org.springframework.security.web.access.expression.AbstractVariableEvaluationContextPostProcessor Maven / Gradle / Ivy
/*
* Copyright 2002-2015 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
*
* https://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 org.springframework.security.web.access.expression;
import java.util.Map;
import javax.servlet.http.HttpServletRequest;
import org.springframework.expression.EvaluationContext;
import org.springframework.security.web.FilterInvocation;
/**
* Exposes URI template variables as variables on the {@link EvaluationContext}. For
* example, the pattern "/user/{username}/**" would expose a variable named username based
* on the current URI.
*
*
* NOTE: This API is intentionally kept package scope as it may change in the future. It
* may be nice to allow users to augment expressions and queries
*
*
* @author Rob Winch
* @since 4.1
*/
abstract class AbstractVariableEvaluationContextPostProcessor
implements EvaluationContextPostProcessor {
@Override
public final EvaluationContext postProcess(EvaluationContext context, FilterInvocation invocation) {
return new VariableEvaluationContext(context, invocation.getHttpRequest());
}
abstract Map extractVariables(HttpServletRequest request);
/**
* {@link DelegatingEvaluationContext} to expose variable.
*/
class VariableEvaluationContext extends DelegatingEvaluationContext {
private final HttpServletRequest request;
private Map variables;
VariableEvaluationContext(EvaluationContext delegate, HttpServletRequest request) {
super(delegate);
this.request = request;
}
@Override
public Object lookupVariable(String name) {
Object result = super.lookupVariable(name);
if (result != null) {
return result;
}
if (this.variables == null) {
this.variables = extractVariables(this.request);
}
return this.variables.get(name);
}
}
}