Am trying to do simple JDBC call in a spring boot application is not working - spring-boot

Question

I am looking forward to creating a service using spring boot application where I like to use JDBC prepared statement call which executes the stored procedure get me the required result.
I like to have connection pooling but unfortunately, I don’t know implement
Summary
(services using spring boot --->Simple JDBC with connection pooling---->Mysql)
For this, I have tried to create a data source and execute jdbc statement but not working
#Controller
public class ExampleController {
#Autowired
private ExampleRepository repo;
#RequestMapping("/")
public #ResponseBody String getDataBaseData() throws SQLException{
return repo.getDataBaseData();
}
}
#Configuration
public class DataSources {
#Bean(name = "primary")
#Primary
#ConfigurationProperties(prefix="spring.datasource")
public DataSource primaryDataSource() {
return DataSourceBuilder.create().build();
}
}
#Component
public class ExampleRepository {
#Autowired
private DataSource ds;
public String getDataBaseData() throws SQLException {
Connection con = ds.getConnection();
System.out.println(con);
Statement stmt = con.createStatement();
ResultSet rs = stmt.executeQuery("select * from emp");
while (rs.next())
System.out.println(rs.getInt(1) + " " + rs.getString(2) + " " + rs.getString(3));
con.close();
return rs.toString();
}
}
getting errors like below
com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server.
com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server.
Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaAutoConfiguration.class]: Invocation of init method failed; nested exception is org.hibernate.HibernateException: Access to DialectResolutionInfo cannot be null when 'hibernate.dialect' not set
Expected Result : Database data should display in web browser
This is my github repo https://github.com/PradeepKumarHE/SpringBootWithSimpleJDBC/tree/master
where i have DBscript file to create

Answer 1

What I can see from your pom.xml, you are using spring-boot-starter-data-jpa. It fetches unneccessary dependencies, which triggers SpringBoot jpa autoconfiguration.
If you want to use pure jdbc with spring boot, replace spring-boot-starter-data-jpa with spring-boot-starter-jdbc (https://mvnrepository.com/artifact/org.springframework.boot/)
In this case you need to
have mysql jdbc driver declared in maven dependencies
define spring.datasource.url, spring.datasource.username, spring.datasource.password in your properties or yaml (you don't need to define spring.datasource.driver if you have only one jdbc driver in your maven deps)
remove your DataSources configuration, since springboot will autoconfigure it for you