I'm building a Java desktop application, using JavaFX, Gradle, javafx-gradle-plugin. This application connects to a server that I also build. When I compile a release version, running gradle jfxNative, I want it to talk to the production server; but otherwise, I want it to talk to localhost.
What's the proper Java/Gradle way of handling this? Some sort of compilation profile?
You can use Gradle's source sets for this:
Sample build.gradle:
apply plugin: 'java'
sourceSets {
prod {
java {
srcDirs = ['src/main/java', 'src/prod/java']
}
}
dev {
java {
srcDirs = ['src/main/java', 'src/dev/java']
}
}
}
task devJar(type: Jar) {
from sourceSets.dev.output
manifest {
attributes("Main-Class": "MyPackage.MyClass")
}
}
task prodJar(type: Jar) {
from sourceSets.prod.output
manifest {
attributes("Main-Class": "MyPackage.MyClass")
}
}
Now you can create two configuration classes for your dev and prod versions:
src/dev/java/MyPackage/Configuration.java
src/prod/java/MyPackage/Configuration.java
All the common code will be in the main source set:
src/main/java/MyPackage/MyClass.java
MyClass can get some values from the configuration class (e.g. Configuration.getBaseUrl())
Running gradle devJar/ gradle prodJar builds one of the variants.
Note: you may need to extend jfxNative/jfxJar instead of Jar in your case.
The simplest solution: Have a configuration file containing such information. You either compile it into the application as a java resource or place it next to the jar file so it can be easily looked up via the filesystem.
With gradle all you need to do is define two build tasks with different input properties and insert the values into your properties file with groovy templating.
application.properties in src/main/resources:
server.address=${serverAddress}
add to your build.gradle
task setProductionServerAddress {
processResources.expand([serverAddress: "https://app.example.com/v1"])
}
jfxJar.dependsOn(setProductionServerAddress)
jfxNative.dependsOn(setProductionServerAddress)
And then on the application:
Properties properties = new Properties();
properties.load(getClass().getResourceAsStream("/application.properties"));
if (properties.getProperty("server.address").equals("${serverAddress}")) {
setUrl("http://localhost:8080/v1");
} else {
setUrl(properties.getProperty("server.address"));
}
Have it check environment variables for names of configuration files. Nothing to do with gradle or build. The same program should run properly wherever it is deployed.
See, e.g., Properties for dev and production
The easiest approach is to define a system property which specifies where the file system location for your data is. The production appserver would define one value (using java -D in the startup script), and your dev app server would define another value. Your application source would consult the system property value (using System.getProperty()) to discover the appropriate location
Also, this makes sense.
Put the information you need in JNDI - that's what it is designed for. Consider letting your application refuse to do anything if the information is not there.
Another reference: What is the best way to manage configuration data
EDIT: Well, what you're asking is logically not possible then, it seems to me. "It should connect to production, unless a specific someone wants to connect to development, but that feature should only be available to unknown persons" The start menu is only a shortcut for running the application, so you can install a "dev" shortcut with command line settings that are read as environment vars.
I would go with the one of the "12 factor app" concept which can be read here
One of its main concept is to use system environment variable which should determine whether you are working on a prod or dev or qa env etc. each project/environment/machine should contain its relevant env property, which after then can be retrieved through the gradle process similar to maven profile plugin.
An example for how to detect:
`if (project.hasProperty('env') && project.getProperty('env') == 'prod') {
apply from: 'gradle/production.gradle'
} else {
apply from: 'gradle/development.gradle'
}`
more on this approach using gradle can be found: gradle profile
You need to pick a configuration scheme (if JavaFX doesn't pick one for you).
I like https://github.com/typesafehub/config .
The config library will have instructions on how to make your "production" config differ from your "development" config.
See also JavaFX:Editable Configuration Files After Packaging
What's the proper Java/Gradle way of handling this? Some sort of compilation profile?
No, I would strongly recommend against compiling different code for production v.s. test. It will invalidate your testing. This should be handled in configuration, not in code. The conventional Java way of doing this is with configuration files (which can be compiled into the JAR as resources).
I've had a bit of a look, and I am surprised not to find a good quality tutorial I can link you to here, sorry (I found a few rubbish ones). Perhaps this question will become a reference for others.
I would do something like this:
My guess as to why there aren't many tutorials for this is that all application or web Frameworks handle this for you.
In my opinion and like others have suggested, this has little to do with the build and more to do with Run Time.
Therefore you could resort to checking for some kind of run time flag - a convenient and often used approach is to use System Properties.
On your Dev box, you could set an Environment variable - lets say FX _DESKTOP_APP_ENV = DEV or some such.
From your code you can look this up and decide the URL you want to use.
String env = System.getenv("FX _DESKTOP_APP_ENV");
String url = env == null ? "Production" : env;
On windows systems you can set up your system environment variables like so -- enter link description here
On *nix systems enter link description here
Hope this helps
