org.springframework.core.Ordered.java Source code

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Here is the source code for org.springframework.core.Ordered.java

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/*
 * Copyright 2002-2015 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
 *
 *      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 org.springframework.core;

/**
 * {@code Ordered} is an interface that can be implemented by objects that
 * should be <em>orderable</em>, for example in a {@code Collection}.
 *
 * <p>The actual {@link #getOrder() order} can be interpreted as prioritization,
 * with the first object (with the lowest order value) having the highest
 * priority.
 *
 * <p>Note that there is also a <em>priority</em> marker for this interface:
 * {@link PriorityOrdered}. Order values expressed by {@code PriorityOrdered}
 * objects always apply before same order values expressed by <em>plain</em>
 * {@link Ordered} objects.
 *
 * <p>Consult the Javadoc for {@link OrderComparator} for details on the
 * sort semantics for non-ordered objects.
 *
 * @author Juergen Hoeller
 * @author Sam Brannen
 * @since 07.04.2003
 * @see PriorityOrdered
 * @see OrderComparator
 * @see org.springframework.core.annotation.Order
 * @see org.springframework.core.annotation.AnnotationAwareOrderComparator
 */
public interface Ordered {

    /**
     * Useful constant for the highest precedence value.
     * @see java.lang.Integer#MIN_VALUE
     */
    int HIGHEST_PRECEDENCE = Integer.MIN_VALUE;

    /**
     * Useful constant for the lowest precedence value.
     * @see java.lang.Integer#MAX_VALUE
     */
    int LOWEST_PRECEDENCE = Integer.MAX_VALUE;

    /**
     * Get the order value of this object.
     * <p>Higher values are interpreted as lower priority. As a consequence,
     * the object with the lowest value has the highest priority (somewhat
     * analogous to Servlet {@code load-on-startup} values).
     * <p>Same order values will result in arbitrary sort positions for the
     * affected objects.
     * @return the order value
     * @see #HIGHEST_PRECEDENCE
     * @see #LOWEST_PRECEDENCE
     */
    int getOrder();

}