allow to set the config.properties through system property

README.md

@@ -104,7 +104,7 @@ JoularJX can be configured by modifying the ```config.properties``` files:
 - ```vm-power-format```: power format of the shared VM power file. We currently support two formats: ```watts``` (a file containing one float value which is the power consumption of the VM), and ```powerjoular``` (a csv file generated by [PowerJoular](https://github.com/joular/powerjoular) in the host, containing 3 columns: timestamp, CPU utilization of the VM and CPU power of the VM).
 
 You can install the jar package (and the PowerMonitor.exe on Windows) wherever you want, and call it in the ```javaagent``` with the full path.
-However, ```config.properties``` must be copied to the same folder as where you run the Java command.
+However, ```config.properties``` must either be copied to the same folder as where you run the Java command or its location must be set with the ```-Djoularjx.config=/path/to/config.properties``` property when running your program.
 
 In virtual machines, JoularJX requires two steps:
 - Installing a power monitoring tool in the host machine, which will monitor the virtual machine power consumption every second and writing it to a file (to be shared with the guest VM).

src/main/java/org/noureddine/joularjx/utils/AgentProperties.java

@@ -232,7 +232,7 @@ public int loadStackMonitoringSampleRate() {
     }
 
     private Optional<Path> getPropertiesPathIfExists(FileSystem fileSystem) {
-        Path path = fileSystem.getPath("config.properties");
+        Path path = fileSystem.getPath(System.getProperty("joularjx.config", "config.properties"));
 
         if (Files.notExists(path)) {
             logger.log(Level.INFO, "Could not locate config.properties, will use default values");