title: java.lang.NoClassDefFoundError: org/apache/commons/lang3/ObjectUtils
body: <p>I'm trying to code a program to read a CSV file and then make some stuff with it. 
  I've searching a lot, and finally I found out <a href="http://opencsv.sourceforge.net/" rel="noreferrer">this</a> library. </p>
  
  <p>Some days ago I finished the code, and everything worked fine. Today I updated the library to the 4.0 v, and then a lot of warnings popped out.</p>
  
  <p>I made some testing and the part that fails is: </p>
  
  <pre><code>public void LeerCSV(File CSVCat, File CSVProd){  
  //Creo un objeto de la clase FileReader que me hace falta para los CSVReader
  CSVReaderBuilder lectorCatBuilder = null;
  CSVReaderBuilder lectorProdBuilder = null;
  
  CSVReader CatReader = null;
  CSVReader ProdReader = null;
  
  CSVParser CatParser = null;
  CSVParser ProdParser = null;
          //Vamos a intentar abrirlos y operar con ellos 
  
  try {
      //Se crea una especie de "constructor" para crear los lectores de archivos.
      //para ello, antes se le pasan todos los atributos que queramos        
  
     CatParser =
     new CSVParserBuilder()
     .withSeparator(SEPARADOR)
     .withIgnoreQuotations(true)
     .build();
     CatReader =
     new CSVReaderBuilder(new FileReader(CSVCat))
     .withSkipLines(1)
     .withCSVParser(CatParser)
     .build();
  
     ProdParser =
     new CSVParserBuilder()
     .withSeparator(SEPARADOR)
     .withIgnoreQuotations(true)
     .build();
     ProdReader =
     new CSVReaderBuilder(new FileReader(CSVProd))
     .withSkipLines(1)
     .withCSVParser(ProdParser)
     .build();
  </code></pre>
  
  <p>This one. </p>
  
  <p>The warnings are: </p>
  
  <pre><code>Exception in thread "AWT-EventQueue-0" java.lang.NoClassDefFoundError: 
  org/apache/commons/lang3/ObjectUtils
  at com.opencsv.CSVParser.&lt;init&gt;(CSVParser.java:207)
  at com.opencsv.CSVParserBuilder.build(CSVParserBuilder.java:138)
  ...
  ...
  Caused by: java.lang.ClassNotFoundException: 
  org.apache.commons.lang3.ObjectUtils
  at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
  at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
  </code></pre>
  
  <p>This ones. </p>
  
  <p>I know that is a library problem but I don't know what library is causing it, or if I need to update or install something. </p>
  
  <p>Thank you very much. </p>