package com.opencsv.bean.processor;
   
   /**
    * StringProcessor that converts the empty or blank strings to a literal null string.
    * This is useful when you prefer null in a particular variable.
    * <p>
    * A sample of this can be found in the unit test ProcessorTestBean and is annotated as follows.
    * <p>
    * <pre>
   *     &#64;PreAssignmentProcessor(processor = ConvertEmptyOrBlankStringsToNull.class)
   *     &#64;CsvBindByName(column = "name")
   *     private String beanName;
   *  </pre>
   *
   * @author Scott Conway
   * @since 5.4
   */
  public class ConvertEmptyOrBlankStringsToNull implements StringProcessor {
  
      /**
       * Default Constructor.
       */
      public ConvertEmptyOrBlankStringsToNull() {
      }
  
      @Override
      public String processString(String value) {
          if (value == null || value.trim().isEmpty()) {
              return null;
          }
          return value;
      }
  
      /**
       * This method is unused in this implementation as we are converting to null.
       * Any calls to this method are ignored.
       *
       * @param value Information used by the processor to process the string
       */
      @Override
      public void setParameterString(String value) {
          // not needed
      }
  }