| Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
| ThreadState |
|
| 1.0;1 |
| 1 | /* | |
| 2 | * Licensed to the Apache Software Foundation (ASF) under one | |
| 3 | * or more contributor license agreements. See the NOTICE file | |
| 4 | * distributed with this work for additional information | |
| 5 | * regarding copyright ownership. The ASF licenses this file | |
| 6 | * to you under the Apache License, Version 2.0 (the | |
| 7 | * "License"); you may not use this file except in compliance | |
| 8 | * with the License. You may obtain a copy of the License at | |
| 9 | * | |
| 10 | * http://www.apache.org/licenses/LICENSE-2.0 | |
| 11 | * | |
| 12 | * Unless required by applicable law or agreed to in writing, | |
| 13 | * software distributed under the License is distributed on an | |
| 14 | * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY | |
| 15 | * KIND, either express or implied. See the License for the | |
| 16 | * specific language governing permissions and limitations | |
| 17 | * under the License. | |
| 18 | */ | |
| 19 | package org.apache.shiro.util; | |
| 20 | ||
| 21 | /** | |
| 22 | * A {@code ThreadState} instance manages any state that might need to be bound and/or restored during a thread's | |
| 23 | * execution. | |
| 24 | * <h3>Usage</h3> | |
| 25 | * Calling {@link #bind bind()} will place state on the currently executing thread to be accessed later during | |
| 26 | * the thread's execution. | |
| 27 | * <h4>WARNING</h4> | |
| 28 | * After the thread is finished executing, or if an exception occurs, any previous state <b>MUST</b> be | |
| 29 | * {@link #restore restored} to guarantee all threads stay clean in any thread-pooled environment. This should always | |
| 30 | * be done in a {@code try/finally} block: | |
| 31 | * <pre> | |
| 32 | * ThreadState state = //acquire or instantiate as necessary | |
| 33 | * try { | |
| 34 | * state.bind(); | |
| 35 | * doSomething(); //execute any logic downstream logic that might need to access the state | |
| 36 | * } <b>finally { | |
| 37 | * state.restore(); | |
| 38 | * }</b> | |
| 39 | * </pre> | |
| 40 | * | |
| 41 | * @since 1.0 | |
| 42 | */ | |
| 43 | public interface ThreadState { | |
| 44 | ||
| 45 | /** | |
| 46 | * Binds any state that should be made accessible during a thread's execution. This should typically always | |
| 47 | * be called in a {@code try/finally} block paired with the {@link #restore} call to guarantee that the thread | |
| 48 | * is cleanly restored back to its original state. For example: | |
| 49 | * <pre> | |
| 50 | * ThreadState state = //acquire or instantiate as necessary | |
| 51 | * <b>try { | |
| 52 | * state.bind(); | |
| 53 | * doSomething(); //execute any logic downstream logic that might need to access the state | |
| 54 | * } </b> finally { | |
| 55 | * state.restore(); | |
| 56 | * } | |
| 57 | * </pre> | |
| 58 | */ | |
| 59 | void bind(); | |
| 60 | ||
| 61 | /** | |
| 62 | * Restores a thread to its state before bind {@link #bind bind} was invoked. This should typically always be | |
| 63 | * called in a {@code finally} block to guarantee that the thread is cleanly restored back to its original state | |
| 64 | * before {@link #bind bind}'s bind was called. For example: | |
| 65 | * <pre> | |
| 66 | * ThreadState state = //acquire or instantiate as necessary | |
| 67 | * try { | |
| 68 | * state.bind(); | |
| 69 | * doSomething(); //execute any logic downstream logic that might need to access the state | |
| 70 | * } <b>finally { | |
| 71 | * state.restore(); | |
| 72 | * }</b> | |
| 73 | * </pre> | |
| 74 | */ | |
| 75 | void restore(); | |
| 76 | ||
| 77 | /** | |
| 78 | * Completely clears/removes the {@code ThreadContext} state. Typically this method should | |
| 79 | * only be called in special cases - it is more 'correct' to {@link #restore restore} a thread to its previous | |
| 80 | * state than to clear it entirely. | |
| 81 | */ | |
| 82 | void clear(); | |
| 83 | ||
| 84 | } |