net.sf.jstuff.integration.persistence.spring.BeanResultSetExtractor Maven / Gradle / Ivy

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/*
 * Copyright 2010-2022 by Sebastian Thomschke and contributors.
 * SPDX-License-Identifier: EPL-2.0
 */
package net.sf.jstuff.integration.persistence.spring;

import static net.sf.jstuff.core.validation.NullAnalysisHelper.*;

import java.beans.BeanInfo;
import java.beans.IntrospectionException;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.commons.beanutils.BeanUtils;
import org.apache.commons.beanutils.DynaBean;
import org.apache.commons.beanutils.DynaProperty;
import org.apache.commons.beanutils.ResultSetDynaClass;
import org.eclipse.jdt.annotation.Nullable;
import org.springframework.dao.DataAccessException;
import org.springframework.jdbc.core.ResultSetExtractor;

import net.sf.jstuff.core.Strings;
import net.sf.jstuff.core.logging.Logger;
import net.sf.jstuff.core.validation.Assert;

/**
 * @author Sebastian Thomschke
 */
public class BeanResultSetExtractor implements ResultSetExtractor> {
   private static final Logger LOG = Logger.create();

   private Class beanClass = lazyNonNull();
   private Map beanPropertiesLowerCase = lazyNonNull();

   public BeanResultSetExtractor(final Class beanClass) throws IntrospectionException {
      setBeanClass(beanClass);
   }

   @Override
   public @Nullable List extractData(final ResultSet resultSet) throws SQLException, DataAccessException {
      Assert.notNull(beanClass, "Property beanClass must be set.");

      final List extractedBeans = new ArrayList<>();

      for (final var it = new ResultSetDynaClass(resultSet, true).iterator(); it.hasNext();) {
         final DynaBean dynaBean = it.next();
         @SuppressWarnings("null")
         T bean = null;
         try {
            bean = this.getBeanClass().getDeclaredConstructor().newInstance();

            for (final DynaProperty dynaProp : dynaBean.getDynaClass().getDynaProperties()) {
               final String dynaPropName = dynaProp.getName();
               final Object dynaPropValue = dynaBean.get(dynaPropName);
               final String beanPropName = beanPropertiesLowerCase.get(dynaPropName);
               BeanUtils.copyProperty(bean, beanPropName, dynaPropValue);
            }
            extractedBeans.add(bean);
         } catch (final Exception ex) {
            LOG.error(ex, "Unexpected error occurred while processing DynaBean.\n beanClass=%s\n bean=%s\n dynaBean=%s", beanClass, Strings
               .toString(bean), Strings.toString(dynaBean));
         }
      }
      return extractedBeans;
   }

   public Class getBeanClass() {
      return beanClass;
   }

   public void setBeanClass(final Class beanClass) throws IntrospectionException {
      final BeanInfo beanInfo = Introspector.getBeanInfo(beanClass);

      final var propsLowerCase = new HashMap();
      for (final PropertyDescriptor prop : beanInfo.getPropertyDescriptors()) {
         final String propName = prop.getName();
         if (propsLowerCase.put(propName.toLowerCase(), propName) != null)
            throw new IllegalStateException("Bean Class " + beanClass.getName()
               + " contains multiple properties with same lowercase representation: " + propName);
      }

      this.beanClass = beanClass;
      this.beanPropertiesLowerCase = propsLowerCase;
   }
}