背景

0点飘移是生产中常见的问题，我按照官网自定义拦截器并部署到生产后，没有起作用，我针对实际业务字段做了代码调整。

修复前

• 代码

package com.cowa.flume;

import com.alibaba.fastjson.JSONObject;
import org.apache.flume.Context;
import org.apache.flume.Event;
import org.apache.flume.interceptor.Interceptor;

import java.nio.charset.StandardCharsets;
import java.util.List;
import java.util.Map;

public class TimeStampInterceptor implements Interceptor {
    @Override
    public void initialize() {

    }
    @Override
    public Event intercept(Event event) {

        Map<String, String> headers = event.getHeaders();

        String log = new String(event.getBody(), StandardCharsets.UTF_8);

        JSONObject jsonObject = JSONObject.parseObject(log);

        String ts = jsonObject.getString("ts");
        headers.put("timestamp", ts);

        return event;
    }
    @Override
    public List<Event> intercept(List<Event> events) {

        for (Event event : events) {
            intercept(event);
        }

        return events;
    }
    @Override
    public void close() {

    }
    public static class Builder implements Interceptor.Builder {
        @Override
        public Interceptor build() {
            return new TimeStampInterceptor();
        }
        @Override
        public void configure(Context context) {
        }
    }
}

• 报错：java.lang.RuntimeException:For Input String :“”
  

修复后

• 代码

package com.cowa.flume;

import com.alibaba.fastjson.JSONObject;
import org.apache.flume.Context;
import org.apache.flume.Event;
import org.apache.flume.interceptor.Interceptor;

import java.nio.charset.StandardCharsets;
import java.util.List;
import java.util.Map;

public class TimeStampInterceptor implements Interceptor {
    @Override
    public void initialize() {

    }
    @Override
    public Event intercept(Event event) {

        Map<String, String> headers = event.getHeaders();

        String log = new String(event.getBody(), StandardCharsets.UTF_8);

        JSONObject jsonObject = JSONObject.parseObject(log);

        String ts = jsonObject.getString("time");
        headers.put("timestamp", ts);

        return event;
    }
    @Override
    public List<Event> intercept(List<Event> events) {

        for (Event event : events) {
            intercept(event);
        }

        return events;
    }
    @Override
    public void close() {

    }
    public static class Builder implements Interceptor.Builder {
        @Override
        public Interceptor build() {
            return new TimeStampInterceptor();
        }
        @Override
        public void configure(Context context) {
        }
    }
}

分析总结

问题出在了 String ts = jsonObject.getString(“ts”);
我数据源中的时间字段名字不是ts，而是time，所以改为如下
String ts = jsonObject.getString(“time”);恢复正常。

！！！大家一定要注意这个小点，不然拦截器获取不到正确的key放入header