/*
* Copyright 2006-2007 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.batch.repeat.support;
import org.springframework.batch.repeat.RepeatCallback;
import org.springframework.batch.repeat.RepeatContext;
import org.springframework.batch.repeat.RepeatOperations;
/**
* Global variable support for repeat clients. Normally it is not necessary for
* clients to be aware of the surrounding environment because a
* {@link RepeatCallback} can always use the context it is passed by the
* enclosing {@link RepeatOperations}. But occasionally it might be helpful to
* have lower level access to the ongoing {@link RepeatContext} so we provide a
* global accessor here. The mutator methods ({@link #clear()} and
* {@link #register(RepeatContext)} should not be used except internally by
* {@link RepeatOperations} implementations.
*
* @author Dave Syer
*
*/
public final class RepeatSynchronizationManager {
private static final ThreadLocal<RepeatContext> contextHolder = new ThreadLocal<RepeatContext>();
private RepeatSynchronizationManager() {
}
/**
* Getter for the current context. A context is shared by all items in the
* batch, so this method is intended to return the same context object
* independent of whether the callback is running synchronously or
* asynchronously with the surrounding {@link RepeatOperations}.
*
* @return the current {@link RepeatContext} or null if there is none (if we
* are not in a batch).
*/
public static RepeatContext getContext() {
return contextHolder.get();
}
/**
* Convenience method to set the current repeat operation to complete if it
* exists.
*/
public static void setCompleteOnly() {
RepeatContext context = getContext();
if (context != null) {
context.setCompleteOnly();
}
}
/**
* Method for registering a context - should only be used by
* {@link RepeatOperations} implementations to ensure that
* {@link #getContext()} always returns the correct value.
*
* @param context a new context at the start of a batch.
* @return the old value if there was one.
*/
public static RepeatContext register(RepeatContext context) {
RepeatContext oldSession = getContext();
RepeatSynchronizationManager.contextHolder.set(context);
return oldSession;
}
/**
* Clear the current context at the end of a batch - should only be used by
* {@link RepeatOperations} implementations.
*
* @return the old value if there was one.
*/
public static RepeatContext clear() {
RepeatContext context = getContext();
RepeatSynchronizationManager.contextHolder.set(null);
return context;
}
/**
* Set current session and all ancestors (via parent) to complete.,
*/
public static void setAncestorsCompleteOnly() {
RepeatContext context = getContext();
while (context != null) {
context.setCompleteOnly();
context = context.getParent();
}
}
}