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Anteros Bean Validation for Java.
/*******************************************************************************
* Copyright 2012 Anteros Tecnologia
*
* 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 br.com.anteros.bean.validation;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.MissingResourceException;
import java.util.concurrent.ConcurrentHashMap;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import br.com.anteros.bean.validation.constraints.ELAssert;
import br.com.anteros.bean.validation.messageinterpolation.InterpolationTerm;
import br.com.anteros.bean.validation.messageinterpolation.InterpolationTermType;
import br.com.anteros.bean.validation.messageinterpolation.MessageDescriptorFormatException;
import br.com.anteros.bean.validation.messageinterpolation.MessageInterpolationToken;
import br.com.anteros.bean.validation.messageinterpolation.MessageInterpolationTokenCollector;
import br.com.anteros.bean.validation.messageinterpolation.MessageInterpolationTokenIterator;
import br.com.anteros.bean.validation.resource.messages.AnterosValidationMessages;
import br.com.anteros.core.log.Logger;
import br.com.anteros.core.log.LoggerProvider;
import br.com.anteros.core.resource.messages.AnterosBundle;
import br.com.anteros.core.resource.messages.AnterosResourceBundle;
import br.com.anteros.core.utils.ArrayUtils;
import br.com.anteros.validation.api.MessageInterpolator;
/**
* Description: Resource bundle backed message interpolator. This message resolver resolve message descriptors into
* human-readable messages. It uses ResourceBundles to find the messages. This class is threadsafe.
*/
public class DefaultMessageInterpolator implements MessageInterpolator {
private static final Logger log = LoggerProvider.getInstance().getLogger(DefaultMessageInterpolator.class.getName());
public static final String DEFAULT_VALIDATION_MESSAGES = "ANTEROS_VALIDATION";
public static final String USER_VALIDATION_MESSAGES = "USER_VALIDATION_MESSAGES";
/** Regular expression used to do message interpolation. */
private static final Pattern messageParameterPattern = Pattern.compile("(\\{[\\w\\.]+\\})");
/** The default locale for the current user. */
private Locale defaultLocale;
/** User specified resource bundles hashed against their locale. */
private final Map userBundlesMap = new ConcurrentHashMap();
/** Builtin resource bundles hashed against their locale. */
private final Map defaultBundlesMap = new ConcurrentHashMap();
/**
* Create a new DefaultMessageInterpolator instance.
*/
public DefaultMessageInterpolator() {
this(null);
}
/**
* Create a new DefaultMessageInterpolator instance.
*
* @param resourceBundle
*/
public DefaultMessageInterpolator(AnterosBundle resourceBundle) {
defaultLocale = Locale.getDefault();
if (resourceBundle == null) {
AnterosBundle bundle = AnterosResourceBundle.getBundle(USER_VALIDATION_MESSAGES, defaultLocale);
if (bundle != null) {
userBundlesMap.put(defaultLocale, bundle);
}
} else {
userBundlesMap.put(defaultLocale, resourceBundle);
}
defaultBundlesMap.put(defaultLocale, AnterosResourceBundle.getBundle(DEFAULT_VALIDATION_MESSAGES, defaultLocale, AnterosValidationMessages.class));
}
/** {@inheritDoc} */
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 interpolate(message, context, defaultLocale);
}
/** {@inheritDoc} */
public String interpolate(String message, Context context, Locale locale) {
return interpolateMessage(message, context.getConstraintDescriptor().getAttributes(), locale, context);
}
/**
* Runs the message interpolation according to algorithm specified in JSR 303.
* Note:
* Lookups in user bundles are recursive whereas lookups in default bundle are not!
*
* @param message
* the message to interpolate
* @param annotationParameters
* the parameters of the annotation for which to interpolate this message
* @param locale
* the Locale to use for the resource bundle.
* @return the interpolated message.
*/
private String interpolateMessage(String message, Map annotationParameters, Locale locale, Context context) {
AnterosBundle userResourceBundle = findUserResourceBundle(locale);
AnterosBundle defaultResourceBundle = findDefaultResourceBundle(locale);
String userBundleResolvedMessage;
String resolvedMessage = message;
boolean evaluatedDefaultBundleOnce = false;
do {
// search the user bundle recursive (step1)
userBundleResolvedMessage = replaceVariables(resolvedMessage, userResourceBundle, locale, true);
// exit condition - we have at least tried to validate against the
// default bundle and there were no
// further replacements
if (evaluatedDefaultBundleOnce && !hasReplacementTakenPlace(userBundleResolvedMessage, resolvedMessage)) {
break;
}
// search the default bundle non recursive (step2)
resolvedMessage = replaceVariables(userBundleResolvedMessage, defaultResourceBundle, locale, false);
evaluatedDefaultBundleOnce = true;
} while (true);
// resolve annotation attributes (step 4)
resolvedMessage = replaceAnnotationAttributes(resolvedMessage, annotationParameters);
// resolve custom message parameters (step 5)
if (context instanceof GroupValidationContext) {
GroupValidationContext validationContext = ((GroupValidationContext) context);
resolvedMessage = replaceCustomMessageParameters(resolvedMessage, validationContext.getMessageParameters());
}
if (!(context.getConstraintDescriptor().getAnnotation() instanceof ELAssert)) {
// resolve EL expressions (step 6)
List tokens = null;
MessageInterpolationTokenCollector tokenCollector;
tokenCollector = new MessageInterpolationTokenCollector(resolvedMessage, InterpolationTermType.EL);
tokens = tokenCollector.getTokenList();
resolvedMessage = interpolateExpression(new MessageInterpolationTokenIterator(tokens), context, locale);
}
// curly braces need to be scaped in the original msg, so unescape them
// now
resolvedMessage = resolvedMessage.replace("\\{", "{").replace("\\}", "}").replace("\\\\", "\\");
return resolvedMessage.trim();
}
private String interpolateExpression(MessageInterpolationTokenIterator tokenIterator, Context context, Locale locale)
throws MessageDescriptorFormatException {
while (tokenIterator.hasMoreInterpolationTerms()) {
String term = tokenIterator.nextInterpolationTerm();
String resolvedExpression = interpolate(context, locale, term);
tokenIterator.replaceCurrentInterpolationTerm(resolvedExpression);
}
return tokenIterator.getInterpolatedMessage();
}
public String interpolate(Context context, Locale locale, String term) {
InterpolationTerm expression = new InterpolationTerm(term, locale);
return expression.interpolate(context);
}
private boolean hasReplacementTakenPlace(String origMessage, String newMessage) {
return !origMessage.equals(newMessage);
}
private String replaceVariables(String message, AnterosBundle bundle, Locale locale, boolean recurse) {
Matcher matcher = messageParameterPattern.matcher(message);
StringBuffer sb = new StringBuffer(64);
String resolvedParameterValue;
while (matcher.find()) {
String parameter = matcher.group(1);
resolvedParameterValue = resolveParameter(parameter, bundle, locale, recurse);
matcher.appendReplacement(sb, sanitizeForAppendReplacement(resolvedParameterValue));
}
matcher.appendTail(sb);
return sb.toString();
}
private String replaceAnnotationAttributes(String message, Map annotationParameters) {
Matcher matcher = messageParameterPattern.matcher(message);
StringBuffer sb = new StringBuffer(64);
while (matcher.find()) {
String resolvedParameterValue;
String parameter = matcher.group(1);
Object variable = annotationParameters.get(removeCurlyBrace(parameter));
if (variable != null) {
if (variable.getClass().isArray()) {
resolvedParameterValue = ArrayUtils.toString((Object[]) variable);
} else {
resolvedParameterValue = variable.toString();
}
} else {
resolvedParameterValue = parameter;
}
matcher.appendReplacement(sb, sanitizeForAppendReplacement(resolvedParameterValue));
}
matcher.appendTail(sb);
return sb.toString();
}
private String replaceCustomMessageParameters(String message, Map messageParameters) {
Matcher matcher = messageParameterPattern.matcher(message);
StringBuffer sb = new StringBuffer(64);
while (matcher.find()) {
String resolvedParameterValue;
String parameter = matcher.group(1);
Object variable = messageParameters.get(removeCurlyBrace(parameter));
if (variable != null) {
if (variable.getClass().isArray()) {
resolvedParameterValue = ArrayUtils.toString((Object[]) variable);
} else {
resolvedParameterValue = variable.toString();
}
} else {
resolvedParameterValue = parameter;
}
matcher.appendReplacement(sb, sanitizeForAppendReplacement(resolvedParameterValue));
}
matcher.appendTail(sb);
return sb.toString();
}
private String resolveParameter(String parameterName, AnterosBundle bundle, Locale locale, boolean recurse) {
String parameterValue;
try {
if (bundle != null) {
parameterValue = bundle.getMessage(removeCurlyBrace(parameterName));
if (recurse) {
parameterValue = replaceVariables(parameterValue, bundle, locale, recurse);
}
} else {
parameterValue = parameterName;
}
} catch (MissingResourceException e) {
// return parameter itself
parameterValue = parameterName;
}
return parameterValue;
}
private String removeCurlyBrace(String parameter) {
return parameter.substring(1, parameter.length() - 1);
}
private AnterosBundle findDefaultResourceBundle(Locale locale) {
AnterosBundle bundle = defaultBundlesMap.get(locale);
if (bundle == null) {
bundle = AnterosResourceBundle.getBundle(DEFAULT_VALIDATION_MESSAGES, defaultLocale, AnterosValidationMessages.class);
defaultBundlesMap.put(locale, bundle);
}
return bundle;
}
private AnterosBundle findUserResourceBundle(Locale locale) {
AnterosBundle bundle = userBundlesMap.get(locale);
if (bundle == null) {
bundle = AnterosResourceBundle.getBundle(USER_VALIDATION_MESSAGES, defaultLocale);
if (bundle != null) {
userBundlesMap.put(locale, bundle);
}
}
return bundle;
}
/**
* Set the default locale used by this {@link DefaultMessageInterpolator}.
*
* @param locale
*/
public void setLocale(Locale locale) {
defaultLocale = locale;
}
/**
* Escapes the string to comply with {@link Matcher#appendReplacement(StringBuffer, String)} requirements.
*
* @param src
* The original string.
* @return The sanitized string.
*/
private String sanitizeForAppendReplacement(String src) {
return src.replace("\\", "\\\\").replace("$", "\\$");
}
}
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