/*
* Copyright (C) 2010, Sasa Zivkov <sasa.zivkov@sap.com>
* and other copyright owners as documented in the project's IP log.
*
* This program and the accompanying materials are made available
* under the terms of the Eclipse Distribution License v1.0 which
* accompanies this distribution, is reproduced below, and is
* available at http://www.eclipse.org/org/documents/edl-v10.php
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
*
* - Neither the name of the Eclipse Foundation, Inc. nor the
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*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
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package org.eclipse.jgit.nls;
import java.lang.reflect.Field;
import java.util.Locale;
import java.util.MissingResourceException;
import java.util.ResourceBundle;
import org.eclipse.jgit.errors.TranslationBundleLoadingException;
import org.eclipse.jgit.errors.TranslationStringMissingException;
/**
* Base class for all translation bundles that provides injection of translated
* texts into public String fields.
*
* <p>
* The usage pattern is shown with the following example. First define a new
* translation bundle:
*
* <pre>
* public class TransportText extends TranslationBundle {
* public static TransportText get() {
* return NLS.getBundleFor(TransportText.class);
* }
*
* public String repositoryNotFound;
*
* public String transportError;
* }
* </pre>
*
* Second, define one or more resource bundle property files.
*
* <pre>
* TransportText_en_US.properties:
* repositoryNotFound=repository {0} not found
* transportError=unknown error talking to {0}
* TransportText_de.properties:
* repositoryNotFound=repository {0} nicht gefunden
* transportError=unbekannter Fehler während der Kommunikation mit {0}
* ...
* </pre>
*
* Then make use of it:
*
* <pre>
* NLS.setLocale(Locale.GERMAN); // or skip this call to stick to the JVM default locale
* ...
* throw new TransportException(uri, TransportText.get().transportError);
* </pre>
*
* The translated text is automatically injected into the public String fields
* according to the locale set with {@link NLS#setLocale(Locale)}. However, the
* {@link NLS#setLocale(Locale)} method defines only prefered locale which will
* be honored only if it is supported by the provided resource bundle property
* files. Basically, this class will use
* {@link ResourceBundle#getBundle(String, Locale)} method to load a resource
* bundle. See the documentation of this method for a detailed explanation of
* resource bundle loading strategy. After a bundle is created the
* {@link #effectiveLocale()} method can be used to determine whether the bundle
* really corresponds to the requested locale or is a fallback.
*
* <p>
* To load a String from a resource bundle property file this class uses the
* {@link ResourceBundle#getString(String)}. This method can throw the
* {@link MissingResourceException} and this class is not making any effort to
* catch and/or translate this exception.
*
* <p>
* To define a concrete translation bundle one has to:
* <ul>
* <li>extend this class
* <li>define a public static get() method like in the example above
* <li>define public static String fields for each text message
* <li>make sure the translation bundle class provide public no arg constructor
* <li>provide one or more resource bundle property files in the same package
* where the translation bundle class resides
* </ul>
*/
public abstract class TranslationBundle {
private Locale effectiveLocale;
private ResourceBundle resourceBundle;
/**
* @return the locale locale used for loading the resource bundle from which
* the field values were taken
*/
public Locale effectiveLocale() {
return effectiveLocale;
}
/**
* @return the resource bundle on which this translation bundle is based
*/
public ResourceBundle resourceBundle() {
return resourceBundle;
}
/**
* Injects locale specific text in all instance fields of this instance.
* Only public instance fields of type <code>String</code> are considered.
* <p>
* The name of this (sub)class plus the given <code>locale</code> parameter
* define the resource bundle to be loaded. In other words the
* <code>this.getClass().getName()</code> is used as the
* <code>baseName</code> parameter in the
* {@link ResourceBundle#getBundle(String, Locale)} parameter to load the
* resource bundle.
* <p>
*
* @param locale
* defines the locale to be used when loading the resource bundle
* @exception TranslationBundleLoadingException
* see {@link TranslationBundleLoadingException}
* @exception TranslationStringMissingException
* see {@link TranslationStringMissingException}
*/
void load(Locale locale)
throws TranslationBundleLoadingException {
Class bundleClass = getClass();
try {
resourceBundle = ResourceBundle.getBundle(bundleClass.getName(),
locale, bundleClass.getClassLoader());
} catch (MissingResourceException e) {
throw new TranslationBundleLoadingException(bundleClass, locale, e);
}
this.effectiveLocale = resourceBundle.getLocale();
for (Field field : bundleClass.getFields()) {
if (field.getType().equals(String.class)) {
try {
String translatedText = resourceBundle.getString(field.getName());
field.set(this, translatedText);
} catch (MissingResourceException e) {
throw new TranslationStringMissingException(bundleClass, locale, field.getName(), e);
} catch (IllegalArgumentException e) {
throw new Error(e);
} catch (IllegalAccessException e) {
throw new Error(e);
}
}
}
}
}