com.github.fge.msgsimple.bundle.MessageBundle Maven / Gradle / Ivy
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/*
* Copyright (c) 2013, Francis Galiegue
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the Lesser GNU General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* Lesser GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see A bundle is a list of {@link MessageSourceProvider}s. When a message is
* looked up, providers are queried in order for a {@link MessageSource} for
* that locale; if a source is found, it is queried for the message.
*
* When a method is used which does not take a {@link Locale} as an argument,
* the default locale is used (obtained via {@link Locale#getDefault()}). If no
* match is found for the locale, the next, more general locale is tried.
*
* Finally, if no match was found for any provider/source, the key itself is
* returned.
*
* You cannot instantiate this class directly: use {@link #newBuilder()} to
* obtain a builder, then that builder's {@link MessageBundleBuilder#freeze()}
* method to obtain the bundle; alternatively, you can reuse an existing bundle
* and {@link #thaw()} it, modify it and freeze it again.
*
* @see LocaleUtils#getApplicable(Locale)
* @see MessageSourceProvider
*/
@ThreadSafe
public final class MessageBundle
implements Frozen
{
private static final InternalBundle BUNDLE
= InternalBundle.getInstance();
final List providers
= new ArrayList();
/**
* Create a new, empty builder for a bundle
*
* @return a builder
*/
public static MessageBundleBuilder newBuilder()
{
return new MessageBundleBuilder();
}
MessageBundle(final MessageBundleBuilder builder)
{
providers.addAll(builder.providers);
}
/**
* Get a message for the given key and locale
*
* @param locale the locale
* @param key the key
* @return a matching message if found; the key itself if no message is
* found
* @throws NullPointerException either the key or the locale is null
*/
public String getMessage(final Locale locale, final String key)
{
BUNDLE.checkNotNull(key, "query.nullKey");
BUNDLE.checkNotNull(locale, "query.nullLocale");
String ret;
MessageSource source;
for (final Locale l: LocaleUtils.getApplicable(locale))
for (final MessageSourceProvider provider: providers) {
source = provider.getMessageSource(l);
if (source == null)
continue;
ret = source.getKey(key);
if (ret != null)
return ret;
}
// No source found which has the key... Return the key itself.
return key;
}
/**
* Return a message for a given key, using the JVM's current locale
*
* @param key the key
* @return a matching message if found; the key itself if no message is
* found
* @throws NullPointerException key is null
* @see Locale#getDefault()
* @see Locale#setDefault(Locale)
*/
public String getMessage(final String key)
{
return getMessage(Locale.getDefault(), key);
}
/**
* Get a locale-dependent {@code printf()}-like formatted message
*
* This is essentially a call to {@link String#format(Locale, String,
* Object...)}.
*
* There is however one important difference: while {@code
* String.format()} will throw a {@link MissingFormatArgumentException} if
* an argument is missing, this method returns the format itself (or the
* key, like {@link #getMessage(Locale, String)}, if no match was found for
* that locale/key pair).
*
* @param locale the locale
* @param key the key
* @param params the format parameters
* @return the formatted message
*/
public String printf(final Locale locale, final String key,
final Object... params)
{
final String format = getMessage(locale, key);
try {
return String.format(locale, format, params);
} catch (MissingFormatArgumentException ignored) {
return format;
}
}
/**
* Get a {@code printf()}-like message with the default locale
*
* This calls {@link #printf(Locale, String, Object...)} with {@link
* Locale#getDefault()} as the first argument.
*
* @param key the key
* @param params the format parameters
* @return the formatted message
*/
public String printf(final String key, final Object... params)
{
return printf(Locale.getDefault(), key,params);
}
/**
* Check an object reference for {@code null} and return it
*
* If the reference is null, a {@link NullPointerException} is thrown,
* with its message set according to the given locale and key.
*
* @param reference the reference to check
* @param locale the locale to use
* @param key the key to use
* @param type of the reference
* @return the reference
* @throws NullPointerException see description
* @see #getMessage(Locale, String)
*/
public T checkNotNull(final T reference, final Locale locale,
final String key)
{
if (reference == null)
throw new NullPointerException(getMessage(locale, key));
return reference;
}
/**
* Check a reference for {@code null} and return it
*
* This calls {@link #checkNotNull(Object, Locale, String)} with the
* JVM's current locale.
*
* @param reference the reference to check
* @param key the key
* @param type of the reference
* @return the reference
* @throws NullPointerException see description
*/
public T checkNotNull(final T reference, final String key)
{
return checkNotNull(reference, Locale.getDefault(), key);
}
/**
* Check a reference for {@code null} and return it
*
* Like {@link #checkNotNull(Object, Locale, String)}, except that this
* will use {@link #printf(Locale, String, Object...)}
*
* @param reference the reference to check
* @param locale the locale to use
* @param key the key
* @param params arguments for the format string
* @param type of the reference
* @return the reference
* @throws NullPointerException see description
* @see #printf(Locale, String, Object...)
*/
public T checkNotNullPrintf(final T reference, final Locale locale,
final String key, final Object... params)
{
if (reference == null)
throw new NullPointerException(printf(locale, key, params));
return reference;
}
/**
* Check a reference for {@code null} and return it
*
* This calls {@link #checkNotNullPrintf(Object, Locale, String,
* Object...)} with the JVM's current locale.
*
* @param reference the reference
* @param key the key
* @param params arguments for the format string
* @param type of the reference
* @return the reference
* @throws NullPointerException see description
*/
public T checkNotNullPrintf(final T reference, final String key,
final Object... params)
{
return checkNotNullPrintf(reference, Locale.getDefault(), key, params);
}
/**
* Check for a condition
*
* When the condition is false, an {@link IllegalArgumentException} is
* thrown with its message set using the given locale and key.
*
* @param condition the condition to check
* @param locale the locale to use
* @param key the key
* @throws IllegalArgumentException see description
* @see #getMessage(Locale, String)
*/
public void checkArgument(final boolean condition, final Locale locale,
final String key)
{
if (!condition)
throw new IllegalArgumentException(getMessage(locale, key));
}
/**
* Check for a condition
*
* This calls {@link #checkArgument(boolean, Locale, String)} using the
* JVM's current locale.
*
* @param condition the condition to check
* @param key the key
* @throws IllegalArgumentException see description
*/
public void checkArgument(final boolean condition, final String key)
{
checkArgument(condition, Locale.getDefault(), key);
}
/**
* Check for a condition
*
* Like {@link #checkArgument(boolean, Locale, String)}, except that
* {@link #printf(Locale, String, Object...)} is used to fill the message.
*
*
* @param condition the condition to check
* @param locale the locale
* @param key the key
* @param params arguments for the format string
* @throws IllegalArgumentException see description
* @see #printf(Locale, String, Object...)
*/
public void checkArgumentPrintf(final boolean condition,
final Locale locale, final String key, final Object... params)
{
if (!condition)
throw new IllegalArgumentException(printf(locale, key, params));
}
/**
* Check for a condition
*
* This calls {@link #checkArgumentPrintf(boolean, Locale, String,
* Object...)} with the JVM's current locale.
*
* @param condition the condition to check
* @param key the key
* @param params arguments for the format string
* @throws IllegalArgumentException see description
*/
public void checkArgumentPrintf(final boolean condition, final String key,
final Object... params)
{
checkArgumentPrintf(condition, Locale.getDefault(), key, params);
}
@Override
public MessageBundleBuilder thaw()
{
return new MessageBundleBuilder(this);
}
}