Spring dblink and invoke trigger on another database - spring

Question

Hi there I would ask you about recommended solutions of connecting another database in Spring + Hibernate.
In my case I have small application with its database and what I need to do is to obtain some data from another (large) db.
Currently I'm doing that with postgresql and dblink but now it would be better to move this query into code.
In near future I'll also need to invoke triggers on that database.
So the question is whats the best practice to solve this kind of connection problems?
To sum up, what I need:
invoke another database trigger
invoke dblink and obtain data from another database

Answer 1

You can try this to invoke another database from your spring boot application. So your base application will use MySQL and the secondary database will be Postgres.
If you are using spring-boot then create lib folder under the project folder (Same hierarchy of src). Add required jdbc jar in that folder.
Then, create DataBaseConfig class with #Configuration, inside that class create ComboPooledDataSource and JdbcTemplate bean.
Now in your service class just do Autowiring of that JdbcTemplate bean. Then, write SQL query to get value using this method queryForList
In pom.xml, you can map that external jar file like below
<dependency>
<groupId>com.mysql</groupId>
<artifactId>db2jcc</artifactId>
<version>11.1</version>
<scope>system</scope>
<systemPath>${project.basedir}/lib/mysql.jar</systemPath>
</dependency>
#Configuration
public class DatabaseConfig {
#Bean(name = "employeeDataBase")
#ConfigurationProperties(prefix = "employee.datasource")
public ComboPooledDataSource employeeDataSource() {
return new ComboPooledDataSource();
}
#Bean(name = "employeeTemplate")
public JdbcTemplate employeeTemplate(#Qualifier("employeeDataBase") DataSource ds) {
return new JdbcTemplate(ds);
}
}
#Service
public class EmployeeService {
#Autowired
#Qualifier("employeeTemplate")
JdbcTemplate employeeTemplate;
public void getEmployeeFromExternalDB() {
List<Map<String, Object>> maps = employeeTemplate.queryForList("SELECT * FROM EMPLOYEE");
}
}
//application.properties
employee.datasource.jdbc-url=${EMPLOYEE_URL}
employee.datasource.user=${EMPLOYEE_UNAME}
employee.datasource.password=${EMPLOYEE_PWD}
employee.datasource.driver-class=com.edb.Driver
employee.datasource.max-idle-time=6
employee.datasource.min-pool-size=3
employee.datasource.max-pool-size=15
employee.datasource.jdbcUrl=${EMPLOYEE_URL}
employee.datasource.driver-class-name=com.edb.Driver