【Flume中间件】（12）自定义拦截器

自定义拦截器

在有些情况下，我们需要对采集来的数据进行分类，那么我们就可以采用multiplexing拦截器的方式，在数据中添加头部的键值，根据键值选择相应的channel。

我们自定义拦截器需要实现官方的Interceptor，实现相应的方法，而且还需要一个静态内部类，用于返回Interceptor类。

而且在实现interceptor方法时，可以进行丢失据，就是有些不符合条件的数据就抛弃掉，可以进行简单的过滤，直接返回null即可。

下面实现的就是服务器1进行监听一个数据，如果该数据中存在“hello”字符串，就将其传入服务器2，否则就将其传入服务器3.

a1.sources = r1
a1.sinks = k1 k2
a1.channels = c1 c2

a1.sources.r1.type = taildir
a1.sources.r1.positionFile = /opt/module/flume/position/position.json
a1.sources.r1.filegroups = f1
a1.sources.r1.filegroups.f1 = /home/hadoop/data3/data6

a1.sources.r1.interceptors=i1
a1.sources.r1.interceptors.i1.type=com.atguigu.Interceptor.MyInterceptor$Builder

a1.sources.r1.selector.type=multiplexing
a1.sources.r1.selector.header=type
a1.sources.r1.selector.mapping.yes=c1
a1.sources.r1.selector.mapping.no=c2

a1.sinks.k1.type = avro
a1.sinks.k1.hostname=hadoop103
a1.sinks.k1.port=4141

a1.sinks.k2.type = avro
a1.sinks.k2.hostname=hadoop104
a1.sinks.k2.port=4141

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

a1.channels.c2.type = memory
a1.channels.c2.capacity = 1000
a1.channels.c2.transactionCapacity = 100

a1.sources.r1.channels = c1 c2
a1.sinks.k1.channel = c1  
a1.sinks.k2.channel = c2

a2.sources = r1
a2.sinks = k1
a2.channels = c1

a2.sources.r1.type = avro
a2.sources.r1.bind=hadoop103
a2.sources.r1.port=4141

a2.sinks.k1.type = logger

a2.channels.c1.type = memory
a2.channels.c1.capacity = 1000
a2.channels.c1.transactionCapacity = 100

a2.sources.r1.channels = c1
a2.sinks.k1.channel = c1

a3.sources = r1
a3.sinks = k1
a3.channels = c1

a3.sources.r1.type = avro
a3.sources.r1.bind=hadoop104
a3.sources.r1.port=4141

a3.sinks.k1.type = logger

a3.channels.c1.type = memory
a3.channels.c1.capacity = 1000
a3.channels.c1.transactionCapacity = 100

a3.sources.r1.channels = c1
a3.sinks.k1.channel = c1

package com.atguigu.Interceptor;

import org.apache.flume.Context;
import org.apache.flume.Event;
import org.apache.flume.interceptor.Interceptor;

import java.util.ArrayList;
import java.util.List;

public class MyInterceptor implements Interceptor {

    ArrayList<Event> list_event;

    @Override
    public void initialize() {
        list_event = new ArrayList<>();
    }

    @Override
    public Event intercept(Event event) {
        # 获取时间封装成字符串
        String string = new String(event.getBody());

        # 判断数据中是否存在hello,如果存在封装键值对，type-yes，type就是header
        if (string.contains("hello")) {
            event.getHeaders().put("type", "yes");
        } else {
            event.getHeaders().put("type", "no");
        }

        return event;
    }

    # 操纵事件集合
    @Override
    public List<Event> intercept(List<Event> list) {
        # 将上一次的集合清空
        list_event.clear();
        for (Event event : list) {
            # 调用上面的方法，将数据加工头部，存到list中
            list_event.add(intercept(event));
        }
        return list_event;
    }

    @Override
    public void close() {

    }

    public static class Builder implements Interceptor.Builder {

        @Override
        public Interceptor build() {
            return new MyInterceptor();
        }

        @Override
        public void configure(Context context) {

        }
    }
}