Package com.opencsv.validators

Class RowFunctionValidator

  • All Implemented Interfaces:
    RowValidator
    public class RowFunctionValidator
extends java.lang.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 Summary

      Fields 
      Modifier and Type Field Description
      private java.lang.String failureMessage  
      private java.util.function.Function<java.lang.String[],​java.lang.Boolean> testFunction  

    • Constructor Summary

      Constructors 
      Constructor Description
      RowFunctionValidator​(java.util.function.Function<java.lang.String[],​java.lang.Boolean> testFunction, java.lang.String failureMessage)
      Default Constructor.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      boolean isValid​(java.lang.String[] row)
      Performs the validation check on the string and returns the result.
      void validate​(java.lang.String[] row)
      Performs the validation check on the row (an array of Strings) and throws an exception if invalid.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Field Detail

      • testFunction

        private java.util.function.Function<java.lang.String[],​java.lang.Boolean> testFunction

      • failureMessage

        private java.lang.String failureMessage

    • Constructor Detail

      • RowFunctionValidator

        public RowFunctionValidator​(java.util.function.Function<java.lang.String[],​java.lang.Boolean> testFunction,
                            java.lang.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 Detail

      • isValid

        public boolean isValid​(java.lang.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​(java.lang.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.