stream.data.CreateID Maven / Gradle / Ivy
/*
* streams library
*
* Copyright (C) 2011-2012 by Christian Bockermann, Hendrik Blom
*
* streams is a library, API and runtime environment for processing high
* volume data streams. It is composed of three submodules "stream-api",
* "stream-core" and "stream-runtime".
*
* The streams library (and its submodules) is free software: you can
* redistribute it and/or modify it under the terms of the
* GNU Affero General Public License as published by the Free Software
* Foundation, either version 3 of the License, or (at your option) any
* later version.
*
* The stream.ai library (and its submodules) is distributed in the hope
* that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see http://www.gnu.org/licenses/.
*/
package stream.data;
import stream.AbstractProcessor;
import stream.annotations.Description;
import stream.annotations.Parameter;
import stream.service.Service;
/**
*
* This class adds a single ID attribute to all processed items.
*
*
* @author Christian Bockermann <[email protected]>
*
*/
@Description(text = "This processor tags all processed items with integer IDs.", group = "Data Stream.Processing.Annotations")
public class CreateID extends AbstractProcessor implements Service {
Long start = 1L;
Long nextId = 1L;
String key = "@id";
/**
* @see stream.DataProcessor#process(stream.data.Data)
*/
@Override
public Data process(Data data) {
if (key != null) {
synchronized (nextId) {
data.put(key, nextId++);
}
}
return data;
}
/**
* @return the key
*/
public String getKey() {
return key;
}
/**
* @param key
* the key to set
*/
@Parameter(defaultValue = "@id")
public void setKey(String key) {
this.key = key;
}
@Parameter(defaultValue = "0")
public void setStart(Long l) {
start = l;
nextId = start;
}
public Long getStart() {
return start;
}
/**
* @see stream.service.Service#reset()
*/
@Override
public void reset() throws Exception {
nextId = start;
}
}