1 /* 2 * Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package jdk.jfr.internal; 27 28 import java.lang.annotation.Annotation; 29 import java.lang.reflect.InvocationHandler; 30 import java.lang.reflect.Method; 31 import java.lang.reflect.Proxy; 32 import java.util.Collections; 33 import java.util.List; 34 35 import jdk.jfr.AnnotationElement; 36 import jdk.jfr.Description; 37 import jdk.jfr.Label; 38 import jdk.jfr.Unsigned; 39 40 public final class AnnotationConstruct { 41 42 private static final class AnnotationInvokationHandler implements InvocationHandler { 43 44 private final AnnotationElement annotationElement; 45 46 AnnotationInvokationHandler(AnnotationElement a) { 47 this.annotationElement = a; 48 } 49 50 @Override 51 public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { 52 String methodName = method.getName(); 53 int parameters = method.getTypeParameters().length; 54 if (parameters == 0 && annotationElement.hasValue(methodName)) { 55 return annotationElement.getValue(methodName); 56 } 57 throw new UnsupportedOperationException("Flight Recorder proxy only supports members declared in annotation interfaces, i.e. not toString, equals etc."); 58 } 59 } 60 61 private List<AnnotationElement> annotationElements = Collections.emptyList(); 62 private byte unsignedFlag = -1; 63 public AnnotationConstruct(List<AnnotationElement> ann) { 64 this.annotationElements = ann; 65 } 66 67 public AnnotationConstruct() { 68 } 69 70 public void setAnnotationElements(List<AnnotationElement> elements) { 71 annotationElements = Utils.smallUnmodifiable(elements); 72 } 73 74 public String getLabel() { 75 Label label = getAnnotation(Label.class); 76 if (label == null) { 77 return null; 78 } 79 return label.value(); 80 } 81 82 public String getDescription() { 83 Description description = getAnnotation(Description.class); 84 if (description == null) { 85 return null; 86 } 87 return description.value(); 88 } 89 90 @SuppressWarnings("unchecked") 91 public final <T> T getAnnotation(Class<? extends Annotation> clazz) { 92 AnnotationElement ae = getAnnotationElement(clazz); 93 if (ae != null) { 94 return (T) Proxy.newProxyInstance(clazz.getClassLoader(), new Class<?>[] { clazz }, new AnnotationInvokationHandler(ae)); 95 } 96 return null; 97 } 98 99 public List<AnnotationElement> getUnmodifiableAnnotationElements() { 100 return annotationElements; 101 } 102 103 // package private 104 boolean remove(AnnotationElement annotation) { 105 return annotationElements.remove(annotation); 106 } 107 108 private AnnotationElement getAnnotationElement(Class<? extends Annotation> clazz) { 109 // if multiple annotation elements with the same name exists, prioritize 110 // the one with the same id. Note, id alone is not a guarantee, since it 111 // may differ between JVM instances. 112 long id = Type.getTypeId(clazz); 113 String className = clazz.getName(); 114 for (AnnotationElement a : getUnmodifiableAnnotationElements()) { 115 if (a.getTypeId() == id && a.getTypeName().equals(className)) { 116 return a; 117 } 118 } 119 for (AnnotationElement a : getUnmodifiableAnnotationElements()) { 120 if (a.getTypeName().equals(className)) { 121 return a; 122 } 123 } 124 return null; 125 } 126 127 public boolean hasUnsigned() { 128 // Must be initialized lazily since some annotation elements 129 // are added after construction 130 if (unsignedFlag < 0) { 131 Unsigned unsigned = getAnnotation(Unsigned.class); 132 unsignedFlag = (byte) (unsigned == null ? 0 :1); 133 } 134 return unsignedFlag == (byte)1 ? true : false; 135 } 136 }