Spring boot external application.properties

Question

I am developing a spring boot application

I want to override some properties in src/main/resources/application.properties with an external file (e.g. /etc/projectName/application.properties).

I tried several methods:

1. @PropertySource("file:/etc/projectName/application.properties") as annotation at ApplicationConfig.java

2. spring.config.location=/etc/projectName/application.properties in my application.properties in resources

I tested it with spring.port. The first method only added properties but didn't override them.

Answer 1

I always use --spring.config.location= in the command line as specified in the documentation, and you can put various files in this, one with default values and another with the overridden ones.

Edit:
Alternatively, you could also use something like :

@PropertySources({
    @PropertySource("classpath:default.properties")
    , @PropertySource(value = "file:${external.config}", ignoreResourceNotFound = true)
})

and specify a external.config in your application.properties.
This would provide a default path for overridding config, that is still overriddable itself by specifying a --external.config in the command line.
I use this with ${external.config} being defined as a system env variable, but it should work with a application.properties variable too.

Answer 2

I had the same requirement like yours( war package instead of a fat jar) and I manged to externalize the configuration file: In my main class I made this configuration:

@SpringBootApplication
@PropertySource("file:D:\\Projets\\XXXXX\\Config\\application.properties")
public class WyApplication extends SpringBootServletInitializer {

    public static void main(String[] args) {
        SpringApplication.run(WyApplication.class, args);
    }

}   

Hope this will help you. Good luck.

Answer 3

Notes

1) Tomcat allows you to define context parameters 2) Spring Boot will read the properties defined in Tomcat context parameters as if you are defining them as -Dsomething=some_value

Options

Option 1: Hence a possible way is for you to define spring.config.location at the Tomcat context paramter:

<Context>
    <Parameter name="spring.config.location" value="/path/to/application.properties" />
</Context>

Option 2: define a system property at the Tomcat's setenv.sh file

Dspring.config.location=/path/to/application.properties

Option 3: define an environment variable: SPRING_CONFIG_LOCATION

Answer 4

If you do not want to use any solution from above, you could do the following in the start of your main(String args[]) method (before the usage of SpringApplication.run(MyClass.class, args):

//Specifies a custom location for application.properties file.
System.setProperty("spring.config.location", "target/config/application.properties");

Answer 5

Note: The following solution will replace the old application.properties entirely

You can place your application.properties in one of the following locations:

• Under /config sub-directory of the current directory
• The current directory
• A classpath /config package
• The classpath root

And then exclude the default one under resources directory, like:

<build>
    <resources>
        <resource>
            <directory>src/main/resources</directory>
            <filtering>true</filtering>
            <excludes>
                <exclude>**/application.properties</exclude>
            </excludes>
        </resource>
    </resources>
</build>

Find more details in this link

Answer 6

Based on @JR Utily response this "format" work for me when use email config and multiple properties (I tried to use a PropertySourcesPlaceholderConfigurer Bean but for any reason don't take the email config):

@SpringBootApplication
@PropertySources({
    @PropertySource("classpath:application.properties"),
    @PropertySource(value = "file:/path/to/config1.properties", ignoreResourceNotFound = true),
    @PropertySource(value = "file:/path/to/config2.properties", ignoreResourceNotFound = true),
    @PropertySource(value = "file:/path/to/config3.properties", ignoreResourceNotFound = true)
})
public class ExampleApplication {

    public static void main(String[] args) {
        SpringApplication.run(ExampleApplication.class, args);
    }
}

Answer 7

Yes we can add application.properties file from external folder. The simplest way is

@SpringBootApplication
public class ExternalAppPropertiesTest{

    public static void main(String[] args) {
        System.setProperties("spring.config.location","D:\\yourfoldername where application.properties added");
        SpringApplication.run(ExternalAppPropertiesTest.class, args);
    }
}

N.B. - In case of externally application.properties access please don't use @PropertySources annotation and file path. It will not access your logging properties e.g. logging.file.name=yourlogfilename.log

Here is one more suggestion, for code maintenance you can put your applcation.properties by renaming the file name in your src folder of spring boot application and maintain the changes which is done in external file.