Class to be used as a Transformer in a Spring Integration workflow

BeanPropertySettingTransformer.java

package de.fittransporte.fitdb.util.integration;

import de.fittransporte.fitdb.util.ExpressionUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.BeanWrapper;
import org.springframework.beans.PropertyAccessorFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.convert.ConversionService;
import org.springframework.expression.EvaluationException;
import org.springframework.integration.Message;
import org.springframework.integration.transformer.Transformer;
import org.springframework.util.Assert;

import java.util.Map;

/**
 * Sets properties of the <em>targetObject</em> using the specified <em>propertyMapping</em> with the incoming message.
 * If targetObject is not specified the <em>message.getPayload()</em> is set as <em>targetObject</em>
 *
 * Configuration sample:
 * <pre>
 &lt;int:transformer method="transform"&gt;
   &lt;bean id="mapToSalesOrderPalletsTransformer" class="de.fittransporte.fitdb.util.integration.BeanPropertySettingTransformer"&gt;
     &lt;property name="propertyMapping"&gt;
       &lt;util:map&gt;
         &lt;entry key="salesOrder" value="%{headers['salesorder']}"/&gt;
         &lt;entry key="palletCount" value="%{headers['pallet']['ANZAHL_PALETTEN']}"/&gt;
         &lt;entry key="palletType" value="%{headers['pallet']['PALETTENTYP']}"/&gt;
         &lt;entry key="palletTypeString" value="%{headers['pallet']['PALETTENTYP']}"/&gt;
       &lt;/util:map&gt;
     &lt;/property&gt;
   &lt;/bean&gt;
 &lt;/int:transformer&gt;
 * </pre>
 */
public class BeanPropertySettingTransformer implements Transformer
{
    private static final Logger LOG = LoggerFactory.getLogger(BeanPropertySettingTransformer.class);
    private ConversionService conversionService;

    private Map<String, Object> propertyMapping;
    private Object targetObject;

    @Override
    public Message<?> transform(final Message<?> message)
    {
        Assert.notNull(propertyMapping, "'propertyMapping' must be set beforehand!");

        targetObject = message.getPayload();

        for (String property : propertyMapping.keySet())
        {
            Object propValue = propertyMapping.get(property);
            final BeanWrapper wrapper = PropertyAccessorFactory.forBeanPropertyAccess(targetObject);
            final Class targetType = wrapper.getPropertyType(property);

            if (propValue instanceof String)
            {
                try {
                    propValue = ExpressionUtil.parse((String) propValue, message, conversionService, targetType);
                } catch (EvaluationException evex) 
                {
                    LOG.error("Error evaluating the specified expression", evex);
                    propValue = null;
                }
            }
            wrapper.setPropertyValue(property, propValue);
        }
        return message;
    }


    public void setPropertyMapping(Map<String, Object> propertyMapping)
    {
        this.propertyMapping = propertyMapping;
    }

    public Map<String, Object> getPropertyMapping()
    {
        return propertyMapping;
    }

    public Object getTargetObject()
    {
        return targetObject;
    }

    public void setTargetObject(final Object targetObject)
    {
        this.targetObject = targetObject;
    }

    public ConversionService getConversionService()
    {
        return conversionService;
    }

    @Autowired
    public void setConversionService(final ConversionService conversionService)
    {
        this.conversionService = conversionService;
    }
}