Spring + Angular + JAR Build with Command Line Parameter - angularjs

Question

I am building a UI into a JAR for Spring Server. I have a bunch of Angular JS pages. I want to pass in a command line argument to my jar that tells it where the API server is like so:
java -jar application.jar --api=http://ip:9000
So my application.properties file has:
url=${api:http://localhost:9000}
The way I am currently doing is it just having a hardocoded js config file and on each of my .html pages:
<script src="../js/appName/config.angular.js"></script>
Which contains:
var configData = {
url:"http://localhost:9000"
};
And called in each file:
$scope.apiUrl = configData.url;
How do I tap into the applications.properties file that I can override with my JAR command line parameter during runtime vs. the way it has been coded now.

Answer 1

When you pass a value from command line and the same property name is present in properties file then spring boot overrides the value from command line. So to achieve what you want do something like this
In application.properties
#this is default value
app.url=localhost:8080
Create a class to map the properties value or you can use existing class or something else based on your project structure.
#Component
public class Sample {
#Value("${app.url}")
private String url;
public String getUrl() {
return url;
}
public void setUrl(String url) {
this.url = url;
}
}
Now when your execute a jar with argument --app.url="someserver:9090" the value will be overriden and you can use this value anywhere.
Note it will also work if you try to access the properties value directly in jsp using expression.
Try it, it works. I have used the same thing in my latest project which is a composite microservices and each component need each others url.
[Edit]
Reference : http://docs.spring.io/spring-boot/docs/current/reference/html/boot-features-external-config.html

Answer 2

Am I getting it right: The client part is delivered by the application? So the part of the last sentence 'during runtime' has more the meaning of 'bootstrap/initial loading', right? One (old school) approach is to provide the entry html (e.g. index.html) through the application (a simple template engine) and provide the needed information with a setter in a JS config object:
// pseudo js code with thymeleaf
<script th:inline="javascript">
/*<![CDATA[*/
myConfig.url = [[${#httpServletRequest.remoteHost}]];
/*]]>*/
</script>
This is just a sample that will only set the remote host name but I think you get the idea.
Side note: I still don't really get why do you have to set this. If the application contains the client code, why do you work with absolute URLs for remote calls? (Disclaimer: I have only experience in Angular(2) and not with AngularJS)