com.baidu.bjf.remoting.protobuf.utils.MiniTemplatorCache Maven / Gradle / Ivy
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/*
* Copyright 2002-2007 the original author or authors.
*
* 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.
*/
// Copyright 2003-2010 Christian d'Heureuse, Inventec Informatik AG, Zurich, Switzerland
// www.source-code.biz, www.inventec.ch/chdh
//
// This module is multi-licensed and may be used under the terms
// of any of the following licenses:
//
// EPL, Eclipse Public License, http://www.eclipse.org/legal
// LGPL, GNU Lesser General Public License, http://www.gnu.org/licenses/lgpl.html
//
// This module is provided "as is", without warranties of any kind.
package com.baidu.bjf.remoting.protobuf.utils;
import java.io.IOException;
import java.util.HashMap;
/**
* A cache manager for MiniTemplator objects. This class is used to cache MiniTemplator objects in memory, so that each
* template file is only read and parsed once.
*
*
* Example of how to use the template cache:
*
*
* private static MiniTemplatorCache miniTemplatorCache = new MiniTemplatorCache();
*
* public static MiniTemplator getTemplate(String templateFileName, Set flags) throws Exception {
* MiniTemplator.TemplateSpecification templateSpec = new MiniTemplator.TemplateSpecification();
* templateSpec.templateFileName = templateFileName;
* templateSpec.conditionFlags = flags;
* return miniTemplatorCache.get(templateSpec);
* };
*
*
*
* Home page: www.source-code.biz/MiniTemplator
* Author: Christian d'Heureuse, Inventec Informatik AG, Zurich, Switzerland
* Multi-licensed: EPL / LGPL.
*/
public class MiniTemplatorCache {
private HashMap cache; // buffered MiniTemplator objects
/**
* Creates a new MiniTemplatorCache object.
*/
public MiniTemplatorCache() {
cache = new HashMap();
}
/**
* Returns a cloned MiniTemplator object from the cache. If there is not yet a MiniTemplator object with the
* specified templateFileName in the cache, a new MiniTemplator object is created and stored in the
* cache. Then the cached MiniTemplator object is cloned and the clone object is returned.
*
* @param templateSpec the template specification.
* @return a cloned and reset MiniTemplator object.
*/
public synchronized MiniTemplator get(MiniTemplator.TemplateSpecification templateSpec)
throws IOException, MiniTemplator.TemplateSyntaxException {
String key = generateCacheKey(templateSpec);
MiniTemplator mt = cache.get(key);
if (mt == null) {
mt = new MiniTemplator(templateSpec);
cache.put(key, mt);
}
return mt.cloneReset();
}
private static String generateCacheKey(MiniTemplator.TemplateSpecification templateSpec) {
StringBuilder key = new StringBuilder(128);
if (templateSpec.templateText != null)
key.append(templateSpec.templateText);
else if (templateSpec.templateFileName != null) {
key.append(templateSpec.templateFileName);
} else
throw new IllegalArgumentException("No templateFileName or templateText specified.");
if (templateSpec.conditionFlags != null) {
for (String flag : templateSpec.conditionFlags) {
key.append('|');
key.append(flag.toUpperCase());
}
}
return key.toString();
}
/**
* Clears the cache.
*/
public synchronized void clear() {
cache.clear();
}
} // end class MiniTemplatorCache