appender/socket/src/main/java/org/apache/karaf/decanter/appender/socket/SocketAppender.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF 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 org.apache.karaf.decanter.appender.socket;

import org.apache.karaf.decanter.api.marshaller.Marshaller;
import org.osgi.service.component.ComponentContext;
import org.osgi.service.component.annotations.*;
import org.osgi.service.event.Event;
import org.osgi.service.event.EventConstants;
import org.osgi.service.event.EventHandler;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.PrintWriter;
import java.net.Socket;
import java.util.Dictionary;

@Component(
    name = "org.apache.karaf.decanter.appender.socket",
    immediate = true,
    configurationPolicy = ConfigurationPolicy.REQUIRE,
    property = EventConstants.EVENT_TOPIC + "=decanter/collect/*"
)
public class SocketAppender implements EventHandler {

    private final static Logger LOGGER = LoggerFactory.getLogger(SocketAppender.class);

    private String host;
    private int port;

    private Marshaller marshaller;

    @Activate
    public void activate(ComponentContext componentContext) throws Exception {
        Dictionary<String, Object> config = componentContext.getProperties();
        host = getValue(config, "host", "localhost");
        String portSt = getValue(config, "port", "34343");
        port = Integer.parseInt(portSt);
    }

    @Override
    public void handleEvent(Event event) {
        Socket socket = null;
        PrintWriter writer = null;
        try {
            socket = new Socket(host, port);
            String data = marshaller.marshal(event);
            writer = new PrintWriter(socket.getOutputStream(), true);
            writer.println(data);
        } catch (Exception e) {
            LOGGER.warn("Error sending data on the socket", e);
        } finally {
            if (writer != null) {
                writer.flush();
                writer.close();
            }
            if (socket != null) {
                try {
                    socket.close();
                } catch (Exception e) {
                    // nothing to do
                }
            }
        }
    }

    private String getValue(Dictionary<String, Object> config, String key, String defaultValue) {
        String value = (String)config.get(key);
        return (value != null) ? value :  defaultValue;
    }

    @Reference
    public void setMarshaller(Marshaller marshaller) {
        this.marshaller = marshaller;
    }

}