How to externalize application.properties to an external filesystem location in Spring Boot? - spring

Question

#ComponentScan
#EnableAutoConfiguration
#PropertySource(value = { "file:/Users/Documents/workspace/application.properties" })
public class Application extends SpringBootServletInitializer{
public static void main(String[] args) {
ConfigurableApplicationContext context = SpringApplication.run(Application.class, args);
}
In this case it gives while deploying:
org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [org.springframework.jdbc.core.JdbcTemplate] found for dependency:
Not able to find the correct way to externalize the application properties file
I tried autowiring environment variable which is correctly loaded but then I need to manually define all the beans
#Bean
public JdbcTemplate dataSource() {
String driverClassName = env
.getProperty("spring.datasource.driverClassName");
String dsUrl = env.getProperty("spring.datasource.url");
String username = env.getProperty("spring.datasource.username");
String password = env.getProperty("spring.datasource.password");
//DataSource dataSource = new SimpleDriverDataSource(new driverClassName, dsUrl, username, password);
JdbcTemplate jdbc = new JdbcTemplate(dataSource);
return jdbc;
}
This deploys without throwing error but not responding.

Answer 1

If you're deploying a WAR to Tomcat, then you need to define a context XML as described here: https://tomcat.apache.org/tomcat-7.0-doc/config/context.html#Defining_a_context
For example, you would typically define $CATALINA_BASE/conf/Catalina/localhost/my-app.xml if you have http://localhost:8080/my-app/.
The file would then look like this:
<Context docBase='path/to/my-app/my-app.war'>
<Environment name='app_config_dir' value='path/to/my-app/' type='java.lang.String'/>
</Context>
In your code, implement ApplicationContextAware and override setApplicationContext. Here is an example:
public class Setup implements ApplicationContextAware {
#Override
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
log.info("Set application context. App Config Property: {}",applicationContext.getEnvironment().getProperty("app_config_dir"));
}
}
You can now load the properties file from app_config_dir.

Answer 2

There is no need to define it by using #PropertySource annotation. You should just use spring.config.location property to set your application.properties location. That property can be set up for example in command line:
java -jar myapp.jar --spring.config.location=/Users/Documents/workspace/

Answer 3

You can define an environment variable called SPRING_CONFIG_LOCATION and give it a value that can be a folder (which should end in /) or a file. In any case the location should pe prefixed with file::
SPRING_CONFIG_LOCATION = file:C:/workspace/application.properties
or
SPRING_CONFIG_LOCATION = file:C:/workspace/
More about this here.

Answer 4

You can use #PropertySource too because it is useful when you are deploying application as war file to tomcat.
#PropertySource is not working because you are missing #Configuration annotation. As per the Spring-Boot documentation, #PropertySource annotations should be present on your #Configuration classes.
Following works
#Configuration
#ComponentScan
#EnableAutoConfiguration
#PropertySource(value = { "file:/Users/Documents/workspace/application.properties" })
public class Application extends SpringBootServletInitializer{
public static void main(String[] args) {
ConfigurableApplicationContext context = SpringApplication.run(Application.class, args);
}
You can also load multiple properties file. For ex:
#PropertySource(value = {"classpath:application.properties", "file:/Users/overriding.propertis"}, ignoreResourceNotFound = true)
Note that the order of the declared files is important. If the same key is defined in two or more files, the value associated with the key in the last declared file will override any previous value(s).