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Google App Engine compliant variation of FreeMarker.
FreeMarker is a "template engine"; a generic tool to generate text output based on templates.
/*
* 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.core;
import freemarker.template.Template;
import freemarker.template.TemplateException;
import freemarker.template.utility.ClassUtil;
import freemarker.template.utility.Execute;
import freemarker.template.utility.ObjectConstructor;
/**
* Used by built-ins and other template language features that get a class
* based on a string. This can be handy both for implementing security
* restrictions and for working around local class-loader issues.
*
* The implementation should be thread-safe, unless an
* instance is always only used in a single {@link Environment} object.
*
* @see Configurable#setNewBuiltinClassResolver(TemplateClassResolver)
*
* @since 2.3.17
*/
public interface TemplateClassResolver {
/**
* Simply calls {@link ClassUtil#forName(String)}.
*/
TemplateClassResolver UNRESTRICTED_RESOLVER = new TemplateClassResolver() {
@Override
public Class resolve(String className, Environment env, Template template)
throws TemplateException {
try {
return ClassUtil.forName(className);
} catch (ClassNotFoundException e) {
throw new _MiscTemplateException(e, env);
}
}
};
/**
* Same as {@link #UNRESTRICTED_RESOLVER}, except that it doesn't allow
* resolving {@link ObjectConstructor} and {@link Execute} and {@code freemarker.template.utility.JythonRuntime}.
*/
TemplateClassResolver SAFER_RESOLVER = new TemplateClassResolver() {
@Override
public Class resolve(String className, Environment env, Template template)
throws TemplateException {
if (className.equals(ObjectConstructor.class.getName())
|| className.equals(Execute.class.getName())
|| className.equals("freemarker.template.utility.JythonRuntime")) {
throw _MessageUtil.newInstantiatingClassNotAllowedException(className, env);
}
try {
return ClassUtil.forName(className);
} catch (ClassNotFoundException e) {
throw new _MiscTemplateException(e, env);
}
}
};
/**
* Doesn't allow resolving any classes.
*/
TemplateClassResolver ALLOWS_NOTHING_RESOLVER = new TemplateClassResolver() {
@Override
public Class resolve(String className, Environment env, Template template)
throws TemplateException {
throw _MessageUtil.newInstantiatingClassNotAllowedException(className, env);
}
};
/**
* Gets a {@link Class} based on the class name.
*
* @param className the full-qualified class name
* @param env the environment in which the template executes
* @param template the template where the operation that require the
* class resolution resides in. This is null if the
* call doesn't come from a template.
*
* @throws TemplateException if the class can't be found or shouldn't be
* accessed from a template for security reasons.
*/
Class resolve(String className, Environment env, Template template) throws TemplateException;
}