I would like to find an expedient way to switch between multiple .properties
files for different deployment configurations.
My initial inclination is to create a separate file, selector.properties
, whose single property is used to determine the proper file:
properties.file=deploymentConfiguration1.properties
...for one deployment, or:
properties.file=deploymentConfiguration2.properties
...for the next deployment.
Another developer on my team has an ApplicationProperties
class wherein:
private static final String PROP_FILE="someFileName.properties";
...is the means to do this. However, I want to switch properties files without rebuilding! Thanks in advance for your input.
EDIT: Maybe I should have been more clear initially, but this is for a set of web services packaged as an AAR. I will just drop it into the web server and let Tomcat and Axis2 do their thing.
So, I don't think some of the answers with command-line params will work in this context.
Have multiple property files, one per env, eg;
application-dev.properties
application-test.properties
application-prod.properties
Launch your app with the env as a system property;
java -Denv=test
Load your properties from the relevant file;
String props = "application-" + System.getProperty("env") + ".properties";
Note that I'd generally discourage this in favour of a properties file with a fixed name where the file is generated at build time.
Edit:
If it's a web app, you can set the value of env in the deployment descriptor (web.xml)
<env-entry>
<env-entry-name>myEnv</env-entry-name>
<env-entry-type>java.lang.String</env-entry-type>
<env-entry-value>test</env-entry-value>
</env-entry>
then you can get the value in your web app like this;
Context ctx = new InitialContext();
Context envCtx = (Context) ctx.lookup("java:comp/env");
String env = (String)envCtx.lookup("myEnv");
String props = "application-" + env + ".properties";
Add a argument that points out the configuration file!
java Program -config deploymentConfiguration2.properties
The approach of using a "property manager" property file sounds good.
The master property file could be passed as a parameter to the vm via a jvm argument
But one downside of this process is that the master property file becomes unmanaged over a period of time. For example you may end up retaining some old property file references which no longer makes sense.