Efficiently returning the string basis on current datacenter

We have machine hostname as -

dbx111.dc1.host.com
dbx112.dc2.host.com
dcx113.dc3.host.com

dcx115.dev.host.com

Here dc1, dc2, dc3 and dev are our datacenter and we will be having only four datacenter as of now. And also it might be possible that machine hostname can have more dots in between separated by another domain in future.

Now I need to find out which datacenter my current machine is in as I will be running below code on the actual machine.

And also I have two flows as of now: USERFLOW and DEVICEFLOW.

public enum FlowTypeEnum {
    USERFLOW, DEVICEFLOW
}

Problem Statement:

• If my machine is in DC1 and flow type is USERFLOW then I need to return /test/datacenter/dc1 but if flow type is DEVICEFLOW then I need to return /testdevice/datacenter/dc1

• But if my machine is in DC2 and flow type is USERFLOW then I need to return /test/datacenter/dc2 but if flow type is DEVICEFLOW then I need to return /testdevice/datacenter/dc2.

• And if my machine is in DC3 and flow type is USERFLOW then I need to return /test/datacenter/dc3 but if flow type is DEVICEFLOW then I need to return /testdevice/datacenter/dc3.

• But if my machine datacenter is in DEV, and flow type is USERFLOW then I need to return "/test/datacenter/dc1" but if flow type is DEVICEFLOW then I need to return /testdevice/datacenter/dc1.

The only difference between USERFLOW and DEVICEFLOW is - For USERFLOW, I need to use /test and for DEVICEFLOW, I need to use /testdevice and other things are same.

TestingEnum class -

public class TestingDatacenter {

    public static void main(String[] args) {
        String LOCAL_POOK = DatacenterEnum.getOurlocation().toLocalPook(FlowTypeEnum.USERFLOW);
        System.out.println(LOCAL_POOK);
    }
}

DatacenterEnum class -

```
public enum DatacenterEnum {

DEV, DC1, DC2, DC3;

public static DatacenterEnum getOurlocation() {
return ourlocation;

final is meaningless on static methods :

private static final String getHostNameOfServer() {

For the following :

// below if else, looks pretty  odd, may be it can be improved better?
if (f.equals(FlowTypeEnum.DEVICEFLOW)) {
    prefix = "/testdevice";
} else if (f.equals(FlowTypeEnum.USERFLOW)) {
    prefix = "/test";
}

there are 2 alternatives

-
make a getPrefix() method on FlowTypeEnum, reducing the above code to :

prefix = f.getPrefix();

FlowTypeEnum could then look like this :

public enum FlowTypeEnum {
    USERFLOW("/test"), DEVICEFLOW("/testdevice");

    private final String prefix;

    FlowTypeEnum(String prefix) {
        this.prefix = prefix;
    }

    public String getPrefix() {
        return prefix;
    }
}

-
make a map that maps the the FlowTypeEnum instances to a prefix, reducing the above code to :

prefix = mapToPrefix.get(f);

In both cases you might even inline the prefix variable.

Try to make code resistant to likely changes. In this case, server names and paths are likely to change. Pull these from config files.

All these static methods don't seem to be at home on the DatacenterEnum, they don't really operate on DatacenterEnum instances. Perhaps they need to find a home on a new class, where they can be non static.

It is unwise to hard code the data centers as enum instances. It simply won't scale. Renaming, removing or adding data centers in the field will require a new release.

Use more meaningful names for variables :

• dc -> dataCenter

• f -> flowType

Replace this :

currenthost.indexOf(namepart) >= 0

by the more readable :

currenthost.contains(namepart)

StackExchange Code Review Q#55627, answer score: 3