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Protempa Framework is the core of Protempa.
/*
* #%L
* Protempa Framework
* %%
* Copyright (C) 2012 - 2013 Emory University
* %%
* 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.
* #L%
*/
package org.protempa.xml;
import com.thoughtworks.xstream.converters.ConversionException;
import com.thoughtworks.xstream.converters.Converter;
import com.thoughtworks.xstream.converters.MarshallingContext;
import com.thoughtworks.xstream.converters.UnmarshallingContext;
import com.thoughtworks.xstream.io.HierarchicalStreamReader;
import com.thoughtworks.xstream.io.HierarchicalStreamWriter;
import com.thoughtworks.xstream.mapper.Mapper;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.Properties;
import java.util.Set;
import org.protempa.KnowledgeSource;
import org.protempa.proposition.value.Unit;
import org.protempa.proposition.value.Value;
/**
* Base class for implementing XStream converters.
*
* @author mgrand
*/
abstract class AbstractConverter implements Converter {
private final KnowledgeSource knowledgeSource;
AbstractConverter(KnowledgeSource knowledgeSource) {
this.knowledgeSource = knowledgeSource;
}
KnowledgeSource getKnowledgeSource() {
return knowledgeSource;
}
/**
* Throw an exception if the current XML element does not have the expected
* name.
*
* @param reader The object used to inquire about the current XML element.
* @param elementName The expected element name
* @throws ConversionException if the current element does not have the expected name.
*/
protected void expect(HierarchicalStreamReader reader, String elementName) {
if (!elementName.equals(reader.getNodeName())) {
String msg = "Expected a " + elementName + " element but found " + reader.getNodeName();
throw new ConversionException(msg);
}
}
/**
* Throw an exception if the current XML element does not have one of the
* expected names.
*
* @param reader The object used to inquire about the current XML element.
* @param elementNames The expected element names.
* @return the tag of the current element.
* @throws ConversionException if the current element does not have the expected name.
*/
protected String expect(HierarchicalStreamReader reader, Set elementNames) {
String tag = reader.getNodeName();
if (!elementNames.contains(tag)) {
String msg = "Expected an element whose tag is one of " + elementNames + " but found " + reader.getNodeName();
throw new ConversionException(msg);
}
return tag;
}
/**
* Throw an exception if the current XML element has any unprocessed
* children.
*
* @param reader The object used to inquire about the current XML element.
* @throws ConversionException if the current element has any unprocessed children.
*/
protected void expectNoMore(HierarchicalStreamReader reader) {
if (reader.hasMoreChildren()) {
String msg = "Element contains unexpected child elements";
throw new ConversionException(msg);
}
}
/**
* Throw an exception if the current XML element has no unprocessed
* children.
*
* @param reader The object used to inquire about the current XML element.
* @throws ConversionException if the current element does not have the expected name.
*/
protected void expectChildren(HierarchicalStreamReader reader) {
if (!reader.hasMoreChildren()) {
String msg = "Element contains no child elements but is required to contain at least one.";
throw new ConversionException(msg);
}
}
/**
* Get the value of the named attribute from the given reader. If the named
* attribute is not specified, then throw a ConversionException.
*
* @param reader The object used to inquire about the current XML element.
* @param attributeName The name of the attribute to get a value for.
* @return The value of the attribute.
*/
protected String requiredAttributeValue(HierarchicalStreamReader reader, String attributeName) {
String value = reader.getAttribute(attributeName);
if (value == null) {
missingAttribute(attributeName);
}
return value;
}
private void missingAttribute(String attributeName) {
String msg = "The current element does not specify a value for an attribute named \"" + attributeName + "\"";
throw new ConversionException(msg);
}
/**
* Get the int value of the named attribute from the given reader. If the
* named attribute is not specified, then throw a ConversionException.
*
* @param reader The object used to inquire about the current XML element.
* @param attributeName The name of the attribute to get a value for.
* @return The value of the attribute.
* @throws ConversionException if the specified value of the attribute can not be parsed as
* an int.
*/
protected int intAttributeValue(HierarchicalStreamReader reader, String attributeName) {
String valueString = requiredAttributeValue(reader, attributeName);
int value;
try {
value = Integer.parseInt(valueString);
} catch (Exception e) {
String msg = "Unable to parse value of attribute n: \"" + valueString + "\"";
throw new ConversionException(msg, e);
}
return value;
}
/**
* Get the int value of the named attribute from the given reader. If the
* named attribute is not specified, then return the given default value.
*
* @param reader The object used to inquire about the current XML element.
* @param attributeName The name of the attribute to get a value for.
* @param defaultValue The default value to use if the named attribute is not
* specified.
* @return The value of the attribute.
* @throws ConversionException if the specified value of the attribute can not be parsed as
* an int.
*/
protected int intAttributeValue(HierarchicalStreamReader reader, String attributeName, int defaultValue) {
String valueString = reader.getAttribute(attributeName);
int value;
if (valueString == null) {
value = 1;
} else {
try {
value = Integer.parseInt(valueString);
} catch (Exception e) {
String msg = "Unable to parse value of attribute n: \"" + valueString + "\"";
throw new ConversionException(msg, e);
}
}
return value;
}
/**
* Get the value of the named attribute from the given reader as an Integer
* object. If the named attribute is not specified, then return null.
*
* @param reader The object used to inquire about the current XML element.
* @param attributeName The name of the attribute to get a value for.
* @return The value of the attribute.
* @throws ConversionException if the specified value of the attribute can not be parsed as
* an int.
*/
protected Integer integerAttributeValue(HierarchicalStreamReader reader, String attributeName) {
String valueString = reader.getAttribute(attributeName);
Integer value;
if (valueString == null) {
value = null;
} else {
try {
value = Integer.valueOf(valueString);
} catch (Exception e) {
String msg = "Unable to parse value of attribute n: \"" + valueString + "\"";
throw new ConversionException(msg, e);
}
}
return value;
}
private static final UnitValueConverter unitConverter = new UnitValueConverter();
/**
* Get the value of the named attribute from the given reader as a {@link Unit}
* object. If the named attribute is not specified, then return null.
*
* @param reader The object used to inquire about the current XML element.
* @param attributeName The name of the attribute to get a value for.
* @return The value of the attribute.
* @throws ConversionException if the specified value of the attribute can not be recognized
* as a Unit.
*/
protected Unit unitAttributeValue(HierarchicalStreamReader reader, String attributeName) {
String valueString = reader.getAttribute(attributeName);
Unit value;
if (valueString == null) {
value = null;
} else {
try {
value = (Unit) unitConverter.fromString(valueString);
} catch (Exception e) {
String msg = "Unable to parse value of attribute n: \"" + valueString + "\"";
throw new ConversionException(msg, e);
}
}
return value;
}
/**
* Write an entire Value XML element, including the element tag. This is
* different than XStream's marshal that writes the attributes, child
* elements and contents, but does not write the tag.
*
* @param writer The {@link} HierarchicalStreamWriter} object that XStream
* passed into a marshal method.
* @param context The {@link MarshallingContext} object that XStream passed into
* a marshal method.
* @param value The {@link Value} object to be written as XML.
*/
protected void valueToXML(HierarchicalStreamWriter writer, MarshallingContext context, Value value) {
Mapper mapper = XMLConfiguration.getTableQueryResultsHandlerXStream(this.knowledgeSource).getMapper();
String valueElementTag = mapper.serializedClass(value.getClass());
writer.startNode(valueElementTag);
context.convertAnother(value);
writer.endNode();
}
/**
* Read an entire Value XML element, including the element tag. This is
* different than XStream's unmarshal that reads the attributes, child
* elements and contents, but does not read the tag.
*
* @param reader
* @param context
* @return
*/
protected Value valueFromXML(HierarchicalStreamReader reader, UnmarshallingContext context) {
Value value;
reader.moveDown();
Mapper mapper = XMLConfiguration.getTableQueryResultsHandlerXStream(this.knowledgeSource).getMapper();
@SuppressWarnings("unchecked")
Class type = (Class) mapper.realClass(reader.getNodeName());
value = (Value) context.convertAnother(null, type);
reader.moveUp();
return value;
}
// Cached properties for URLS
private static Properties urlProperties = null;
private static URL propertiesUrl;
/**
* Return the URL of the schema to use for validating XML.
*
* @param propertyName The property name whose value is the URL of interest.
*/
protected static URL getUrl(String propertyName) {
if (urlProperties == null) {
propertiesUrl = QueryConverter.class.getResource("urls.properties");
try {
InputStream inStream = propertiesUrl.openStream();
Properties props = new Properties();
props.load(inStream);
urlProperties = props;
} catch (Exception e) {
String msg = "Error occurred while trying to read properties from " + propertiesUrl.toExternalForm();
throw new RuntimeException(msg, e);
}
}
String urlString = urlProperties.getProperty(propertyName);
if (urlString == null) {
String msg = "Configuration error: " + propertiesUrl.toExternalForm() + " does not specify a value for the property " + propertyName;
throw new RuntimeException(msg);
}
try {
URL querySchemaUrl = new URL(urlString);
return querySchemaUrl;
} catch (IOException e) {
String msg = "Error parsing URL that was specified as the value of the " + propertyName + " property in " + propertiesUrl.toExternalForm();
msg += "\nThe problem URL is " + urlString;
throw new RuntimeException(msg, e);
}
}
protected static String nullAsEmptyString(String str) {
if (str == null) {
return "";
} else {
return str;
}
}
}
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