OneToManyResultSetExtractorTest.java

/*
 * Copyright 2008-2014 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.data.jdbc.core;

import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.jdbc.core.domain.Address;
import org.springframework.data.jdbc.core.domain.Customer;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.test.annotation.DirtiesContext;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import javax.sql.DataSource;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;

@ContextConfiguration(locations="classpath:core-context.xml")
@RunWith(SpringJUnit4ClassRunner.class)
@DirtiesContext
public class OneToManyResultSetExtractorTest {

	@Autowired
	DataSource dataSource;

	JdbcTemplate template;

	OneToManyResultSetExtractor<Customer, Address, Integer> resultSetExtractor;

	@Before
	public void before() {
		template = new JdbcTemplate(dataSource);
		resultSetExtractor = new CustomerAddressExtractor();
	}

	@Test
	public void testExtractingData() {
		List<Customer> result = template.query(
				"select customer.id, customer.name, address.id, " +
				"address.customer_id, address.street, address.city " +
				"from customer " +
				"left join address on customer.id = address.customer_id " +
				"order by customer.id",
				resultSetExtractor);
		Assert.assertEquals(3, result.size());
		Assert.assertEquals(Integer.valueOf(1), result.get(0).getId());
		Assert.assertEquals(2, result.get(0).getAddresses().size());
		Assert.assertEquals(Integer.valueOf(2), result.get(1).getId());
		Assert.assertEquals(1, result.get(1).getAddresses().size());
		Assert.assertEquals(Integer.valueOf(3), result.get(2).getId());
		Assert.assertEquals(0, result.get(2).getAddresses().size());
		System.out.println(result);
		List<Customer> result2 = template.query(
				"select customer.id, customer.name, address.id, " +
						"address.customer_id, address.street, address.city " +
						"from customer " +
						"left join address on customer.id = address.customer_id " +
						"order by customer.id",
				resultSetExtractor);
		System.out.println(result2);
		Assert.assertEquals(3, result2.size());
	}

	public class CustomerAddressExtractor extends
			OneToManyResultSetExtractor<Customer, Address, Integer> {

		public CustomerAddressExtractor() {
			super(new CustomerMapper(), new AddressMapper());
		}

		@Override
		protected Integer mapPrimaryKey(ResultSet rs) throws SQLException {
			return rs.getInt("customer.id");
		}

		@Override
		protected Integer mapForeignKey(ResultSet rs) throws SQLException {
			if (rs.getObject("address.customer_id") == null) {
				return null;
			}
			else {
				return rs.getInt("address.customer_id");
			}
		}

		@Override
		protected void addChild(Customer root, Address child) {
			root.addAddress(child);
		}
	}

	private static class CustomerMapper implements RowMapper<Customer> {

		public Customer mapRow(ResultSet rs, int rowNum) throws SQLException {
			Customer c = new Customer();
			c.setId(rs.getInt("customer.id"));
			c.setName(rs.getString("customer.name"));
			return c;
		}
	}

	private static class AddressMapper implements RowMapper<Address> {

		public Address mapRow(ResultSet rs, int rowNum) throws SQLException {
			Address a = new Address();
			a.setId(rs.getInt("address.id"));
			a.setStreet(rs.getString("address.street"));
			a.setCity(rs.getString("address.city"));
			return a;
		}
	}
}