data.sql

insert into states_afflictions values('Texas', 'tornadoes', 'Oklahoma', 'tornadoes', 'Arkansas', 'floods'); 
insert into states_afflictions values('Idaho', 'potato famine', 'Texas', 'rodeos', 'Lousiana', 'hurricanes');
insert into states_afflictions values('Arkansas', 'cotton', 'Louisiana', 'mosquitoes', 'Texas', 'hurricanes');
insert into states_afflictions values('Texas', 'heat', 'Texas', 'drought', 'Florida', 'hurricanes');

KeyValueGetter.java

package com.example;
import org.slf4j.*;
import java.sql.*;
import java.util.stream.Collectors;
import org.apache.commons.collections4.*;
import org.apache.commons.collections4.multimap.*;
import org.springframework.dao.DataAccessException;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.ResultSetExtractor;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.*;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.Bean;

@EnableAutoConfiguration
public class KeyValueGetter implements CommandLineRunner {
	private static final Logger log = LoggerFactory.getLogger(KeyValueGetter.class);
	ArrayListValuedHashMap keyvals = new ArrayListValuedHashMap();
	
	@Autowired
	JdbcTemplate jdbcTemplate;
	String sql = new StringBuilder().append("select key1, prop1 from states_afflictions where key1 = ? UNION")
		.append(" select key2, prop2 from states_afflictions where key2 = ? UNION")
		.append(" select key3, prop3 from states_afflictions where key3 = ?").toString();
	
	public static void main(String... args) {
		SpringApplication.run(KeyValueGetter.class, args);
	}
		
	@Override 
	public void run(String... args) throws Exception {
		jdbcTemplate.query(sql, new Object[] {"Texas", "Texas", "Texas"},
		    (rs, rownum) -> keyvals.put(rs.getString(1), rs.getString(2)));
		MapIterator mit = keyvals.mapIterator();
		while(mit.hasNext()) {
			mit.next();
			log.error("keyval = " + mit.getKey() + ", " + mit.getValue());
		}
	}
}

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.3.2.RELEASE</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>
	
	<groupId>com.example</groupId>
	<artifactId>key-value-getter</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<name>KeyValueGetter</name>

	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
		<java.version>1.8</java.version>
	</properties>

	<dependencies>
		<dependency>
			<groupId>org.apache.commons</groupId>
			<artifactId>commons-collections4</artifactId>
			<version>4.1</version>
		</dependency>
		
		<dependency>
			<groupId>com.h2database</groupId>
			<artifactId>h2</artifactId>
			<scope>runtime</scope>
		</dependency>
	
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-data-jdbc</artifactId>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
	</dependencies>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
			<plugin>
				<groupId>org.apache.maven.plugins</groupId>
				<artifactId>maven-surefire-plugin</artifactId>
				<configuration>
					<includes>
						<include>**/*Test*.java</include>
					</includes>
				</configuration>
			</plugin>
		</plugins>
	</build>


</project>

schema.sql

create table states_afflictions(key1 CHAR(10), prop1 VARCHAR(20), key2 CHAR(10), prop2 VARCHAR(20), key3 CHAR(10), prop3 VARCHAR(20));