Class RowFunctionValidator

java.lang.Object
com.opencsv.validators.RowFunctionValidator
All Implemented Interfaces:
RowValidator

public class RowFunctionValidator extends Object implements RowValidator
This validator is best used to validate a specific property of the row - either about a specific element or information about the array itself.

An empty or null first row is considered invalid.

As with all row validators the assumption is you have control of the data and have skipped any initial empty lines AND that your validator checks the size or handles the IndexOutOfBoundsException.

There are several examples coded in the RowFunctionValidatorTest but here are a couple to give you the idea of the flexibility this validator offers.


     private static final String[] GOOD_ROW = {"8675309", "Firstname", "M", "Lastname", "Dec 06, 1951"};
     private static final String[] BAD_ROW = {"not a number", "not capitialized", "not an initial", "Not Single word", "12/06/51"};
     private static final String[] LONG_ROW = {"8675309", "Firstname", "M", "Lastname", "Dec 06, 1951", "More data"};
     private static final String[] SHORT_ROW = {"8675309", "Firstname", "Lastname", "Dec 06, 1951"};

     private static final Function<String[], Boolean> THIRD_ELEMENT_IS_MIDDLE_INITIAL = (x) -> {
         return x.length > 2 && x[2].matches("^[A-Z]$");
     };

     private static final Function<String[], Boolean> ROW_MUST_HAVE_FIVE_ELEMENTS = (x) -> {
         return (x.length == 5);
     };
 
    @Test
    @DisplayName("Simple test to show checking an middle initial")
    public void thirdElementIsMiddleInitial() {
         validator = new RowFunctionValidator(THIRD_ELEMENT_IS_MIDDLE_INITIAL, "The third element must be the middle initial.");

         assertTrue(validator.isValid(GOOD_ROW));
         assertFalse(validator.isValid(BAD_ROW));
     }
 
    @Test
    @DisplayName("The row must have a specific number of elements in order to be valid.")
    public void numberOfElementsInARow() {
         validator = new RowFunctionValidator(ROW_MUST_HAVE_FIVE_ELEMENTS, "A Row can have only five elements.");

         assertTrue(validator.isValid(GOOD_ROW));
         assertFalse(validator.isValid(LONG_ROW));
         assertFalse(validator.isValid(SHORT_ROW));
     }
 
Since:
5.0
  • Field Details

  • Constructor Details

    • RowFunctionValidator

      public RowFunctionValidator(Function<String[],Boolean> testFunction, String failureMessage)
      Default Constructor.
      Parameters:
      testFunction - - function to run against the Array of Strings.
      failureMessage - - message to be included in the CsvValidationException error message.
  • Method Details

    • isValid

      public boolean isValid(String[] row)
      Description copied from interface: RowValidator
      Performs the validation check on the string and returns the result. While not called directly in opencsv it is in the interface to provide an easy way to test if the validator is functioning properly.
      Specified by:
      isValid in interface RowValidator
      Parameters:
      row - Array of strings to be validated
      Returns:
      true if the row is valid, false otherwise
    • validate

      public void validate(String[] row) throws CsvValidationException
      Description copied from interface: RowValidator
      Performs the validation check on the row (an array of Strings) and throws an exception if invalid.
      Specified by:
      validate in interface RowValidator
      Parameters:
      row - Array of Strings to be validated.
      Throws:
      CsvValidationException - Thrown if invalid. Should contain a message describing the error.