Spring data gives us strong support JPA. Spring boot simplified the configuration of Spring Data. The netgloo’s example shows how to access data with only a profile application.properties.
However, some people needs the datasource to be configurable throw external profile but not project inside profile. Ok, we can define a Datasource ourselves to replace the auto generated one by spring boot;

# First Make a default Spring data configuration in profile src/main/resources/application.properties ``` spring.datasource.url = jdbc:postgresql://localhost:5432/bmsc spring.datasource.username = aere spring.datasource.password = aerexu

spring.datasource.testWhileIdle = true
spring.datasource.validationQuery = SELECT 1

spring.jpa.properties.datasource.driver-class-name=org.postgresql.Driver
spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.PostgreSQL9Dialect

# Show or not log for each sql query
spring.jpa.show-sql = true

# Hibernate ddl auto (create, create-drop, update)
spring.jpa.hibernate.ddl-auto = update

# Naming strategy
spring.jpa.hibernate.naming-strategy = org.hibernate.cfg.ImprovedNamingStrategy ```

Second

Make a data source specific configuration profile C:\Users\test\Workplace\config\SpringAll\datasource.properties spring.datasource.url = jdbc:postgresql://192.168.99.100:5432/bmsc spring.datasource.username = aere spring.datasource.password = aerexu

Last

Create an configuration class PersistenceJPAConfig ```java package com.aere.spring.all.config.jpa;

// Imports ...

@Configuration
@ComponentScan
@PropertySource(value = {"classpath:/application.properties",
        "file:/C:\\Users\\test\\Workplace\\config\\SpringAll\\datasource.properties"},
        ignoreResourceNotFound = true)
public class PersistenceJPAConfig {

    @Bean
    @ConfigurationProperties(prefix="spring.datasource")
    public DataSource dataSource() {
        return new DriverManagerDataSource();
    }
} ``` Here we get two profiles, but only one will be counted. If both two exist, the last one counts. If only one exists, of course the exist one count. With such method, we can use the project one for develop and the external one for release. 

That’s all, very simple but need some little tricks.

Plus:

If you want the password in profile showed as encrypted, you can extend the DriverManagerDataSource. java public class EncryptedDriverManagerDataSource extends DriverManagerDataSource{ ... public EncryptedDriverManagerDataSource(String url, String username, String password) { setUrl(url); setUsername(username); String decryptedPass = someDecryptMethod(password); setPassword(decryptedPass); } ... } Then change the DriverManagerDataSource to EncryptedDriverManagerDataSource in PersistenceJPAConfig