Want a better way to deploy java.util.ResourceBundle properties files with Java application

Question

I am teaching myself Java program localization using java.util.Locale and java.util.ResourceBundle. To this end I wrote a very simple Java app to test English, French and default language message bundles. The program works fine. I am running Eclipse Kepler SR2 on Windows.

My question relates to the deployment of the properties files used by ResourceBundle.getBundle (I will get to my question below) but first a bit about what I have already tried in terms of laying out my demo app and deploying it.

When I first called ResourceBundle.getBundle (see LocaleWrapper.java, below) I discovered the path it searches defaults to the deployment bin folder.

The ResourceBundle Javadoc doesn't talk about deployment folders, nor does the Oracle tutorial on Java internationalization that I was following.

So, to avoid dumping my properties files all in bin, I settled on creating a separate package (demo.locale) for my locale wrapper class and added all of the properties files to that package, as follows:

My Eclipse project named LocaleDemo consists of 5 source files in 2 packages, as follows:

src/demo/DemoApp.java
src/demo.locale/LocaleWrapper.java (wraps java.util.Locale, java.util.ResourceBundle)
src/demo.locale/MessageBundle.properties (default messages, same as English/US)
src/demo.locale/MessageBundle_en_US.properties (English/US messages)
src/demo.locale/MessageBundle_fr_FR.properties (French/France messages)

When the application is deployed it ends up under the bin folder, as follows:

bin/demo/DemoApp.class
bin/demo/locale/LocaleWrapper.class
bin/demo/locale/MessageBundle.properties
bin/demo/locale/MessageBundle_en_US.properties
bin/demo/locale/MessageBundle_fr_FR.properties

(I excluded package info files from these lists for clarity.)

So to get to my actual question:

My concern with this type of deployment is that it mixes properties files with class files.

I tried to separate them by creating a data folder at the same level as my src folder in Ecipse, and I put all the properties files in there, and added the data folder to my build path; however, when I deployed the app all of the properties files simply end up in the bin folder at the top level above the package folders (e.g. bin/MessageBundle.properties).

This was not satisfactory, so I reverted to putting them with the demo.locale package. The layout I settled on was accepted as an answer in this stackoverflow question:

However, I do agree with another poster in that thread who said to separate classes and data, which is what I would prefer, but there was no example given how to do that.

So that is my question: is there a clean way in Eclipse to create a distinct data folder for the application and have the properties files deployed in that folder, not just dumped at the root folder of the project, which is what happened when I tried it.

I am looking for some specific examples of what programmers have done, or even better a reference to some official documentation on this subject -- I could not find anything specifically mentioning how this might be done in practice, only generalities.

As an appendix I have included the source code for my two Java classes below. The resource files I use are straight from the Oracle tutorial that I linked above.

DemoApp.java

package demo;

import demo.locale.LocaleWrapper;

public class DemoApp {

    public static void main(String[] args) {

        LocaleWrapper intl = null;

        // English/USA
        intl = new LocaleWrapper("en", "US");
        doTest(intl);

        // French/France
        intl.changeLocale("fr",  "FR");
        doTest(intl);

        // non-existent language/country will use default
        intl.changeLocale("sp", "MX");
        doTest(intl);

    }

    private static void doTest(LocaleWrapper intl) {
        System.out.println("Testing: " + intl.getLanguage() + "_" + intl.getCountry());
        System.out.println("  " + intl.getString("greetings"));
        System.out.println("  " + intl.getString("farewell"));
        System.out.println("  " + intl.getString("inquiry"));
        System.out.println();
    }
}

LocaleWrapper.java

package demo.locale;

import java.util.Locale;
import java.util.ResourceBundle;

/**
 * Internationalization using java.util.Locale and java.util.ResourceBundle.
 */
public class LocaleWrapper {

    private static final String PATH = "demo/locale/MessageBundle";

    private String language = null;
    private String country = null;
    private Locale locale = null;
    private ResourceBundle messages = null;

    public LocaleWrapper(String language, String country) {
        super();
        this.language = language;
        this.country = country;
        this.locale = new Locale(language, country);
        messages = ResourceBundle.getBundle(PATH, this.locale);
    }

    public void changeLocale(String language, String country) {
        this.language = language;
        this.country = country;
        this.locale = new Locale(language, country);
        messages = ResourceBundle.getBundle(PATH, this.locale);
    }

    /**
     * Get an internationalized string based on it's key.
     * 
     * @param key
     *            Message key.
     * @return Internationalized message string.
     */
    public String getString(String key) {
        return messages.getString(key);
    }

    // getters

    public String getLanguage() {
        return language;
    }

    public String getCountry() {
        return country;
    }

}

Answer 1

Don. You just give a long-long question.

you can specify a resouce folder to palce the resource bundle.

I study question 10911708 And do a example program and it work.

Here is what I did:

Step1: create a resource folder(here,I named it resource) in the same level as src (I use eclipse) folder,and put the properties file in this folder.

Remember to use native2ascii to encode the text to different languange utf8 like:

native2ascii -encoding utf8 MessagesBundle_zh_CN.properties

then you get :

greetings = \u4f60\u597d.(你好)
farewell = \u518d\u89c1.(再见)
inquiry = \u4f60\u597d\u5417?（你好吗?）

save these utf8 text to properties file or you will get messy code.

step2: for two cases:

A. visit resource bundle in jar file (package your project to a runnable jar) In your code,visit the source bundle like:

 Locale currentLocale = new Locale(language, country);

  ResourceBundle messages =
    ResourceBundle.getBundle("resource.MessagesBundle",currentLocale);

  System.out.println(messages.getString("greetings"));
  System.out.println(messages.getString("inquiry"));
  System.out.println(messages.getString("farewell"));

B. visit your resource bundle in eclipse project.

you should click the project properties,and add resource folder in the java build path ,

and then eclipse will automatically copy these files to bin derectory , and you should write the path like:

ResourceBundle messages =
        ResourceBundle.getBundle("MessagesBundle",currentLocale);

without Prefix "resource".

My test result in jar file is:

D:\>java -jar Sample.jar zh CN
你好.
你好吗?
再见.

you can get this demo from: oracle website ,hope it help!