I am working on a maven managed Java project. The goal is to read tasks from a JSON file and process them. We also try to keep the whole project modular. Therefore we have a core-project and many modules. The basic idea is, that the core defines the tasks, how to retrieve them ... and the module is performing the task.
I've read a lot about circular dependencies or Dependency Inversion and how to avoid them in theory. However I am unable to put those examples and methods into practice and I am not quite sure if this is my problem. Therefore I was hoping someone kind point me into the right direction. Here's my issue (simplified):
I read "tasks" from a JSON file and convert them into an array using GSON.
[
{
"name": "Do_SOMETHING_1",
"arguments": "myArgs, myArgs_devided_by_comma",
"network": [
{
"start_ip": "192.168.1.1",
"end_ip": "192.168.1.255"
}
]
},
{
"name": "Do_SOMETHING_2",
"arguments": "myArgs, myArgs_devided_by_comma"
}
]
My Task.class looks like this:
public class Task {
private String name;
private String arguments;
private List<network> network;
public String getType() {
return command.toLowerCase();
}
public String[] getArgs() {
String[] args = arguments.split("\\,");
return args;
}
@Override
public String toString() {
return name + " - " + arguments;
}
}
class network {
private String start_ip;
private String end_ip;
@Override
public String toString() {
return start_ip + " - " + end_ip;
}
}
To handle the Tasks I wrote a Jobs class which checks for jobs, builds the array of tasks and then tries to instantiate a new class to process the task depending on what the JSON file specified. It looks like this:
public class Job {
public static Task[] task;
ExecutorService executor = Executors.newFixedThreadPool(25);
public void run() {
try {
fetch_jobs();
} catch (IOException e) {
//Handle e
}
process_jobs();
executor.shutdown();
while (!executor.isTerminated()) {
//Wait until exit
}
}
public void fetch_jobs() throws UnsupportedEncodingException, IOException {
Reader reader = new InputStreamReader(Job.class.getResourceAsStream("/tasks.json"), "UTF-8");
Gson gson = new GsonBuilder().create();
task = gson.fromJson(reader, Task[].class);
}
private void process_jobs() {
for (int i = 0; i < task.length; i++) {
switch(task[i].getType()) {
case "Do_SOMETHING_1":
Runnable worker1 = new Do_SOMETHING_1(task[i]);
executor.execute(worker1);
break;
case "Do_SOMETHING_2":
Runnable worker2 = new Do_SOMETHING_2(task[i]);
executor.execute(worker2);
break;
default:
//Do Nothing
}} }
}
Do_SOMETHING_1 and Do_SOMETHING_2 are maven modules which currently depend on the core so they know what a task is and so I can pass along the task-type-variable (task[i]).
The Problem is that in the core application I need to call Do-SOMETHING_1 and Do_SOMETHING_2. Therefore the core needs to depend on the modules, which is not good I guess. However how could I pass the task along so that Do_SOMETHING_1 can access those information. E.g. Network and arguments... ?
Any help is appreciated since I am really stressed out here.
Hierarchy:
Module(Do_SOMETHING_1) depends on CORE
Module(Do_SOMETHING_2) depends on CORE
CORE depends on Module(Do_SOMETHING_1) <-- WRONG
CORE depends on Module(Do_SOMETHING_2) <-- WRONG
Cheers, Stephanie.
