https://github.com/Netflix/Hystrix: hystrix-core
  • Netflix Open Source Development 
Copyright 2012 Netflix, Inc.
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
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/**
 * Copyright 2012 Netflix, Inc.
 *
 * 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 com.netflix.hystrix.strategy.concurrency;

import com.netflix.hystrix.strategy.HystrixPlugins;


Interface for a variable similar to ThreadLocal but scoped at the user request level. 
 Default implementation is HystrixRequestVariableDefault managed by HystrixRequestContext. 
 Custom implementations can be injected using HystrixPlugins and HystrixConcurrencyStrategy.getRequestVariable. 
 See JavaDoc of HystrixRequestContext for more information about functionality this enables and how to use the default implementation. 
Type parameters:
  • <T> – 
           Type to be stored on the HystrixRequestVariable
/**
 * Interface for a variable similar to {@link ThreadLocal} but scoped at the user request level.
 * <p>
 * Default implementation is {@link HystrixRequestVariableDefault} managed by {@link HystrixRequestContext}.
 * <p>
 * Custom implementations can be injected using {@link HystrixPlugins} and {@link HystrixConcurrencyStrategy#getRequestVariable}.
 * <p>
 * See JavaDoc of {@link HystrixRequestContext} for more information about functionality this enables and how to use the default implementation.
 * 
 * @param <T>
 *            Type to be stored on the HystrixRequestVariable
 */
public interface HystrixRequestVariable<T> extends HystrixRequestVariableLifecycle<T> {

    
Retrieve current value or initialize and then return value for this variable for the current request scope.

Returns:T value of variable for current request scope.
/**
     * Retrieve current value or initialize and then return value for this variable for the current request scope.
     * 
     * @return T value of variable for current request scope.
     */
    public T get();

}