/**
* jetbrick-template
* http://subchen.github.io/jetbrick-template/
*
* Copyright 2010-2014 Guoqiang Chen. All rights reserved.
* Email: subchen@gmail.com
*
* 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 jetbrick.template.web;
import javax.servlet.*;
import jetbrick.template.JetConfig;
import jetbrick.template.JetEngine;
/**
* 自动初始化加载 JetEngine。
* <pre><xmp>
* <context-param>
* <param-name>jetbrick-template-config-location</param-name>
* <param-value>/WEB-INF/jetbrick-template.properties</param-value>
* </context-param>
*
* <listener>
* <listener-class>jetbrick.template.web.JetWebEngineLoader</listener-class>
* </listener>
* </xmp></pre>
*/
public class JetWebEngineLoader implements ServletContextListener {
private static final String CONFIG_LOCATION = "jetbrick-template-config-location";
private static JetEngine engine;
public static boolean unavailable() {
return engine == null;
}
public static JetEngine getJetEngine() {
if (engine == null) {
throw new IllegalStateException("Please add JetWebEngineLoader as listener into web.xml");
}
return engine;
}
public static String getTemplateSuffix() {
if (engine == null) {
throw new IllegalStateException("Please add JetWebEngineLoader as listener into web.xml");
}
return engine.getConfig().getTemplateSuffix();
}
// 允许非 ServletContextListener 方式初始化
public static void setServletContext(ServletContext servletContext) {
if (engine == null) {
initJetWebEngine(servletContext);
}
}
private static void initJetWebEngine(ServletContext sc) {
// 设置环境变量，以便 JetConfig 能够读取该变量
String webappdir = sc.getRealPath("/");
if (webappdir != null) {
// 在 weblogic 中以 war 方式部署的时候，无法使用 getRealPath 方法.
System.setProperty("webapp.dir", webappdir);
}
JetConfig config = new JetConfig();
config.load(JetConfig.TEMPLATE_LOADER, WebResourceLoader.class.getName());
config.load(JetConfig.TEMPLATE_PATH, "/"); // 默认 Webapp 根目录
String location = sc.getInitParameter(CONFIG_LOCATION);
if (location != null && location.length() > 0) {
config.loadSerlvetResource(sc, location);
} else {
config.loadClasspath(JetConfig.DEFAULT_CONFIG_FILE);
}
engine = new JetWebEngine(config, sc);
}
@Override
public void contextInitialized(ServletContextEvent sce) {
initJetWebEngine(sce.getServletContext());
}
@Override
public void contextDestroyed(ServletContextEvent sce) {
engine = null;
}
}