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Validating CSV Files

What is CsvValidator ?
  A Java framework which validates any CSV files something similar to XML validation using XSD.

Why should I use this ?
  You don't have to use this and in fact its easy to write something your own and also checkout its source code for reference.

Why did I write this ?
  Some of our projects integrate with third party application which exchanges information in CSV files so I thought of writing a generic validator which can be hooked in multiple projects or can be used by QA for integration testing.

What is the license clause ?

Are there any JUnit test cases for me checkout ?
 Yes, source

How to integrate in my existing project ?

Just add the Jar which can be downloaded from here CsvValidator.jar and you are good.

Instantiate CsvValidator constructor which takes these 3 arguements

         // filename is the the file to be validated and here is a sample
        // list - defines all the fields in the above csv file ( a field has index, type, isOptional, regex )
        // last argument is the file delimiter and it can be anything and not just comma

Checkout this sample code 

 public static void main(String[] args) {
        boolean optional = true;
        boolean notOptional = false;

        List list = new ArrayList();
        list.add(new Field(1, Type.NUMBER, notOptional));
        list.add(new Field(2, Type.NUMBER, notOptional));
        list.add(new Field(3, Type.TEXT, notOptional));
        list.add(new Field(4, Type.TEXT, notOptional));
        list.add(new Field(5, Type.NUMBER, notOptional));
        list.add(new Field(6, "Purchase Date", Type.DATE, notOptional, "yyyy-MM-dd HH:mm:ss"));
        list.add(new Field(7, Type.NUMBER, notOptional));
        list.add(new Field(8, Type.NUMBER, notOptional));
        list.add(new Field(9, "Campaign ID", Type.TEXT, optional));
        list.add(new Field(10, "Promo Code", Type.TEXT, optional));
        list.add(new Field(11, Type.TEXT, notOptional));
        list.add(new Field(12, Type.NUMBER, optional));
        list.add(new Field(13, Type.NUMBER, optional));
        list.add(new Field(14, Type.TEXT, notOptional));

        CsvValidator validator1 = new CsvValidatorImpl("somefile.txt", list, "\\|");

        if (!validator1.isValid()) {


Can my QA use it in a stand alone mode ?
 Yes, just checkout the spec.txt file which your QA needs to create.

java -jar "CsvValidator.jar" csv-file.txt spec.txt

first line in spec.txt is the delimiter (, ' | etc)
  All other lines contains each field information on a separate line for example
    Date of Purchase,D,R,yyyy-MM-dd HH:mm:ss

    first column - field name helps in understanding validation results 
    second column - type (T, N, D ) represents Text, Number, Date
    third column - Required (R, O) represents Required or Optional
    fourth column - regex 

  (Regex for dates )
"yyyy.MM.dd G 'at' HH:mm:ss z"2001.07.04 AD at 12:08:56 PDT
"EEE, MMM d, ''yy"Wed, Jul 4, '01
"h:mm a"12:08 PM
"hh 'o''clock' a, zzzz"12 o'clock PM, Pacific Daylight Time
"K:mm a, z"0:08 PM, PDT
"yyyyy.MMMMM.dd GGG hh:mm aaa"02001.July.04 AD 12:08 PM
"EEE, d MMM yyyy HH:mm:ss Z"Wed, 4 Jul 2001 12:08:56 -0700

 Regex cheat sheet for all others cheat sheet


Anonymous said…
Excellent article and easy to understand explanation. How do I go about getting permission to post part of the article in my upcoming news letter? Giving proper credit to you the author and link to the site would not be a problem.
Anonymous said…
In my csv some headers are created dynamically, i.e they are unknown at compile time. Is there any way to validate those field using CsvValidator?
vijay krishna said…
Can you share gradle build path for this jar
Unknown said…
Your post is really awesome. Your blog is really helpful for me to develop my skills in a right way. Thanks for sharing this unique information with us.
- Learn Digital Academy

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