VALID;
}
/**
* Returns the path to the validation file.
*
* This file won't be read or checked in any way, it will just be stored in
* the {@code Document} as part of the validation info.
*
* @return the path to the validation file.
*/
private final String getValidationPath() {
return valFilePath;
}
/**
* Returns the type of validation being used.
*
* @return the type of validation being used
*/
private final XMLValidationType getValidationType() {
return validationType;
}
/**
* Returns the attribute which indicates the validation file location.
*
* This is used for XSD validation.
*
* @return the XSD validation file attribute
*/
private final String getXSDAttribute() {
return XSD_ATTRIBUTE;
}
/**
* Returns the validation namespace.
*
* This is used for XSD validation.
*
* @return the validation file namespace
*/
private final Namespace getXSDNamespace() {
return Namespace.getNamespace(NAMESPACE_PREFIX, NAMESPACE_URI);
}
/**
* Sets the validation data into the specified {@code Document}.
*
* How the data will be stores depends on the type of validation being used,
* and in case of applying no validation the {@code Document} won't be
* touched.
*
* @param doc
* the {@code Document} into which to set the validation data
*/
private final void setValidation(final Document doc) {
final Namespace namespc; // Namespace for the XSD file
final Element root; // Document's root
switch (getValidationType()) {
case XSD:
root = doc.getRootElement();
namespc = getXSDNamespace();
root.addNamespaceDeclaration(namespc);
root.setAttribute(new Attribute(getXSDAttribute(),
getValidationPath(), namespc));
break;
case DTD:
doc.setDocType(new DocType(getDTDValidatorName(),
getValidationPath()));
break;
default:
}
}
}