CODEWITHSUNDEEP
regexminifyapache-nifihortonworks-data-platformhortonworks-dataflow
Rishab Prasad
Rishab Prasad

Reputation: 951

Regular expression to extract comma separated values?

I am trying to read values from a csv file and then store the values into attributes using ExtractText processor. The file contains only one line, which has 5 values separated by comma. Here is the content of my file:

jdbc:mysql://localhost:3306/test, com.mysql.jdbc.Driver, C:\ProgramFiles\MySQL\mysql-connector.jar, root, root

I have manually added 5 properties in the ExtractText processor:- 

DatabaseConnectionURL
DatabaseDriverClass
DatabaseDriverLocation
DatabaseUser
Password

Now, I want regular expressions for the above 5 attributes that I have defined in the ExtractText processor so that they get the following value:-

DatabaseConnectionURL = jdbc:mysql://localhost:3306/test
DatabaseDriverClass = com.mysql.jdbc.Driver
DatabaseDriverLocation = C:\Program Files\MySQL\mysql-connector.jar
DatabaseUser = root
Password = root

Can you please provide me the regular expression for the above 5 attributes?

Upvotes: 3

Views: 1591

Answers (1)

Mahendran V M
Mahendran V M

Reputation: 3496

Rishab,

You the ExtractText processor with the following regular expression to capture lines.

ExtractedData:(^.*$)

Then use updateAttribute with getDelimitedField() expression as demonstrated below to assign values to flow file attributes.

DatabaseConnectionURL:${ExtractedData:getDelimitedField(1)}

DatabaseDriverClass:${ExtractedData:getDelimitedField(2)}

DatabaseDriverLocation:${ExtractedData:getDelimitedField(3)}

DatabaseUser:${ExtractedData:getDelimitedField(4)}

Password:${ExtractedData:getDelimitedField(5)}

getDelimitedField() "Parses the Subject as a delimited line of text and returns just a single field from that delimited text." and can be used on any configuration property that supports NiFi's expression language. For detailed getDelimitedField() explanation, view the NiFi Expression Language guide.

https://nifi.apache.org/docs/nifi-docs/html/expression-language-guide.html#getdelimitedfield

Hope this solution helps solve your problem.

Don't forget to accept if it worked and let me know if you run into any issues.

Upvotes: 4

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