/* The contents of this file are subject to the license and copyright terms
* detailed in the license directory at the root of the source tree (also
* available online at http://fedora-commons.org/license/).
*/
package org.fcrepo.server.journal.xmlhelpers;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.events.XMLEvent;
import org.fcrepo.server.MultiValueMap;
import org.fcrepo.server.journal.JournalException;
import org.fcrepo.server.journal.entry.JournalEntryContext;
import org.fcrepo.server.journal.helpers.JournalHelper;
import org.fcrepo.server.journal.helpers.PasswordCipher;
/**
* Reads a Context tag from the journal file, and assembles a
* JournalEntryContext from it.
*
* @author Jim Blake
*/
public class ContextXmlReader
extends AbstractXmlReader {
private String passwordType;
/**
* Read the context tax and populate a JournalEntryContext object.
*/
public JournalEntryContext readContext(XMLEventReader reader)
throws JournalException, XMLStreamException {
JournalEntryContext context = new JournalEntryContext();
XMLEvent event = reader.nextTag();
if (!isStartTagEvent(event, QNAME_TAG_CONTEXT)) {
throw getNotStartTagException(QNAME_TAG_CONTEXT, event);
}
context.setPassword(readContextPassword(reader));
context.setNoOp(readContextNoOp(reader));
context.setNow(readContextNow(reader));
context
.setEnvironmentAttributes(readMultiMap(reader,
CONTEXT_MAPNAME_ENVIRONMENT));
context.setSubjectAttributes(readMultiMap(reader,
CONTEXT_MAPNAME_SUBJECT));
context
.setActionAttributes(readMultiMap(reader,
CONTEXT_MAPNAME_ACTION));
context.setResourceAttributes(readMultiMap(reader,
CONTEXT_MAPNAME_RESOURCE));
context.setRecoveryAttributes(readMultiMap(reader,
CONTEXT_MAPNAME_RECOVERY));
event = reader.nextTag();
if (!isEndTagEvent(event, QNAME_TAG_CONTEXT)) {
throw getNotEndTagException(QNAME_TAG_CONTEXT, event);
}
decipherPassword(context);
return context;
}
/**
* Read the context password from XML. Note: While doing this, fetch the
* password type, and store it to use when deciphering the password. Not the
* cleanest structure, perhaps, but it will serve for now.
*/
private String readContextPassword(XMLEventReader reader)
throws JournalException, XMLStreamException {
XMLEvent startTag = readStartTag(reader, QNAME_TAG_PASSWORD);
passwordType =
getOptionalAttributeValue(startTag.asStartElement(),
QNAME_ATTR_PASSWORD_TYPE);
return readCharactersUntilEndTag(reader, QNAME_TAG_PASSWORD);
}
/**
* Read the context no-op flag from XML.
*/
private boolean readContextNoOp(XMLEventReader reader)
throws XMLStreamException, JournalException {
readStartTag(reader, QNAME_TAG_NOOP);
String value = readCharactersUntilEndTag(reader, QNAME_TAG_NOOP);
return Boolean.valueOf(value).booleanValue();
}
/**
* Read the context date from XML.
*/
private Date readContextNow(XMLEventReader reader)
throws XMLStreamException, JournalException {
readStartTag(reader, QNAME_TAG_NOW);
String value = readCharactersUntilEndTag(reader, QNAME_TAG_NOW);
return JournalHelper.parseDate(value);
}
/**
* Read a multi-map, with its nested tags.
*/
private MultiValueMap readMultiMap(XMLEventReader reader, String mapName)
throws JournalException, XMLStreamException {
MultiValueMap map = new MultiValueMap();
// must start with a multi-map tag
XMLEvent event = reader.nextTag();
if (!isStartTagEvent(event, QNAME_TAG_MULTI_VALUE_MAP)) {
throw getNotStartTagException(QNAME_TAG_MULTI_VALUE_MAP, event);
}
// the map name must match the expected name
String value =
getRequiredAttributeValue(event.asStartElement(),
QNAME_ATTR_NAME);
if (!mapName.equals(value)) {
throw new JournalException("Expecting a '" + mapName
+ "' multi-map, but found a '" + value
+ "' multi-map instead");
}
// populate the map
readMultiMapKeys(reader, map);
return map;
}
/**
* Read through the keys of the multi-map, adding to the map as we go.
*/
private void readMultiMapKeys(XMLEventReader reader, MultiValueMap map)
throws XMLStreamException, JournalException {
while (true) {
XMLEvent event2 = reader.nextTag();
if (isStartTagEvent(event2, QNAME_TAG_MULTI_VALUE_MAP_KEY)) {
// if we find a key tag, get the name
String key =
getRequiredAttributeValue(event2.asStartElement(),
QNAME_ATTR_NAME);
// read as many values as we find.
String[] values = readMultiMapValuesForKey(reader);
// store in the map
storeInMultiMap(map, key, values);
} else if (isEndTagEvent(event2, QNAME_TAG_MULTI_VALUE_MAP)) {
break;
} else {
throw getNotNextMemberOrEndOfGroupException(QNAME_TAG_MULTI_VALUE_MAP,
QNAME_TAG_MULTI_VALUE_MAP_KEY,
event2);
}
}
}
/**
* Read the list of values for one key of the multi-map.
*/
private String[] readMultiMapValuesForKey(XMLEventReader reader)
throws XMLStreamException, JournalException {
List<String> values = new ArrayList<String>();
while (true) {
XMLEvent event = reader.nextTag();
if (isStartTagEvent(event, QNAME_TAG_MULTI_VALUE_MAP_VALUE)) {
values
.add(readCharactersUntilEndTag(reader,
QNAME_TAG_MULTI_VALUE_MAP_VALUE));
} else if (isEndTagEvent(event, QNAME_TAG_MULTI_VALUE_MAP_KEY)) {
return values.toArray(new String[values.size()]);
} else {
throw getNotNextMemberOrEndOfGroupException(QNAME_TAG_MULTI_VALUE_MAP_KEY,
QNAME_TAG_MULTI_VALUE_MAP_VALUE,
event);
}
}
}
/**
* This method is just to guard against the totally bogus Exception
* declaration in MultiValueMap.set()
*/
private void storeInMultiMap(MultiValueMap map, String key, String[] values)
throws JournalException {
try {
map.set(key, values);
} catch (Exception e) {
// totally bogus Exception here.
throw new JournalException(e);
}
}
/**
* The password as read was not correct. It needs to be deciphered.
*/
private void decipherPassword(JournalEntryContext context) {
String key = JournalHelper.formatDate(context.now());
String passwordCipher = context.getPassword();
String clearPassword =
PasswordCipher.decipher(key, passwordCipher, passwordType);
context.setPassword(clearPassword);
}
}