Skip to main content

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
afiah ahamed said…
Thank you a lot for providing individuals with a very spectacular possibility to read critical reviews from this site.
Java training in Chennai

Java training in Bangalore
jeeva said…
Very nice post here and thanks for it .I always like and such a super contents of these post.Excellent and very cool idea and great content of different kinds of the valuable information's.
rpa training in bangalore
best rpa training in bangalore
RPA training in bangalore
rpa course in bangalore
rpa training in chennai
rpa online training
john jersy said…
The knowledge of technology you have been sharing thorough this post is very much helpful to develop new idea. here by i also want to share this.
python training in chennai
python course in chennai
python training in bangalore
sasitamil said…
I found your blog while searching for the updates, I am happy to be here. Very useful content and also easily understandable providing..
Believe me I did wrote an post about tutorials for beginners with reference of your blog. 

Selenium training in bangalore
Selenium training in Chennai
Selenium training in Bangalore
Selenium training in Pune
Selenium Online training

Popular posts from this blog

JPA 2 new feature @ElementCollection explained

@ElementCollection is new annotation introduced in JPA 2.0, This will help us get rid of One-Many and Many-One shitty syntax.

Example 1: Stores list of Strings in an Entity

public class Users implements Serializable {

    private static final long serialVersionUID = 1L;
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;
    private List<String> certifications = new ArrayList<String>();

    public Long getId() {
        return id;

    public void setId(Long id) { = id;

    public List<String> getCertifications() {
        return certifications;

    public void setCertifications(List<String> certifications) {
        this.certifications = certifications;

        Users u = new Users();
        u.getCertifications().add("Sun Certified Java Programmer");

Generated Tables

Column --> ID
    Row             1