freemarker.ext.jsp.PageContextFactory Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.ext.jsp;
import javax.servlet.jsp.PageContext;
import freemarker.core.Environment;
import freemarker.template.TemplateModel;
import freemarker.template.TemplateModelException;
import freemarker.template.utility.UndeclaredThrowableException;
/**
*/
class PageContextFactory {
private static final Class pageContextImpl = getPageContextImpl();
private static Class getPageContextImpl() {
try {
try {
PageContext.class.getMethod("getELContext", (Class[]) null);
return Class.forName("freemarker.ext.jsp._FreeMarkerPageContext21");
} catch (NoSuchMethodException e1) {
try {
PageContext.class.getMethod("getExpressionEvaluator", (Class[]) null);
return Class.forName("freemarker.ext.jsp._FreeMarkerPageContext2");
} catch (NoSuchMethodException e2) {
throw new IllegalStateException(
"Since FreeMarker 2.3.24, JSP support requires at least JSP 2.0.");
}
}
} catch (ClassNotFoundException e) {
throw new NoClassDefFoundError(e.getMessage());
}
}
static FreeMarkerPageContext getCurrentPageContext() throws TemplateModelException {
Environment env = Environment.getCurrentEnvironment();
TemplateModel pageContextModel = env.getGlobalVariable(PageContext.PAGECONTEXT);
if (pageContextModel instanceof FreeMarkerPageContext) {
return (FreeMarkerPageContext) pageContextModel;
}
try {
FreeMarkerPageContext pageContext =
(FreeMarkerPageContext) pageContextImpl.newInstance();
env.setGlobalVariable(PageContext.PAGECONTEXT, pageContext);
return pageContext;
} catch (IllegalAccessException e) {
throw new IllegalAccessError(e.getMessage());
} catch (InstantiationException e) {
throw new UndeclaredThrowableException(e);
}
}
}