1 /* 2 * Grapht, an open source dependency injector. 3 * Copyright 2014-2015 various contributors (see CONTRIBUTORS.txt) 4 * Copyright 2010-2014 Regents of the University of Minnesota 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU Lesser General Public License as 8 * published by the Free Software Foundation; either version 2.1 of the 9 * License, or (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 13 * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more 14 * details. 15 * 16 * You should have received a copy of the GNU General Public License along with 17 * this program; if not, write to the Free Software Foundation, Inc., 51 18 * Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 19 */ 20 package org.grouplens.grapht.reflect; 21 22 import com.google.common.base.Predicate; 23 24 import javax.annotation.Nullable; 25 import javax.inject.Qualifier; 26 import java.io.Serializable; 27 import java.lang.annotation.Annotation; 28 29 30 /** 31 * <p> 32 * QualifierMatcher encapsulates the logic used to determine if a BindRule or 33 * ContextElementMatcher match a particular Qualifier. Common qualifier matching rules 34 * are: 35 * <ol> 36 * <li>Any qualifier</li> 37 * <li>No qualifier</li> 38 * <li>Annotation type</li> 39 * <li>Annotation instance equality</li> 40 * </ol> 41 * All QualifierMatchers created by the same InjectSPI must be comparable, 42 * matchers from different SPIs do not need to be comparable. 43 * 44 * @author <a href="http://grouplens.org">GroupLens Research</a> 45 */ 46 public interface QualifierMatcher extends Predicate<Annotation>, Comparable<QualifierMatcher>, Serializable { 47 /** 48 * Return true if this matcher matches the given qualifier annotation. It 49 * can be assumed that the annotation type has been annotated with 50 * {@link Qualifier}. The qualifier will be null if the injection point 51 * being matched did not have a qualifier. 52 * 53 * @param q The qualifier to match 54 * @return True if matched 55 */ 56 boolean matches(@Nullable Annotation q); 57 58 /** 59 * Return true if this matcher matches the given qualifier annotation. It 60 * can be assumed that the annotation type has been annotated with 61 * {@link Qualifier}. The qualifier will be null if the injection point 62 * being matched did not have a qualifier. 63 * 64 * @param q The qualifier to match 65 * @return True if matched 66 */ 67 @Override 68 boolean apply(@Nullable Annotation q); 69 70 /** 71 * Get the priority of this matcher. Lower priority values have precedence in selecting 72 * the final bind rule. All Grapht matchers have priorities of at least 0; negative 73 * priority values are reserved for custom extensions. 74 * 75 * @return The priority. 76 */ 77 int getPriority(); 78 }