Copying JAXB properties to JPA entities

[Puspender Tanwar]

I am having a requirement where I need to read an data XML file and then send the data to the Oracle DataBase. For this, I am using JAXB to read the XML file and JPA-Hibernate to persist data in DB. By unmarshalling the XML file using JAXB, I got the complete data in a bean, then I copied the Bean's property to the JPA entity bean using Apache BeanUtils and the persists the data using Hibernate. Below is the code:

		List<XxspPoInHeader> instance = new EbsXmlUnmarshaller().unMarshal_PoInHeaderCollection(xmlFile).getXxspPoInHeader();
		XxspPoInHeader xxspPoInHeader = instance.get(0);
		
		com.oracle.model.XxspPoInHeader inHeaderModel = new com.oracle.model.XxspPoInHeader();  //entity class
		
		PurchaseOraderRepo pOraderRepo = new PurchaseOraderRepo();
		
		BeanUtils.copyProperties(inHeaderModel, xxspPoInHeader);
		
		pOraderRepo.save(inHeaderModel);

But while copying the properties from JAXB to JPA entity I am facing an error : org.apache.commons.beanutils.ConversionException: DateConverter does not support default String to 'Date' conversion. Which clearly explains that there is some property in JAXB which is of type 'String' but the same name property is of type 'Date' in JPA entity class. But I don't know how can I handle this situation, as I cannot verify the list of property because there are 900+ property variables in JAXB class.
How can I handle this situation? suggestions please!

[Stefan Evans]

Do you know the valid date format(s) that you will be receiving in the XML?
At some point you need to convert from a String into a Date.

You can do this in the JAXB layer, or with the BeanUtils specifying date formats for the converter.
The important segment:

        DateConverter dateConverter = new DateConverter();
        String[] validDatePatterns = {"dd/MM/yyyy", "MM/dd/yyyy"};
        dateConverter.setPatterns(validDatePatterns);
        ConvertUtils.register(dateConverter, Date.class);

Example test code below:

package test;

import org.apache.commons.beanutils.BeanUtils;
import org.apache.commons.beanutils.ConversionException;
import org.apache.commons.beanutils.ConvertUtils;
import org.apache.commons.beanutils.converters.DateConverter;
import org.junit.Test;

import java.lang.reflect.InvocationTargetException;
import java.util.Calendar;
import java.util.Date;

import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.assertThat;

public class BeanUtilsConverter {

    public class DestObject{
        public Date getBirthday() {
            return birthday;
        }

        public void setBirthday(Date birthday) {
            this.birthday = birthday;
        }

        Date birthday;

        public String getName() {
            return name;
        }

        public void setName(String name) {
            this.name = name;
        }

        String name;


    };

    public class SourceObject{
        public String getBirthday() {
            return birthday;
        }

        public void setBirthday(String birthday) {
            this.birthday = birthday;
        }

        String birthday;

        public String getName() {
            return name;
        }

        public void setName(String name) {
            this.name = name;
        }

        String name;
    }

    @Test
    public void testCopyPropertiesWithConverter() throws InvocationTargetException, IllegalAccessException {

        DestObject destination = new DestObject();
        SourceObject origin = new SourceObject();
        origin.setName("Example");
        origin.setBirthday("04/07/2000");

        DateConverter dateConverter = new DateConverter();
        String[] validDatePatterns = {"dd/MM/yyyy", "MM/dd/yyyy"};
        dateConverter.setPatterns(validDatePatterns);
        ConvertUtils.register(dateConverter, Date.class);

        BeanUtils.copyProperties(destination, origin);

        Calendar cal = Calendar.getInstance();
        cal.clear();
        cal.set(Calendar.YEAR, 2000);
        cal.set(Calendar.MONTH, Calendar.JULY);
        cal.set(Calendar.DATE, 4);

        assertThat(destination.getName(), is("Example"));
        assertThat(destination.getBirthday(), is(cal.getTime()));
    }

    @Test(expected = ConversionException.class)
    public void testCopyPropertiesWithoutConverter() throws InvocationTargetException, IllegalAccessException {

        DestObject destination = new DestObject();
        SourceObject origin = new SourceObject();
        origin.setName("Example");
        origin.setBirthday("04/07/2000");
        BeanUtils.copyProperties(destination, origin);
    }

}