Flume六：自定义 Sink

案例

自定义实现类

package com.flume.sinks;

import org.apache.flume.*;
import org.apache.flume.conf.Configurable;
import org.apache.flume.sink.AbstractSink;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Created by HP on 2020/1/19.
 */
public class MySink extends AbstractSink implements Configurable{
    //定义logger对象
    Logger logger;

    //定义两个属性
    private String prefix;
    private String subfix;

    @Override
    public void configure(Context context) {
        //获取logger对象，用于将数据打印到控制台，方便测试查看数据输出的效果
        logger=LoggerFactory.getLogger(MySink.class);

        //读取配置文件，为参数赋值
        prefix=context.getString("prefix","prefix");
        subfix=context.getString("subfix");
    }

    /**
     * 1、定义返回状态
     * 2、获取channel
     * 3、从channel中获取 事务和数据
     * 4、发送数据
     *
     * @return
     * @throws EventDeliveryException
     */
    @Override
    public Status process() throws EventDeliveryException {
        //1、定义返回状态
        Status status=Status.BACKOFF;
        //2、获取当前 Sink 绑定的 Channel
        Channel channel = getChannel();
        //3、获取事务
        Transaction transaction = channel.getTransaction();
        //4、开启事务
        transaction.begin();
        try {
            //5、读取 Channel 中的事件，直到读取到事件结束循环
                //声明事件
            Event event ;
            while (true) {
                event = channel.take();
                if (event != null) {
                    break;
                }
            }
            //6、处理数据：此处就是业务逻辑代码了，将数据写到何方
                //从事件中获取body
            String body = new String(event.getBody());
                //打印事件中的body
            logger.info("["+prefix+" -- "+body+" -- "+subfix+"]");
            //7、提交事务
            transaction.commit();
            //8、修改状态
            status=Status.READY;
        } catch (ChannelException e) {
            //回滚数据
            transaction.rollback();

            status=Status.BACKOFF;
            e.printStackTrace();
        } finally {
            //关闭事务
            transaction.close();
        }
        return status;
    }

}

agent配置文件

#定义
a1.sources = r1
a1.channels = c1
a1.sinks = k1

#source
a1.sources.r1.type = netcat
a1.sources.r1.bind = node2
a1.sources.r1.port = 44444

#channel
a1.channels.c1.type = memory
a1.channels.c1.capacity = 1000
a1.channels.c1.transactionCapacity = 100

#sink
a1.sinks.k1.type = com.flume.sinks.MySink
a1.sinks.k1.prefix = kaishi
a1.sinks.k1.subfix = ceshi

#bind
a1.sources.r1.channels = c1
a1.sinks.k1.channel = c1

启动

flume-ng agent -n a1 -c conf -f /opt/flume_conf/flume_sink.conf -Dflume.root.logger=INFO,console