I am trying to build out Integration Tests (IT) for an application. The application has at its centre a Server, written in Java, that set-ups a message queue from which it polls for messages sent to it on a particular port-number. I would like to write an Integration Test which fires some messages at this server/port-number and tests the response.
Below is the full list of VM arguments that I run when I start the server from within Intellij manually. I can start the server this way and then fire my test messages at it but I would like to convert this into IT tests so that I can start/stop the server programmatically at the start and end of my tests.
The problem I am having is that I dont know how to start the server application from within my test class. So to ask it more plainly, how to start the Java main() of a class in its own process thread. I am working within Intellij (2019.1) and Java 8. Should I be using the ProcessBuilder or ExecutorService maybe ?
I think I can use System.setProperty for some of the VM arguments but not sure how to specify the -XX ones...so that would be a second part to this question.
-Djava.endorsed.dirs=/Users/xxx/dev/src/repo/xxx/myapp/target/classes/lib/endorsed
-Dmyapp.home=/private/var/tmp/myapp
-Dmyapp.log.dir=/private/var/tmp
-Dmyapp.env=/Users/xxx/dev/src/repo/xxx/myapp/target/classes/etc/examples/environment-apa.sh
-Dsimplelogger.properties=/private/var/tmp/myapp/etc/simplelogger.properties
-server
-XX:CompileThreshold=2500
-XX:+UseFastAccessorMethods
-Xss256k
-Xmx1g
-Xms512m
I've tried implementing this using the ExecutorService
public class ServerTest {
@Test
public void shouldStartServerOk() {
try{
startServer();
}catch(Exception e){
e.printStackTrace();
fail();
}
}
private void startServer(){
ExecutorService executor = Executors.newFixedThreadPool(1);
Runnable runnableTask = new Runnable() {
@Override
public void run() {
String [] args = new String[0];
try {
System.setProperty("java.endorsed.dirs", "/Users/xxx/dev/src/gitlab/xxx/myapp/target/classes/lib/endorsed");
System.setProperty("myapp.home", "/private/var/tmp/myapp");
System.setProperty("myapp.log.dir", "/private/var/tmp");
System.setProperty("myapp.env", "/Users/xxx/dev/src/gitlab/xxx/myapp/target/classes/etc/examples/environment-apa.sh");
System.setProperty("simplelogger.properties", "/private/var/tmp/myapp/etc/simplelogger.properties");
System.setProperty("-server", "TRUE");
MyApp.main(args);
} catch (Exception e) {
e.printStackTrace();
}
}
};
executor.execute(runnableTask);
// shut down the executor manually
//executor.shutdown();
}
But this doesn't seem to work although the test does complete green. When I debug the process, the flow doesn't Step-Into MyApp.main(args). Strangely when I just try running MyApp.main(args) on its own outside of the ExecutorService then it starts and runs fine until I hit Stop in my IDE. This is behaviour I would like just the additional ability to Start/Stop the process.
UPDATE-1: following the comments from @dmitrievanthony and @RealSkeptic I have tried to implement something along those lines based on SO question, Executing a Java application in a separate process/636367,
public final class JavaProcess {
private JavaProcess() {}
public static int exec(Class klass) throws IOException,
InterruptedException {
String javaHome = System.getProperty("java.home");
String javaBin = javaHome +
File.separator + "bin" +
File.separator + "java";
String classpath = System.getProperty("java.class.path");
String className = klass.getName();
ProcessBuilder processBuilder = new ProcessBuilder(
javaBin,
"-cp",
classpath,
className
);
Map<String, String> env = processBuilder.environment();
env.put("java.endorsed.dirs", "/Users/xxx/dev/src/gitlab/xxx/myapp/target/classes/lib/endorsed");
env.put("myapp.home", "/private/var/tmp/myapp");
env.put("myapp.log.dir", "/private/var/tmp");
env.put("myapp.env", "/Users/xxx/dev/src/gitlab/xxx/myapp/target/classes/etc/examples/environment-apa.sh");
env.put("simplelogger.properties", "/private/var/tmp/myapp/etc/simplelogger.properties");
env.put("-XX:CompileThreshold", "2500");
env.put("-XX:+UseFastAccessorMethods", "");
env.put("-Xss256k", "");
env.put("-Xmx1g", "");
env.put("-Xms512m", "");
Process process = processBuilder.inheritIO().start();
process.waitFor();
return process.exitValue();
}
and calling it in my myAppIT test class as int status = JavaProcess.exec(MyAapp.class);
I can now see my class "MyApp" starting - and can confirm that the process flow is running into my MyApp.main() class. The problem now is that the System.env variables that I am setting in my ProcessBuilder do not appear to be available in the called programme ie. when I print to log System.getProperty("myapp.home") its returning null even though I can confirm that it is being set as shown in the code - does anyone have any ideas on this one please ?
UPDATE-2: I am trying to implement suggestion by @RealSkeptic and passing in the arguments in a similar way as passing commandline arguments as shown in the code snippet below. Now I am getting an exception
Error: Could not find or load main class xxx.xxx.xxx.xxx.MyApp -Djava.endorsed.dirs=.Users.xxx.dev.src.gitlab.myapp.myapp.target.classes.lib.endorsed
one problem I see is that the forward slashes of the path have been translated to ".". The path should read, Djava.endorsed.dirs=/Users/xxx/dev/src/gitlab/myapp/myapp/target/classes/lib/endorsed
ProcessBuilder processBuilder = new ProcessBuilder(
javaBin,
"-cp",
classpath,
className + " " +
"-Djava.endorsed.dirs=" + "/Users/xxx/dev/src/gitlab/xxx/myapp/target/classes/lib/endorsed " +
"-Dmyapp.home=/private/var/tmp/myapp " +
"-Dmyapp.log.dir=/private/var/tmp" +
"-Dmyapp.env=/Users/xxx/dev/src/gitlab/xxx/myapp/target/classes/etc/examples/environment-apa.sh " +
"-Dsimplelogger.properties=/private/var/tmp/myapp/etc/simplelogger.properties " +
"-server " +
"-XX:CompileThreshold=2500 " +
"-XX:+UseFastAccessorMethods " +
"-Xss256k " +
"-Xmx1g " +
"-Xms512m"
);
Update-3 following the last comment from @RealSkeptic I've modified my code (see below) and this now works.
ProcessBuilder processBuilder = new ProcessBuilder(
javaBin,
"-cp",
classpath,
"-Djava.endorsed.dirs=" + "/Users/xxx/dev/src/gitlab/xxx/myapp/target/classes/lib/endorsed",
"-Dmyapp.home=/private/var/tmp/myapp",
"-Dmyapp.log.dir=/private/var/tmp",
"-Dmyapp.env=/Users/xxx/dev/src/gitlab/xxx/myapp/target/classes/etc/examples/environment-apa.sh",
"-Dsimplelogger.properties=/private/var/tmp/myapp/etc/simplelogger.properties ",
"-server",
"-XX:CompileThreshold=2500",
"-XX:+UseFastAccessorMethods",
"-Xss256k",
"-Xmx1g",
"-Xms512m",
className
);
