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This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up with different versions on classes on the class path).

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/*
 * Copyright 2015 The Netty Project
 *
 * The Netty Project 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:
 *
 *   https://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 io.netty.util;

/**
 * Abstraction for hash code generation and equality comparison.
 */
public interface HashingStrategy {
    /**
     * Generate a hash code for {@code obj}.
     * 
     * This method must obey the same relationship that {@link java.lang.Object#hashCode()} has with
     * {@link java.lang.Object#equals(Object)}:
     * 

     * Calling this method multiple times with the same {@code obj} should return the same result
     * If {@link #equals(Object, Object)} with parameters {@code a} and {@code b} returns {@code true}
     * then the return value for this method for parameters {@code a} and {@code b} must return the same result
     * If {@link #equals(Object, Object)} with parameters {@code a} and {@code b} returns {@code false}
     * then the return value for this method for parameters {@code a} and {@code b} does not have to
     * return different results results. However this property is desirable.
     * if {@code obj} is {@code null} then this method return {@code 0}
     * 
     */
    int hashCode(T obj);

    /**
     * Returns {@code true} if the arguments are equal to each other and {@code false} otherwise.
     * This method has the following restrictions:
     * 
     * reflexive - {@code equals(a, a)} should return true
     * symmetric - {@code equals(a, b)} returns {@code true} if {@code equals(b, a)} returns
     * {@code true}
     * transitive - if {@code equals(a, b)} returns {@code true} and {@code equals(a, c)} returns
     * {@code true} then {@code equals(b, c)} should also return {@code true}
     * consistent - {@code equals(a, b)} should return the same result when called multiple times
     * assuming {@code a} and {@code b} remain unchanged relative to the comparison criteria
     * if {@code a} and {@code b} are both {@code null} then this method returns {@code true}
     * if {@code a} is {@code null} and {@code b} is non-{@code null}, or {@code a} is non-{@code null} and
     * {@code b} is {@code null} then this method returns {@code false}
     * 
     */
    boolean equals(T a, T b);

    /**
     * A {@link HashingStrategy} which delegates to java's {@link Object#hashCode()}
     * and {@link Object#equals(Object)}.
     */
    @SuppressWarnings("rawtypes")
    HashingStrategy JAVA_HASHER = new HashingStrategy() {
        @Override
        public int hashCode(Object obj) {
            return obj != null ? obj.hashCode() : 0;
        }

        @Override
        public boolean equals(Object a, Object b) {
            return (a == b) || (a != null && a.equals(b));
        }
    };
}