CODEWITHSUNDEEP
javastringnullequals
user5447339
user5447339

Reputation:

Is there any built in utility to check for "null" String instead of null?

I am extracting a variable value from Apache Avro GenericRecord so my String variable value is coming as "null" instead of null.

GenericRecord payload = decoder.decode(record.value());
String userid = String.valueOf(payload.get("userId"));
// here userid is null string as "null"
System.out.println(Strings.isNullOrEmpty(userid));

And because of that "null" string, my sysout prints out as false. How can I check this so that it prints out as "true" bcoz string was a null string. Is there any built in utitilty which does that or I have to write my own ".equals" check?

Upvotes: 1

Views: 403

Answers (2)

nail fei
nail fei

Reputation: 2319

"null" is a plain string type, just use the API of String type: .equals("null") is ok.

Upvotes: 1

Stefan Dollase
Stefan Dollase

Reputation: 4620

You probably generate the "null" String by yourself with the String.valueOf(...) method. From the JavaDoc of String#valueOf:

Returns: if the argument is null, then a string equal to "null"; otherwise, the value of obj.toString() is returned.

Thus, I suggest to use the following code:

    GenericRecord payload = decoder.decode(record.value());
    boolean isNull = payload.get("userId") == null;
    if (!isNull) {
        String userid = payload.get("userId").toString();
    }

This prevents the problem of comparing with the "null" String by not generating it.

Upvotes: 1

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