Using the previous DAO and service layer, let us implement a Spring Boot 2.0 application by doing the following steps:

1. Open pom.xml and add the following starter for the Spring Boot application:

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

2. Add the MySQL connector for the JDBC connectivity:

<dependency> 
      <groupId>mysql</groupId> 
      <artifactId>mysql-connector-java</artifactId> 
      <version>5.1.40</version> 
</dependency> 

3. Open the application.properties and add the following properties for the org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration class:

spring.datasource.driverClassName=com.mysql.jdbc.Driver 
spring.datasource.url=jdbc:mysql://localhost:3306/hrs?autoReconnect=true&useSSL=true&serverSslCert=classpath:config/spring5packt.crt 
spring.datasource.username=root 
spring.datasource.password=spring5mysql 
spring.datasource.hikari.connection-timeout=60000 
spring.datasource.hikari.maximum-pool-size=5 

4. Create a new package org.packt.spring.boot.model.data and copy into it all data models from Chapter 8, Reactive Web Applications.
5. Copy to org.packt.spring.boot.dao all the DAO interfaces from the previous chapter.
6. Copy the DAO implementation classes from Chapter 8, Reactive Web Applications, to a new package org.packt.spring.boot.dao.impl.
7. Since Spring Boot does no longer uses lots of annotations, there will be some modifications in the DAO implementation classes. Instead of auto-wiring objects, Spring Boot is capable of injecting @Bean to the constructor of any component. Thus the auto-configured java.sql.DataSource will be automatically injected to a constructor of any DAO implementation with a parameter as such. Follow the modifications of EmplayeeDaoImpl and DepartmentDaoImpl as follows:

@Repository 
public class DepartmentDaoImpl implements DepartmentDao{ 
   private JdbcTemplate jdbcTemplate; 
   private SimpleJdbcInsert jdbcInsert; 
    
   public DepartmentDaoImpl(DataSource dataSource) { 
      jdbcTemplate = new JdbcTemplate(dataSource); 
      jdbcInsert = new SimpleJdbcInsert(jdbcTemplate); 
} 
// refer to sources 
} 
 
@Repository 
public class EmployeeDaoImpl implements EmployeeDao { 
   private JdbcTemplate jdbcTemplate; 
   private SimpleJdbcInsert jdbcInsert; 
    
   public EmployeeDaoImpl(DataSource dataSource) { 
      jdbcTemplate = new JdbcTemplate(dataSource); 
      jdbcInsert = new SimpleJdbcInsert(jdbcTemplate); 
} 
// refer to sources 
} 

8. Save all files. Then clean and install. Generate the WAR file.