/*
* Copyright 2002-2016 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.
*/
package org.springframework.security.concurrent;
import java.util.concurrent.Callable;
import org.springframework.security.core.context.SecurityContext;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.util.Assert;
/**
* <p>
* Wraps a delegate {@link Callable} with logic for setting up a
* {@link SecurityContext} before invoking the delegate {@link Callable} and
* then removing the {@link SecurityContext} after the delegate has completed.
* </p>
* <p>
* If there is a {@link SecurityContext} that already exists, it will be
* restored after the {@link #call()} method is invoked.
* </p>
*
* @author Rob Winch
* @since 3.2
*/
public final class DelegatingSecurityContextCallable<V> implements Callable<V> {
private final Callable<V> delegate;
/**
* The {@link SecurityContext} that the delegate {@link Callable} will be
* ran as.
*/
private final SecurityContext delegateSecurityContext;
/**
* The {@link SecurityContext} that was on the {@link SecurityContextHolder}
* prior to being set to the delegateSecurityContext.
*/
private SecurityContext originalSecurityContext;
/**
* Creates a new {@link DelegatingSecurityContextCallable} with a specific
* {@link SecurityContext}.
* @param delegate the delegate {@link DelegatingSecurityContextCallable} to run with
* the specified {@link SecurityContext}. Cannot be null.
* @param securityContext the {@link SecurityContext} to establish for the delegate
* {@link Callable}. Cannot be null.
*/
public DelegatingSecurityContextCallable(Callable<V> delegate,
SecurityContext securityContext) {
Assert.notNull(delegate, "delegate cannot be null");
Assert.notNull(securityContext, "securityContext cannot be null");
this.delegate = delegate;
this.delegateSecurityContext = securityContext;
}
/**
* Creates a new {@link DelegatingSecurityContextCallable} with the
* {@link SecurityContext} from the {@link SecurityContextHolder}.
* @param delegate the delegate {@link Callable} to run under the current
* {@link SecurityContext}. Cannot be null.
*/
public DelegatingSecurityContextCallable(Callable<V> delegate) {
this(delegate, SecurityContextHolder.getContext());
}
public V call() throws Exception {
this.originalSecurityContext = SecurityContextHolder.getContext();
try {
SecurityContextHolder.setContext(delegateSecurityContext);
return delegate.call();
}
finally {
SecurityContext emptyContext = SecurityContextHolder.createEmptyContext();
if(emptyContext.equals(originalSecurityContext)) {
SecurityContextHolder.clearContext();
} else {
SecurityContextHolder.setContext(originalSecurityContext);
}
this.originalSecurityContext = null;
}
}
public String toString() {
return delegate.toString();
}
/**
* Creates a {@link DelegatingSecurityContextCallable} and with the given
* {@link Callable} and {@link SecurityContext}, but if the securityContext is null
* will defaults to the current {@link SecurityContext} on the
* {@link SecurityContextHolder}
*
* @param delegate the delegate {@link DelegatingSecurityContextCallable} to run with
* the specified {@link SecurityContext}. Cannot be null.
* @param securityContext the {@link SecurityContext} to establish for the delegate
* {@link Callable}. If null, defaults to {@link SecurityContextHolder#getContext()}
* @return
*/
public static <V> Callable<V> create(Callable<V> delegate,
SecurityContext securityContext) {
return securityContext == null ? new DelegatingSecurityContextCallable<V>(
delegate) : new DelegatingSecurityContextCallable<V>(delegate,
securityContext);
}
}