Connecting to multiple MySQL db instances using jooq in spring boot application - spring-boot

Question

I have a spring boot application which is using gradle as build tool and jooq for dao class generation and db connection. Previously my application was connecting to single mysql instance. Below are the configuration we used for connecting to single db instance:
spring.datasource.username=user
spring.datasource.password=password
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.name=ds_name
spring.datasource.schema=ds_schema
spring.jooq.sql-dialect=MYSQL
Current project structure is
a) Main application project MainApp having application.properties with above key-value pairs.
b) Separate application project as DBProject which has jooq's generated DAO classes. MainApp include DBProject as a jar.
I am using gradle as build tool for this.
Everything is working fine till here. But now I have to connect to one more instance of MySQL. So, I have created another db project as DBProject2 which also contains dao classes generated by jooq using another mysql schema. I have created DBProject2 exactly as DBProject is created.
Now, my question is if I include both DBProjects in MainApp as jar then both will use same db configuration as in application.properties. How I can make separate db jars to point to their respective db schemas. I googled alot about this but couldn't find helpful solution.

Answer 1

This is what I do to connect to multiple (additional) data sources in my Play app. I am not sure if it is the best approach, but it works great for me. I have changed names below to be generic.
// In my application.conf
// default data source
db.default.driver=com.mysql.jdbc.Driver
db.default.url="jdbc:mysql://localhost:3306/myDb?useSSL=false"
db.default.username=myuser
db.default.password="mypassword"
// additional data source
db.anothersource.driver=com.mysql.jdbc.Driver
db.anothersource.url="jdbc:mysql://localhost:3306/myothersource?useSSL=false"
db.anothersource.username=myuser
db.anothersource.password="mypassword"
// Then in Java, I create a JooqContextProvider class to expose both connections.
public class JooqContextProvider {
#Inject
Database db;
#Inject
play.Configuration config;
public JooqContextProvider(){}
/**
* Creates a default database connection for data access.
* #return DSLConext.
*/
public DSLContext dsl() {
return DSL.using(new JooqConnectionProvider(db), SQLDialect.MYSQL);
}
/**
* Creates an anothersource database connection for data access.
* #return DSLConext for anothersource.
*/
public DSLContext anotherDsl() {
return DSL.using(
new JooqAnotherSourceConnectionProvider(
config.getString("db.anothersource.url"),
config.getString("db.anothersource.username"),
config.getString("db.anothersource.password")),
SQLDialect.MYSQL);
}
}
// Then I needed to implement my JooqAnotherSourceConnectionProvider
public class JooqAnotherSourceConnectionProvider implements ConnectionProvider {
private Connection connection = null;
String url;
String username;
String password;
public JooqAnotherSourceConnectionProvider(String url, String username, String password){
this.url = url;
this.username = username;
this.password = password;
}
#Override
public Connection acquire() throws DataAccessException {
try {
connection = DriverManager.getConnection(url, username, password);
return connection;
}
catch (java.sql.SQLException ex) {
throw new DataAccessException("Error getting connection from data source", ex);
}
}
#Override
public void release(Connection releasedConnection) throws DataAccessException {
if (connection != releasedConnection) {
throw new IllegalArgumentException("Expected " + connection + " but got " + releasedConnection);
}
try {
connection.close();
connection = null;
}
catch (SQLException e) {
throw new DataAccessException("Error closing connection " + connection, e);
}
}
}
// Then in Java code where I need to access one or the other data sources...
jooq.dsl().select().from().where()...
jooq.anotherDsl().select().from().where()...