Refactoring code into function by mapping

Question

I have following code:

...
if (...) { // Handling emails
  int emailType = -1; 
  if (types != null) {
    String type = foo(types);
    if (type.equals("work")) {
      emailType = Email.TYPE_WORK;  // android.provider.ContactsContract.CommonDataKinds.Email
    } else if (type.equals("home")) {
      veemailType = Email.TYPE_HOME;
    } else if (type.equals("mobile")) {
      emailType = Email.TYPE_MOBILE;
    } else if (type.equals("other")) {
      emailType = Email.TYPE_OTHER;
    }
    bar(emailType);
  }
} else if (...) { // Handling phones
  int telType = -1; 
  if (types != null) {
    String type = foo(types);
    if (type.equals("work")) {
      telType = Phone.TYPE_WORK;  // android.provider.ContactsContract.CommonDataKinds.Phone
    } else if (type.equals("home")) {
      telType = Phone.TYPE_HOME;
    } else if (type.equals("mobile")) {
      telType = Phone.TYPE_MOBILE;
    } else if (type.equals("other")) {
      telType = Phone.TYPE_OTHER;
    }
    bar(telType);
  }
} else if ...

Apparently I should use a function to wrap these similar handling logic, but no idea how to do it.

With C/C++ I would prefer macro in this case, but looks like there is no macro in Java?

Answer 1

You need to write methods for handlingPhones and Handling emails. Instead of using the if else loops you should you switch case statements. I would recomment installing various code quality plugins which will point out your code quality issues as and when you are writing your java code

Answer 2

One opition here is to get rid of int constants and introduce enum class with a factory method to produce values from strings:

public enum Email{
    TYPE_HOME("home"),
    TYPE_MOBILE("mobile"),
    TYPE_OTHER("other"),
    TYPE_WORK("work");

    private final String stringValue;

    Email(String stringValue) {
        this.stringValue = stringValue;
    }

    public static Email parse(String value){
        for (Email email : values()){
            if (email.stringValue.equals(value)){
                return email;
            }
        }
        throw new IllegalArgumentException("Illegal argument: " + value);
    }
}

Now you can replace if-else chain with the following:

String types = foo(types);
Email email = Email.parse(types);
bar(email);

Answer 3

You should create a HashMap from the string version of the email type to the Email.TYPE_*.

Then you can pass off the map to a function, eg

int clean(Map<String, Integer> typemap, String type_s) {
    return bar(typemap.get(foo(type_s)));
}