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* Copyright 2010, Red Hat, Inc. and/or its affiliates, and individual contributors
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* http://www.apache.org/licenses/LICENSE-2.0
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.hibernate.validator.messageinterpolation;
import java.util.Locale;
import java.util.MissingResourceException;
import java.util.ResourceBundle;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import javax.validation.MessageInterpolator;
import org.hibernate.validator.internal.engine.messageinterpolation.InterpolationTerm;
import org.hibernate.validator.internal.engine.messageinterpolation.LocalizedMessage;
import org.hibernate.validator.resourceloading.PlatformResourceBundleLocator;
import org.hibernate.validator.spi.resourceloading.ResourceBundleLocator;
/**
* Resource bundle backed message interpolator.
*
* @author Emmanuel Bernard
* @author Hardy Ferentschik
* @author Gunnar Morling
* @author Kevin Pollet <kevin.pollet@serli.com> (C) 2011 SERLI
*/
public class ResourceBundleMessageInterpolator implements MessageInterpolator {
/**
* The name of the default message bundle.
*/
public static final String DEFAULT_VALIDATION_MESSAGES = "org.hibernate.validator.ValidationMessages";
/**
* The name of the user-provided message bundle as defined in the specification.
*/
public static final String USER_VALIDATION_MESSAGES = "ValidationMessages";
/**
* Regular expression used to do locating message parameters.
*/
private static final Pattern MESSAGE_PARAMETER_PATTERN = Pattern.compile( "((\\\\*)\\{[^\\}]+?\\})" );
/**
* Regular expression used to do locating message expressions.
*/
private static final Pattern MESSAGE_EXPRESSION_PATTERN = Pattern.compile( "((\\\\*)\\$?\\{[^\\}]+?\\})" );
/**
* The default locale in the current JVM.
*/
private final Locale defaultLocale;
/**
* Loads user-specified resource bundles.
*/
private final ResourceBundleLocator userResourceBundleLocator;
/**
* Loads built-in resource bundles.
*/
private final ResourceBundleLocator defaultResourceBundleLocator;
/**
* Step 1-3 of message interpolation can be cached. We do this in this map.
*/
private final ConcurrentMap<LocalizedMessage, String> resolvedMessages = new ConcurrentHashMap<LocalizedMessage, String>();
/**
* Flag indicating whether this interpolator should chance some of the interpolation steps.
*/
private final boolean cacheMessages;
public ResourceBundleMessageInterpolator() {
this( null );
}
public ResourceBundleMessageInterpolator(ResourceBundleLocator userResourceBundleLocator) {
this( userResourceBundleLocator, true );
}
public ResourceBundleMessageInterpolator(ResourceBundleLocator userResourceBundleLocator, boolean cacheMessages) {
defaultLocale = Locale.getDefault();
if ( userResourceBundleLocator == null ) {
this.userResourceBundleLocator = new PlatformResourceBundleLocator( USER_VALIDATION_MESSAGES );
}
else {
this.userResourceBundleLocator = userResourceBundleLocator;
}
this.defaultResourceBundleLocator = new PlatformResourceBundleLocator( DEFAULT_VALIDATION_MESSAGES );
this.cacheMessages = cacheMessages;
}
public String interpolate(String message, Context context) {
// probably no need for caching, but it could be done by parameters since the map
// is immutable and uniquely built per Validation definition, the comparison has to be based on == and not equals though
return interpolateMessage( message, context, defaultLocale );
}
public String interpolate(String message, Context context, Locale locale) {
return interpolateMessage( message, context, locale );
}
/**
* Runs the message interpolation according to algorithm specified in the Bean Validation specification.
* <br/>
* Note:
* <br/>
* Look-ups in user bundles is recursive whereas look-ups in default bundle are not!
*
* @param message the message to interpolate
* @param context the context for this interpolation
* @param locale the {@code Locale} to use for the resource bundle.
*
* @return the interpolated message.
*/
private String interpolateMessage(String message, Context context, Locale locale) {
LocalizedMessage localisedMessage = new LocalizedMessage( message, locale );
String resolvedMessage = null;
if ( cacheMessages ) {
resolvedMessage = resolvedMessages.get( localisedMessage );
}
// if the message is not already in the cache we have to run step 1-3 of the message resolution
if ( resolvedMessage == null ) {
ResourceBundle userResourceBundle = userResourceBundleLocator
.getResourceBundle( locale );
ResourceBundle defaultResourceBundle = defaultResourceBundleLocator
.getResourceBundle( locale );
String userBundleResolvedMessage;
resolvedMessage = message;
boolean evaluatedDefaultBundleOnce = false;
do {
// search the user bundle recursive (step1)
userBundleResolvedMessage = interpolateBundleMessage(
resolvedMessage, userResourceBundle, locale, true
);
// exit condition - we have at least tried to validate against the default bundle and there was no
// further replacements
if ( evaluatedDefaultBundleOnce
&& !hasReplacementTakenPlace( userBundleResolvedMessage, resolvedMessage ) ) {
break;
}
// search the default bundle non recursive (step2)
resolvedMessage = interpolateBundleMessage(
userBundleResolvedMessage,
defaultResourceBundle,
locale,
false
);
evaluatedDefaultBundleOnce = true;
} while ( true );
}
// cache resolved message
if ( cacheMessages ) {
String cachedResolvedMessage = resolvedMessages.putIfAbsent( localisedMessage, resolvedMessage );
if ( cachedResolvedMessage != null ) {
resolvedMessage = cachedResolvedMessage;
}
}
// resolve annotation attributes (step 4)
resolvedMessage = interpolateExpression( resolvedMessage, MESSAGE_PARAMETER_PATTERN, context, locale );
// resolve annotation attributes (step 5)
resolvedMessage = interpolateExpression( resolvedMessage, MESSAGE_EXPRESSION_PATTERN, context, locale );
// last but not least we have to take care of escaped literals
resolvedMessage = resolvedMessage.replace( "\\{", "{" );
resolvedMessage = resolvedMessage.replace( "\\}", "}" );
resolvedMessage = resolvedMessage.replace( "\\\\", "\\" );
return resolvedMessage;
}
private boolean hasReplacementTakenPlace(String origMessage, String newMessage) {
return !origMessage.equals( newMessage );
}
private String interpolateBundleMessage(String message, ResourceBundle bundle, Locale locale, boolean recurse) {
Matcher matcher = MESSAGE_PARAMETER_PATTERN.matcher( message );
StringBuffer sb = new StringBuffer();
String resolvedParameterValue;
while ( matcher.find() ) {
String parameter = matcher.group( 1 );
resolvedParameterValue = resolveParameter(
parameter, bundle, locale, recurse
);
matcher.appendReplacement( sb, Matcher.quoteReplacement( resolvedParameterValue ) );
}
matcher.appendTail( sb );
return sb.toString();
}
private String interpolateExpression(String message, Pattern pattern, Context context, Locale locale) {
Matcher matcher = pattern.matcher( message );
StringBuffer sb = new StringBuffer();
while ( matcher.find() ) {
String match = matcher.group( 1 );
InterpolationTerm expression = new InterpolationTerm( match, locale );
if ( expression.needsEvaluation() ) {
String resolvedExpression = expression.interpolate( context );
resolvedExpression = Matcher.quoteReplacement( resolvedExpression );
matcher.appendReplacement( sb, resolvedExpression );
}
}
matcher.appendTail( sb );
return sb.toString();
}
private String resolveParameter(String parameterName, ResourceBundle bundle, Locale locale, boolean recurse) {
String parameterValue;
try {
if ( bundle != null ) {
parameterValue = bundle.getString( removeCurlyBraces( parameterName ) );
if ( recurse ) {
parameterValue = interpolateBundleMessage( parameterValue, bundle, locale, recurse );
}
}
else {
parameterValue = parameterName;
}
}
catch ( MissingResourceException e ) {
// return parameter itself
parameterValue = parameterName;
}
return parameterValue;
}
private String removeCurlyBraces(String parameter) {
return parameter.substring( 1, parameter.length() - 1 );
}
}