Re: data enrichment via endpoint, serializable issue

Posted by Xingcan Cui on
URL: http://deprecated-apache-flink-user-mailing-list-archive.369.s1.nabble.com/data-enrichment-via-endpoint-serializable-issue-tp21629p21633.html

Hi Steffen,

You could make the class `TextAPIClient` serializable, or use `RichMapFunction` [1] and instantiate all the required objects in its `open()` method.

[1] https://ci.apache.org/projects/flink/flink-docs-master/dev/api_concepts.html#rich-functions

Best,

Xingcan

On Jul 19, 2018, at 6:56 PM, Steffen Wohlers <[hidden email]> wrote:

Hi all,

I’m new to Apache Flink and I have the following issue:

I would like to enrich data via map function. For that I call a method which calls an endpoint but I get following error message 

„The implementation of the MapFunction is not serializable. The object probably contains or references non serializable fields.

at org.apache.flink.api.java.ClosureCleaner.clean(ClosureCleaner.java:99)“ …

„Caused by: java.io.NotSerializableException: com.aylien.textapi.TextAPIClient“

Is there a smart way to fix that issue?

Regards,

Steffen

Map Function:

DataStream<TweetSentiment> tweetSentimentDataStream = noRTDataStream
        .map(new MapFunction<Tweet, TweetSentiment>() {
            @Override
            public TweetSentiment map(Tweet tweet) throws Exception {
                String polarity = "good";
                polarity = test.testMethod();
                polarity =  sentimentAnalysis.sentiment(tweet.getText());
                return new TweetSentiment(tweet, polarity, 0);
            }
        });

Class:

public class SentimentAnalysis implements Serializable {

    private TextAPIClient _sentimentClient;

    public SentimentAnalysis () {
        _sentimentClient = new TextAPIClient(„xxx", „xxx");
    }

    public String sentiment(String text)  throws Exception{
        SentimentParams sentimentParams = new SentimentParams(text, null, null);
        Sentiment sentiment = _sentimentClient.sentiment(sentimentParams);

        return sentiment.getPolarity();
    }

(Analysis via Aylien)