com.opencsv.validators.RowMustHaveSameNumberOfColumnsAsFirstRowValidator Maven / Gradle / Ivy
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package com.opencsv.validators;
import com.opencsv.exceptions.CsvValidationException;
/**
* This validator is used when the number of columns is not neccessarily known but must be consistent.
* The first row validated will always be considered valid, unless null or empty, and after that the each
* subsequent row must have the same number of columns as the first.
*
* Arrays that are empty or null are considered to have 0 elements. 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. If you have data that has empty lines or separators lines in your data then you should not
* use this class. Either extend it or write your own validator.
*
* @author Scott Conway
* @since 5.0
*/
public class RowMustHaveSameNumberOfColumnsAsFirstRowValidator implements RowValidator {
private static final int NO_ROWS = 0;
private int numRows = NO_ROWS;
/**
* Default constructor.
*/
public RowMustHaveSameNumberOfColumnsAsFirstRowValidator() {
}
@Override
public boolean isValid(String[] row) {
if (row == null || row.length == 0) {
return false;
}
if (firstRowNotSetYet()) {
numRows = row.length;
}
return row.length == numRows;
}
@Override
public void validate(String[] row) throws CsvValidationException {
if (!isValid(row)) {
if (firstRowNotSetYet()) {
throw new CsvValidationException("First row should not be empty or null");
} else if (row == null || row.length == 0) {
throw new CsvValidationException("Row should not be empty or null");
} else {
throw new CsvValidationException(String.format("Row was expected to have %d elements but had %d instead", numRows, row.length));
}
}
}
private boolean firstRowNotSetYet() {
return numRows == NO_ROWS;
}
}