Make Enum.toString() localized

Question

I'm developing an Android application and I want to know if I can set Enum.toString() multilanguage.

I'm going to use this Enum on a Spinner and I want to use multi language texts.

public class Types
{
    public enum Stature
    {
        tall (0, "tall"),
        average(1, "average"),
        small(2, "small");

        private final int stature;
        private final String statureString;

        Stature(int anStature, String anStatureString) { stature = anStature; statureString = anStatureString; }

        public int getValue() { return stature; }

        @Override
        public String toString() { return statureString; }
    }
}

I don't know how to use Context.getString() inside an Enum, and I have hardcoded "tall", "average" and "small" to test it. I have defined that enum inside on a helper class.

This how I use the enum on a Spinner:

mSpinStature.setAdapter(new ArrayAdapter<Stature>(mActivity, android.R.layout.simple_dropdown_item_1line, Stature.values()));

Do you know how can I do it?

Answer 1

Assume this resource path

String resourceBundlePath = "my.package.bundles.messages"

In package my.package.bundles you may have messages.properties, messages_en_US.properties etc.

Then, using

ResourceBundle resourceBundle = ResourceBundle.getBundle(resourceBundlePath);
String messageKey = "myFirstMessage";
String message = resourceBundle.getMessage(messageKey);

message will contain the value of the messageKey property defined on messages.properties. If the current Locale is actually en_US you will get the value from messages_en_US.properties. If the current locale is something you do not have a properties file for the value will be from the default messages.properties

You can also call

ResourceBundle.getBundle(resourceBundlePath, myLocale);

but it is generally better to use the platform locale (have a look at jvm arguments -Duser.language, -Duser.country)

You can have a ResourceBundle for each enum you want to translate with keys the enum element names and use it in the toString() implementation of your enum:

@Override
public String toString() {
return resourceBudle.getString(super.toString());
}

Answer 2

I created a simple library which is a part of my big project (Xdroid):

compile 'com.shamanland:xdroid-enum-format:0.2.4'

Now you can avoid the same monkey-job (declaring field, constructor, etc) for all enumetations by using annotations:

public enum State {
    @EnumString(R.string.state_idle)
    IDLE,

    @EnumString(R.string.state_pending)
    PENDING,

    @EnumString(R.string.state_in_progress)
    IN_PROGRESS,

    @EnumString(R.string.state_cancelled)
    CANCELLED,

    @EnumString(R.string.state_done)
    DONE;
}

And then use the common Java approach - use extensions of class java.text.Format:

public void onStateChanged(State state) {
    EnumFormat enumFormat = EnumFormat.getInstance();
    toast(enumFormat.format(state));
}

strings.xml

<string name="state_idle">Idle</string>
<string name="state_pending">Pending</string>
<string name="state_in_progress">In progress</string>
<string name="state_cancelled">Cancelled</string>
<string name="state_done">Done</string>

Look here how to show Toast simply.

You can also compile a demo app from github.

Answer 3

I would leave enum as is and use the standard ResourceBundle approach http://docs.oracle.com/javase/tutorial/i18n/resbundle/concept.html using Enum.toString as the key