1、简介

        Flume 自带 Source 有 Avro、Thrift、Netcat、Taildir、Kafka、Http等，有些场合比如我们指定访问接口获取数据当做 Flume 的 Source，像这种定制化的 Source 需要我们自己实现，下面我将介绍如何自定义实现 Source。

2、自定义实现 Flume 的 Source 

        使用自定义 Source ，访问自身的web 服务，并且发送至 logger 的 Sink。

2.1、引入依赖

<dependencies>
	<dependency>
		<groupId>org.apache.flume</groupId>
		<artifactId>flume-ng-core</artifactId>
		<version>1.11.0</version>
	</dependency>
</dependencies>

 <build>
	<plugins>

	   <plugin>
		   <groupId>org.springframework.boot</groupId>
		   <artifactId>spring-boot-maven-plugin</artifactId>
		   <version>3.2.1</version>
		   <configuration>
			   <skip>true</skip>
		   </configuration>
	   </plugin>
	</plugins>
</build>

2.2、自定义Source

import org.apache.flume.Context;
import org.apache.flume.Event;
import org.apache.flume.EventDeliveryException;
import org.apache.flume.PollableSource;
import org.apache.flume.conf.Configurable;
import org.apache.flume.event.EventBuilder;
import org.apache.flume.source.AbstractSource;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;

public class MySource extends AbstractSource implements Configurable, PollableSource {
     private String path;

     private final static Logger log = LoggerFactory.getLogger(MySource.class);
     
    @Override
    public Status process() throws EventDeliveryException {
        Status status = null;
        try{
            URL url = new URL(this.path);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setRequestMethod("GET");
            connection.connect();

            InputStream is = connection.getInputStream();
            BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(is, "utf-8"));
            StringBuffer stringBuffer = new StringBuffer();

            String line = null;
            while ((line = bufferedReader.readLine()) != null){
                stringBuffer.append(line);
                stringBuffer.append("\t");
            }
            log.info("test =======================: {}" , stringBuffer.toString());
            Event event = EventBuilder.withBody(stringBuffer.toString().getBytes());
            getChannelProcessor().processEvent(event);
            status = Status.READY;
            // 2s调用一次
            Thread.sleep(2000);
        }catch (Exception ex){
            log.info("出错了！, {}", ex.getMessage());
            status = Status.BACKOFF;
        }
        return status;
    }
    @Override
    public long getBackOffSleepIncrement() {
        return 0;
    }
    @Override
    public long getMaxBackOffSleepInterval() {
        return 0;
    }
    @Override
    public void configure(Context context) {
        // 从配置文件中读取
        String path = context.getString("path", "http://baidu.com");
        log.info("path ==========================: {}", path);
        this.path = path;
    }
}

2.3、将自定义Source 打包放到 flume 的 lib目录下

2.4、flume 的配置文件编写 

        vim flume-self-source.conf

a1.sources = r1
a1.channels = c1
a1.sinks=k1
# source
a1.sources.r1.type = com.weilong.flumeselfdefinition.MySource # 自定义 Source 的全限定类名
a1.sources.r1.path = http://192.168.30.33:8088/hello # 自定义参数
# channel
a1.channels.c1.type = memory
a1.channels.c1.capacity = 1000
a1.channels.c1.transactionCapacity = 100
# Sink
a1.sinks.k1.type = logger
# bind
a1.sources.r1.channels = c1
a1.sinks.k1.channel = c1

2.5、测试

2.5.1、启动web服务

2.5.2、启动flume

bin/flume-ng agent -c conf/ -n a1 -f testconf/flume-self-source.conf -Dflume.root.logger=INFO,console

2.5.3、结果 

 

3、总结

        本文详细介绍 Flume 如何实现自定义 Source，帮助大家进一步了解Flume的使用。

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