/**
* Copyright 2004 The Apache Software Foundation
*
* 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.apache.lucene.gdata.storage.lucenestorage;
import java.io.IOException;
import java.io.Serializable;
import java.io.StringWriter;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.gdata.data.ServerBaseEntry;
import org.apache.lucene.gdata.server.registry.ProvidedService;
import org.apache.lucene.gdata.server.registry.ProvidedServiceConfig;
import org.apache.lucene.gdata.storage.lucenestorage.StorageBuffer.BufferableEntry;
import com.google.gdata.data.BaseEntry;
import com.google.gdata.util.common.xml.XmlWriter;
/**
* This immutable class wrapps <tt>ServerBaseEntry</tt> for an internal
* Storage representation of an entry. This class also acts as a Documentfactory
* for lucene documents to be stored inside the index.
*
* @author Simon Willnauer
*
*/
public class StorageEntryWrapper implements Comparable<StorageEntryWrapper>, Serializable,
StorageWrapper {
private static final long serialVersionUID = -4619985652059888526L;
/*
* client api uses UTF-8 to encode server requests and entries
*/
private static final String INTERNAL_ENCODING = "UTF-8";
/**
* lucene field name Entry id
*/
public final static String FIELD_ENTRY_ID = "entryId";
/**
* lucene field name feed id
*/
public final static String FIELD_FEED_REFERENCE = "feedReference";
/**
* lucene field name entry content
*/
public final static String FIELD_CONTENT = "content";
/**
* lucene field name creating timestamp
*/
public final static String FIELD_TIMESTAMP = "timestamp";
/**
* lucene field name entry version
*/
public final static String FIELD_VERSION = "entryVersion";
private int version;
private String entryId;
private String feedId;
private String content;
private transient ServerBaseEntry entry;
private Long timestamp;
private Document document;
private StorageOperation operation;
private transient ProvidedService config;
/**
* Creates a new StorageEntryWrapper.
*
* @param entry -
* the entry to wrap
*
* @param operation -
* the StorageOperation
*
* @throws IOException -
* if the entry content can not be generated
*/
public StorageEntryWrapper(final ServerBaseEntry entry,
StorageOperation operation) throws IOException {
this.entry = entry;
this.operation = operation;
this.entryId = entry.getId();
this.feedId = entry.getFeedId();
this.version = entry.getVersion();
if (operation != StorageOperation.DELETE) {
this.config = entry.getServiceConfig();
this.content = buildContent();
}
this.timestamp = new Long(
this.entry.getUpdated() != null ? this.entry.getUpdated()
.getValue() : System.currentTimeMillis());
}
private String buildContent() throws IOException {
StringWriter writer = new StringWriter();
XmlWriter xmlWriter = new XmlWriter(writer, INTERNAL_ENCODING);
this.entry.generateAtom(xmlWriter, this.config.getExtensionProfile());
return writer.toString();
}
/**
* @see org.apache.lucene.gdata.storage.lucenestorage.StorageWrapper#getLuceneDocument()
*/
public Document getLuceneDocument() {
if(this.operation == StorageOperation.DELETE)
return null;
if (this.document != null)
return this.document;
this.document = new Document();
this.document.add(new Field(FIELD_ENTRY_ID, this.entryId,
Field.Store.YES, Field.Index.UN_TOKENIZED));
this.document.add(new Field(FIELD_FEED_REFERENCE, this.feedId,
Field.Store.YES, Field.Index.UN_TOKENIZED));
this.document.add(new Field(FIELD_CONTENT,this.content,
Field.Store.COMPRESS, Field.Index.NO));
this.document.add(new Field(FIELD_TIMESTAMP, this.timestamp.toString(),
Field.Store.YES, Field.Index.UN_TOKENIZED));
this.document.add(new Field(FIELD_VERSION, Integer.toString(this.version),
Field.Store.YES, Field.Index.UN_TOKENIZED));
return this.document;
}
/**
* @return - the wrapped entry
*/
public BaseEntry getEntry() {
/*
* this wrapps the entry again. BufferableEntry creates a new instance
* for the dynamic element like links.
*/
return new BufferableEntry(this.entry.getEntry());
}
/**
* @return - the entry id
*/
public String getEntryId() {
return this.entryId;
}
/**
* @return - the feed id
*/
public String getFeedId() {
return this.feedId;
}
/**
* Storage operations
*
* @author Simon Willnauer
*
*/
public static enum StorageOperation {
/**
* delete
*/
DELETE,
/**
* update
*/
UPDATE,
/**
* insert
*/
INSERT
}
/**
* @return the specified storage operation
*/
public StorageOperation getOperation() {
return this.operation;
}
/**
* This compare method compares the timestamps of the wrapper instances.
*
* @param arg0 -
* the wrapper to compare
* @par
* @return - 0 if the wrappers timestamp are the same, an integer > 0 if the
* given wrapper is after this wrapper
*
*/
public int compareTo(StorageEntryWrapper arg0) {
return arg0.timestamp.equals(this.timestamp) ? 0
: (arg0.timestamp > this.timestamp ? 1 : -1);
}
/**
* @return - the specified {@link ProvidedServiceConfig}
*/
public ProvidedService getConfigurator() {
return this.config;
}
/**
* @return Returns the timestamp.
*/
public Long getTimestamp() {
return this.timestamp;
}
/**
* @return - the version of the entry
*/
public int getVersion() {
return this.version;
}
}