/*
* Copyright © 2014-2015 Cask Data, Inc.
*
* 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 co.cask.cdap.gateway.apps;
import co.cask.cdap.api.annotation.ProcessInput;
import co.cask.cdap.api.annotation.UseDataSet;
import co.cask.cdap.api.app.AbstractApplication;
import co.cask.cdap.api.common.Bytes;
import co.cask.cdap.api.data.stream.Stream;
import co.cask.cdap.api.dataset.lib.KeyValueTable;
import co.cask.cdap.api.flow.AbstractFlow;
import co.cask.cdap.api.flow.flowlet.AbstractFlowlet;
import co.cask.cdap.api.flow.flowlet.FlowletContext;
import co.cask.cdap.api.flow.flowlet.StreamEvent;
import co.cask.cdap.api.service.BasicService;
import co.cask.cdap.api.service.http.AbstractHttpServiceHandler;
import co.cask.cdap.api.service.http.HttpServiceRequest;
import co.cask.cdap.api.service.http.HttpServiceResponder;
import java.io.IOException;
import java.util.Map;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
/**
* App that filters based on a threshold.
* To test runtimeArgs.
*/
public class HighPassFilterApp extends AbstractApplication {
public static final String NAME = "HighPassFilterApp";
private static final byte[] highPass = Bytes.toBytes("h");
@Override
public void configure() {
setName(NAME);
setDescription("Application for filtering numbers. Test runtimeargs.");
addStream(new Stream("inputvalue"));
createDataset("counter", KeyValueTable.class);
addFlow(new FilterFlow());
addService(new BasicService("Count", new CountHandler()));
}
/**
* Flow to implement highpass filter.
*/
public static class FilterFlow extends AbstractFlow {
@Override
protected void configureFlow() {
setName("FilterFlow");
setDescription("Flow for counting words");
addFlowlet("filter", new Filter());
connectStream("inputvalue", "filter");
}
}
/**
* Flowlet that has filtering logic.
*/
public static class Filter extends AbstractFlowlet {
@UseDataSet("counter")
private KeyValueTable counters;
private long threshold = 0L;
@ProcessInput
public void process(StreamEvent event) {
//highpass filter.
String value = Bytes.toString(event.getBody());
if (Long.parseLong(value) > threshold) {
counters.increment(highPass, 1L);
}
}
@Override
public void initialize(FlowletContext context) throws Exception {
Map<String, String> args = context.getRuntimeArguments();
if (args.containsKey("threshold")) {
this.threshold = Long.parseLong(args.get("threshold"));
}
super.initialize(context);
}
}
/**
* return counts.
*/
public static class CountHandler extends AbstractHttpServiceHandler {
@UseDataSet("counter")
private KeyValueTable counters;
@GET
@Path("result")
public void handle(HttpServiceRequest request, HttpServiceResponder responder) throws IOException {
byte[] result = counters.read(highPass);
if (result == null) {
responder.sendStatus(404);
} else {
responder.sendJson(Bytes.toLong(result));
}
}
}
}