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I'm trying to get the value of the tuple by the String but when i'm doing it getting an error saying

 incompatible types: java.lang.Object cannot be converted to java.lang.String

this is how I'm Trying.

 `  public void execute(Tuple tuple) {
  String field = tuple.getValueByField("name");

        for(String user:field.split(","))}`

I tried like this by casting the string

String field = (String) tuple.getValueByField("name");

Is this a correct way to get the value of the tuple by the field name?

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  • 1
    Which Tuple class are you using? Commented Feb 23, 2016 at 5:01
  • yes it is correct, if return type is string. Are you getting any error on (String) tuple.getValueByField("name"); ? Commented Feb 23, 2016 at 5:04

4 Answers 4

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2

Use 

tuple.getStringByField("name");

getStringByField is used to retrieve the value, based on column name.

Apache storm Documentation

what is use of Tuple.getStringByField(“ABC”) in Storm

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1

try using getStringByField instead

if you want to use getValueByField then you will need to check if (obj instanceof String) then cast it

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1

yes it is correct, if return type is string.

String field = (String) tuple.getValueByField("name");

See example for reference

http://www.programcreek.com/java-api-examples/index.php?class=backtype.storm.tuple.Tuple&method=getValueByField

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-1

Try this... 

String field = String.valueOf(tuple.getValueByField("name"));

instead of

String field = (String) tuple.getValueByField("name");
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