How to use 2 or more databases with spring?

Question

I have an application that runs Spring MVC.

I need it to access 2 different databases in my app (one is a PostgreSQL and the other one is a MySQL database).

How do I configure this using just annotations or application.properties file?

Regards.

Answer 1

Here is the example code for having multiple Database/datasource on Spring-Boot I hope it helps!

application.properties

spring.ds_items.driverClassName=org.postgresql.Driver 
spring.ds_items.url=jdbc:postgresql://srv0/test 
spring.ds_items.username=test0 
spring.ds_items.password=test0 


spring.ds_users.driverClassName=org.postgresql.Driver 
spring.ds_users.url=jdbc:postgresql://srv1/test 
spring.ds_users.username=test1 
spring.ds_users.password=test1 

DatabaseItemsConfig.java

package sb; 

import org.springframework.boot.autoconfigure.jdbc.TomcatDataSourceConfiguration; 
import org.springframework.boot.context.properties.ConfigurationProperties; 
import org.springframework.context.annotation.Bean; 
import org.springframework.context.annotation.Configuration; 
import org.springframework.jdbc.core.JdbcTemplate; 

import javax.sql.DataSource; 

@Configuration 
@ConfigurationProperties(name = "spring.ds_items") 
public class DatabaseItemsConfig extends TomcatDataSourceConfiguration { 

    @Bean(name = "dsItems") 
    public DataSource dataSource() { 
        return super.dataSource(); 
    } 

    @Bean(name = "jdbcItems") 
    public JdbcTemplate jdbcTemplate(DataSource dsItems) { 
        return new JdbcTemplate(dsItems); 
    } 
} 

DatabaseUsersConfig.java

package sb; 

import org.springframework.boot.autoconfigure.jdbc.TomcatDataSourceConfiguration; 
import org.springframework.boot.context.properties.ConfigurationProperties; 
import org.springframework.context.annotation.Bean; 
import org.springframework.context.annotation.Configuration; 
import org.springframework.jdbc.core.JdbcTemplate; 

import javax.sql.DataSource; 

@Configuration 
@ConfigurationProperties(name = "spring.ds_users") 
public class DatabaseUsersConfig extends TomcatDataSourceConfiguration { 

    @Bean(name = "dsUsers") 
    public DataSource dataSource() { 
        return super.dataSource(); 
    } 

    @Bean(name = "jdbcUsers") 
    public JdbcTemplate jdbcTemplate(DataSource dsUsers) { 
        return new JdbcTemplate(dsUsers); 
    } 

} 

ItemRepository.java

package sb; 

import org.slf4j.Logger; 
import org.slf4j.LoggerFactory; 
import org.springframework.beans.factory.annotation.Autowired; 
import org.springframework.beans.factory.annotation.Qualifier; 
import org.springframework.jdbc.core.JdbcTemplate; 
import org.springframework.jdbc.core.RowMapper; 
import org.springframework.stereotype.Repository; 

import java.sql.ResultSet; 
import java.sql.SQLException; 

@Repository 
public class ItemRepository { 
    protected final Logger log = LoggerFactory.getLogger(getClass()); 

    @Autowired 
    @Qualifier("jdbcItems") 
    protected JdbcTemplate jdbc; 

    public Item getItem(long id) { 
        return jdbc.queryForObject("SELECT * FROM sb_item WHERE id=?", itemMapper, id); 
    } 

    private static final RowMapper<Item> itemMapper = new RowMapper<Item>() {
        public Item mapRow(ResultSet rs, int rowNum) throws SQLException { 
            Item item = new Item(rs.getLong("id"), rs.getString("title")); 
            item.price = rs.getDouble("id"); 
            return item; 
        } 
    }; 
} 

UserRepository.java

package sb; 

import org.slf4j.Logger; 
import org.slf4j.LoggerFactory; 
import org.springframework.beans.factory.annotation.Autowired; 
import org.springframework.beans.factory.annotation.Qualifier; 
import org.springframework.jdbc.core.JdbcTemplate; 
import org.springframework.jdbc.core.RowMapper; 
import org.springframework.stereotype.Repository; 

import java.sql.ResultSet; 
import java.sql.SQLException; 

@Repository 
public class UserRepository { 
    protected final Logger log = LoggerFactory.getLogger(getClass()); 

    @Autowired 
    @Qualifier("jdbcUsers") 
    protected JdbcTemplate jdbc; 

    public User getUser(long id) { 
        return jdbc.queryForObject("SELECT * FROM sb_user WHERE id=?", userMapper, id); 
    } 

    private static final RowMapper<User> userMapper = new RowMapper<User>() {
        public User mapRow(ResultSet rs, int rowNum) throws SQLException { 
            User user = new User(rs.getLong("id"), rs.getString("name")); 
            user.alias = rs.getString("alias"); 
            return user; 
        } 
    }; 
} 

Controller.java

package sb; 

import org.slf4j.Logger; 
import org.slf4j.LoggerFactory; 
import org.springframework.beans.factory.annotation.Autowired; 
import org.springframework.web.bind.annotation.RequestMapping; 
import org.springframework.web.bind.annotation.RequestParam; 
import org.springframework.web.bind.annotation.RestController; 

@RestController 
public class Controller { 
    protected final Logger log = LoggerFactory.getLogger(getClass()); 

    @Autowired 
    private UserRepository users; 

    @Autowired 
    private ItemRepository items; 

    @RequestMapping("test") 
    public String test() { 
        log.info("Test"); 
        return "OK"; 
    } 

    @RequestMapping("user") 
    public User getUser(@RequestParam("id") long id) { 
        log.info("Get user"); 
        return users.getUser(id); 
    } 

    @RequestMapping("item") 
    public Item getItem(@RequestParam("id") long id) { 
        log.info("Get item"); 
        return items.getItem(id); 
    } 

} 

Application.java

package sb; 

import org.springframework.boot.SpringApplication; 
import org.springframework.boot.autoconfigure.EnableAutoConfiguration; 
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration; 
import org.springframework.context.annotation.ComponentScan; 
import org.springframework.context.annotation.Configuration; 

@EnableAutoConfiguration(exclude = DataSourceAutoConfiguration.class) 
@Configuration 
@ComponentScan(basePackages = "sb") 
public class Application { 

    public static void main(String[] args) throws Throwable { 
        SpringApplication app = new SpringApplication(Application.class); 
        app.run(); 
    } 
}