/*
* Copyright 2014 Attila Szegedi, Daniel Dekany, Jonathan Revusky
*
* 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 freemarker.core;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Locale;
import java.util.StringTokenizer;
import java.util.TimeZone;
import java.util.concurrent.ConcurrentHashMap;
import freemarker.log.Logger;
import freemarker.template.TemplateDateModel;
import freemarker.template.TemplateModelException;
class JavaTemplateDateFormatFactory extends TemplateDateFormatFactory {
static final JavaTemplateDateFormatFactory INSTANCE = new JavaTemplateDateFormatFactory();
private static final Logger LOG = Logger.getLogger("freemarker.runtime");
private static final ConcurrentHashMap<CacheKey, DateFormat> GLOBAL_FORMAT_CACHE
= new ConcurrentHashMap<CacheKey, DateFormat>();
private static final int LEAK_ALERT_NUMBER_FORMAT_CACHE_SIZE = 1024;
private JavaTemplateDateFormatFactory() {
// Can't be instantiated
}
/**
* @param zonelessInput
* Has no effect in this implementation.
*/
@Override
public TemplateDateFormat get(int dateType, boolean zonelessInput, String params, Locale locale, TimeZone timeZone,
Environment env) throws TemplateModelException, UnknownDateTypeFormattingUnsupportedException,
InvalidFormatParametersException {
return new JavaTemplateDateFormat(getJavaDateFormat(dateType, params, locale, timeZone));
}
/**
* Returns a "private" copy (not in the global cache) for the given format.
*/
private DateFormat getJavaDateFormat(int dateType, String nameOrPattern, Locale locale, TimeZone timeZone)
throws UnknownDateTypeFormattingUnsupportedException, InvalidFormatParametersException {
// Get DateFormat from global cache:
CacheKey cacheKey = new CacheKey(dateType, nameOrPattern, locale, timeZone);
DateFormat jFormat;
jFormat = GLOBAL_FORMAT_CACHE.get(cacheKey);
if (jFormat == null) {
// Add format to global format cache.
StringTokenizer tok = new StringTokenizer(nameOrPattern, "_");
int tok1Style = tok.hasMoreTokens() ? parseDateStyleToken(tok.nextToken()) : DateFormat.DEFAULT;
if (tok1Style != -1) {
switch (dateType) {
case TemplateDateModel.UNKNOWN: {
throw new UnknownDateTypeFormattingUnsupportedException();
}
case TemplateDateModel.TIME: {
jFormat = DateFormat.getTimeInstance(tok1Style, cacheKey.locale);
break;
}
case TemplateDateModel.DATE: {
jFormat = DateFormat.getDateInstance(tok1Style, cacheKey.locale);
break;
}
case TemplateDateModel.DATETIME: {
int tok2Style = tok.hasMoreTokens() ? parseDateStyleToken(tok.nextToken()) : tok1Style;
if (tok2Style != -1) {
jFormat = DateFormat.getDateTimeInstance(tok1Style, tok2Style, cacheKey.locale);
}
break;
}
}
}
if (jFormat == null) {
try {
jFormat = new SimpleDateFormat(nameOrPattern, cacheKey.locale);
} catch (IllegalArgumentException e) {
final String msg = e.getMessage();
throw new InvalidFormatParametersException(
msg != null ? msg : "Invalid SimpleDateFormat pattern", e);
}
}
jFormat.setTimeZone(cacheKey.timeZone);
if (GLOBAL_FORMAT_CACHE.size() >= LEAK_ALERT_NUMBER_FORMAT_CACHE_SIZE) {
boolean triggered = false;
synchronized (JavaTemplateNumberFormatFactory.class) {
if (GLOBAL_FORMAT_CACHE.size() >= LEAK_ALERT_NUMBER_FORMAT_CACHE_SIZE) {
triggered = true;
GLOBAL_FORMAT_CACHE.clear();
}
}
if (triggered) {
LOG.warn("Global Java DateFormat cache has exceeded " + LEAK_ALERT_NUMBER_FORMAT_CACHE_SIZE
+ " entries => cache flushed. "
+ "Typical cause: Some template generates high variety of format pattern strings.");
}
}
DateFormat prevJFormat = GLOBAL_FORMAT_CACHE.putIfAbsent(cacheKey, jFormat);
if (prevJFormat != null) {
jFormat = prevJFormat;
}
} // if cache miss
return (DateFormat) jFormat.clone(); // For thread safety
}
private static final class CacheKey {
private final int dateType;
private final String pattern;
private final Locale locale;
private final TimeZone timeZone;
CacheKey(int dateType, String pattern, Locale locale, TimeZone timeZone) {
this.dateType = dateType;
this.pattern = pattern;
this.locale = locale;
this.timeZone = timeZone;
}
@Override
public boolean equals(Object o) {
if (o instanceof CacheKey) {
CacheKey fk = (CacheKey) o;
return dateType == fk.dateType && fk.pattern.equals(pattern) && fk.locale.equals(locale)
&& fk.timeZone.equals(timeZone);
}
return false;
}
@Override
public int hashCode() {
return dateType ^ pattern.hashCode() ^ locale.hashCode() ^ timeZone.hashCode();
}
}
private int parseDateStyleToken(String token) {
if ("short".equals(token)) {
return DateFormat.SHORT;
}
if ("medium".equals(token)) {
return DateFormat.MEDIUM;
}
if ("long".equals(token)) {
return DateFormat.LONG;
}
if ("full".equals(token)) {
return DateFormat.FULL;
}
return -1;
}
}