/**
* Licensed to Cloudera, Inc. under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. Cloudera, Inc. licenses this file
* to you 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 helloworld;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import com.cloudera.flume.conf.Context;
import com.cloudera.flume.conf.SinkFactory.SinkDecoBuilder;
import com.cloudera.flume.core.Event;
import com.cloudera.flume.core.EventImpl;
import com.cloudera.flume.core.EventSink;
import com.cloudera.flume.core.EventSinkDecorator;
import com.cloudera.util.Pair;
import com.google.common.base.Preconditions;
/**
* Simple Decorator that prepends "Hello World!" to every event body.
*/
public class HelloWorldDecorator<S extends EventSink> extends EventSinkDecorator<S> {
public HelloWorldDecorator(S s) {
super(s);
}
@Override
public void append(Event e) throws IOException {
String helloWorldBody = "Hello World! -- " + new String(e.getBody());
// make a copy of the event, but with the new body string.
EventImpl e2 = new EventImpl(helloWorldBody.getBytes(),
e.getTimestamp(), e.getPriority(), e.getNanos(), e.getHost(),
e.getAttrs());
super.append(e2);
}
public static SinkDecoBuilder builder() {
return new SinkDecoBuilder() {
// construct a new parameterized decorator
@Override
public EventSinkDecorator<EventSink> build(Context context,
String... argv) {
Preconditions.checkArgument(argv.length == 0,
"usage: helloWorldDecorator");
return new HelloWorldDecorator<EventSink>(null);
}
};
}
/**
* This is a special function used by the SourceFactory to pull in this class
* as a plugin decorator.
*/
public static List<Pair<String, SinkDecoBuilder>> getDecoratorBuilders() {
List<Pair<String, SinkDecoBuilder>> builders =
new ArrayList<Pair<String, SinkDecoBuilder>>();
builders.add(new Pair<String, SinkDecoBuilder>("helloWorldDecorator",
builder()));
return builders;
}
}