| /* |
| * 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 org.apache.shiro.util; |
| |
| /** |
| * A {@code ThreadState} instance manages any state that might need to be bound and/or restored during a thread's |
| * execution. |
| * <h3>Usage</h3> |
| * Calling {@link #bind bind()} will place state on the currently executing thread to be accessed later during |
| * the thread's execution. |
| * <h4>WARNING</h4> |
| * After the thread is finished executing, or if an exception occurs, any previous state <b>MUST</b> be |
| * {@link #restore restored} to guarantee all threads stay clean in any thread-pooled environment. This should always |
| * be done in a {@code try/finally} block: |
| * <pre> |
| * ThreadState state = //acquire or instantiate as necessary |
| * try { |
| * state.bind(); |
| * doSomething(); //execute any logic downstream logic that might need to access the state |
| * } <b>finally { |
| * state.restore(); |
| * }</b> |
| * </pre> |
| * |
| * @since 1.0 |
| */ |
| public interface ThreadState { |
| |
| /** |
| * Binds any state that should be made accessible during a thread's execution. This should typically always |
| * be called in a {@code try/finally} block paired with the {@link #restore} call to guarantee that the thread |
| * is cleanly restored back to its original state. For example: |
| * <pre> |
| * ThreadState state = //acquire or instantiate as necessary |
| * <b>try { |
| * state.bind(); |
| * doSomething(); //execute any logic downstream logic that might need to access the state |
| * } </b> finally { |
| * state.restore(); |
| * } |
| * </pre> |
| */ |
| void bind(); |
| |
| /** |
| * Restores a thread to its state before bind {@link #bind bind} was invoked. This should typically always be |
| * called in a {@code finally} block to guarantee that the thread is cleanly restored back to its original state |
| * before {@link #bind bind}'s bind was called. For example: |
| * <pre> |
| * ThreadState state = //acquire or instantiate as necessary |
| * try { |
| * state.bind(); |
| * doSomething(); //execute any logic downstream logic that might need to access the state |
| * } <b>finally { |
| * state.restore(); |
| * }</b> |
| * </pre> |
| */ |
| void restore(); |
| |
| /** |
| * Completely clears/removes the {@code ThreadContext} state. Typically this method should |
| * only be called in special cases - it is more 'correct' to {@link #restore restore} a thread to its previous |
| * state than to clear it entirely. |
| */ |
| void clear(); |
| |
| } |