title: Jasper iReport: Error retrieving field value from bean
body: <p>I am trying to pass list of days from bean to jasper plugin in Netbeans but i get an error.
  I have followed this guide <a href="http://javabeansinjasper.blogspot.cz/2011/01/javabeans-as-datasource-in.html#comment-form" rel="nofollow">http://javabeansinjasper.blogspot.cz/2011/01/javabeans-as-datasource-in.html#comment-form</a></p>
  
  <p>Error:</p>
  
  <pre><code>Error filling print... Error retrieving field value from bean : den 
  net.sf.jasperreports.engine.JRException: Error retrieving field value from bean : den      
  at net.sf.jasperreports.engine.data.JRAbstractBeanDataSource.getBeanProperty(JRAbstractBeanDataSource.java:123)      
  at net.sf.jasperreports.engine.data.JRAbstractBeanDataSource.getFieldValue(JRAbstractBeanDataSource.java:96)      
  at net.sf.jasperreports.engine.data.JRBeanCollectionDataSource.getFieldValue(JRBeanCollectionDataSource.java:109)      
  at net.sf.jasperreports.engine.fill.JRFillDataset.setOldValues(JRFillDataset.java:1358)      
  at net.sf.jasperreports.engine.fill.JRFillDataset.next(JRFillDataset.java:1259)      
  at net.sf.jasperreports.engine.fill.JRFillDataset.next(JRFillDataset.java:1235)      
  at net.sf.jasperreports.engine.fill.JRBaseFiller.next(JRBaseFiller.java:1614)      
  at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillReport(JRVerticalFiller.java:150)      
  at net.sf.jasperreports.engine.fill.JRBaseFiller.fill(JRBaseFiller.java:963)      
  at net.sf.jasperreports.engine.fill.JRBaseFiller.fill(JRBaseFiller.java:892)      
  at net.sf.jasperreports.engine.fill.JRFiller.fill(JRFiller.java:114)      
  at net.sf.jasperreports.engine.JasperFillManager.fill(JasperFillManager.java:584)      
  at net.sf.jasperreports.engine.JasperFillManager.fillReport(JasperFillManager.java:930)      
  at com.jaspersoft.ireport.designer.compiler.IReportCompiler.run(IReportCompiler.java:928)      
  at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1423)      
  at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:2033)  
  Caused by: java.lang.NoSuchMethodException: Unknown property 'den' on class 'class java.lang.String'      
  at org.apache.commons.beanutils.PropertyUtilsBean.getSimpleProperty(PropertyUtilsBean.java:1322)      
  at org.apache.commons.beanutils.PropertyUtilsBean.getNestedProperty(PropertyUtilsBean.java:770)      
  at org.apache.commons.beanutils.PropertyUtilsBean.getProperty(PropertyUtilsBean.java:846)      
  at org.apache.commons.beanutils.PropertyUtils.getProperty(PropertyUtils.java:426)      
  at net.sf.jasperreports.engine.data.JRAbstractBeanDataSource.getBeanProperty(JRAbstractBeanDataSource.java:111)      ... 15 more 
  </code></pre>
  
  <p>Here is a bean:</p>
  
  <pre><code>public class ListDays {
  
  public ListDays(String den) {
      this.den = den;
  }
  
  public ListDays() {
  }
  
  public String den;
  
  public String getDen() {
      return den;
  }
  
  public void setDen(String den) {
      this.den = den;
  }
  
  public static Collection getSeznamDnu(){
      List&lt;String&gt; seznamDnu = new ArrayList&lt;&gt;();
      try {
          for (int i = 0; i&lt;LocalDate.now().getMonth().length(LocalDate.now().isLeapYear()) ;i++){
              LocalDate prvniDenMesice = LocalDate.now().withDayOfMonth(1);
              seznamDnu.add(prvniDenMesice.plusDays(i).format(DateTimeFormatter.ofPattern("EE dd")));}
      } catch (Exception e) {
          System.out.println(e);
      }
      return seznamDnu;
  
  }
  </code></pre>
  
  <p>}</p>
  
  <p>And here is a report:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;jasperReport xmlns="http://jasperreports.sourceforge.net/jasperreports" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://jasperreports.sourceforge.net/jasperreports http://jasperreports.sourceforge.net/xsd/jasperreport.xsd" name="null" pageWidth="595" pageHeight="842" columnWidth="555" leftMargin="20" rightMargin="20" topMargin="20" bottomMargin="20" uuid="0f6a9791-50d4-4aff-9b3f-da0e5f528443"&gt;
      &lt;property name="ireport.zoom" value="1.0"/&gt;
      &lt;property name="ireport.x" value="0"/&gt;
      &lt;property name="ireport.y" value="0"/&gt;
      &lt;queryString&gt;
          &lt;![CDATA[]]&gt;
      &lt;/queryString&gt;
      &lt;field name="den" class="java.lang.String"&gt;
          &lt;fieldDescription&gt;&lt;![CDATA[den]]&gt;&lt;/fieldDescription&gt;
      &lt;/field&gt;
      &lt;background&gt;
          &lt;band splitType="Stretch"/&gt;
      &lt;/background&gt;
      &lt;title&gt;
          &lt;band height="79" splitType="Stretch"/&gt;
      &lt;/title&gt;
      &lt;pageHeader&gt;
          &lt;band height="35" splitType="Stretch"/&gt;
      &lt;/pageHeader&gt;
      &lt;columnHeader&gt;
          &lt;band height="61" splitType="Stretch"&gt;
              &lt;staticText&gt;
                  &lt;reportElement x="113" y="2" width="100" height="20" uuid="6b5fe0c5-60a2-4db6-96d6-cb9d065e17ff"/&gt;
                  &lt;text&gt;&lt;![CDATA[den]]&gt;&lt;/text&gt;
              &lt;/staticText&gt;
          &lt;/band&gt;
      &lt;/columnHeader&gt;
      &lt;detail&gt;
          &lt;band height="125" splitType="Stretch"&gt;
              &lt;textField&gt;
                  &lt;reportElement x="113" y="29" width="100" height="20" uuid="f588ecab-7ede-4e2c-80b9-994efcc45dd8"/&gt;
                  &lt;textFieldExpression&gt;&lt;![CDATA[$F{den}]]&gt;&lt;/textFieldExpression&gt;
              &lt;/textField&gt;
          &lt;/band&gt;
      &lt;/detail&gt;
      &lt;columnFooter&gt;
          &lt;band height="45" splitType="Stretch"/&gt;
      &lt;/columnFooter&gt;
      &lt;pageFooter&gt;
          &lt;band height="54" splitType="Stretch"/&gt;
      &lt;/pageFooter&gt;
      &lt;summary&gt;
          &lt;band height="42" splitType="Stretch"/&gt;
      &lt;/summary&gt;
  &lt;/jasperReport&gt;
  </code></pre>
  
  <p>Thanks in advance. Been stacked on this for quite some time. Hopefully question is understandable.</p>