1 /* 2 * Copyright (C) 2021 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.annotationvisitor; 18 19 import com.google.common.base.Preconditions; 20 21 import org.apache.bcel.classfile.AnnotationElementValue; 22 import org.apache.bcel.classfile.AnnotationEntry; 23 import org.apache.bcel.classfile.ArrayElementValue; 24 import org.apache.bcel.classfile.ElementValue; 25 import org.apache.bcel.classfile.ElementValuePair; 26 27 /** 28 * Handles a repeated annotation container. 29 * 30 * <p>The enclosed annotations are passed to the {@link #mWrappedHandler}. 31 */ 32 public class RepeatedAnnotationHandler extends AnnotationHandler { 33 34 private static final String VALUE = "value"; 35 36 private final AnnotationHandler mWrappedHandler; 37 private final String mInnerAnnotationName; 38 RepeatedAnnotationHandler(String innerAnnotationName, AnnotationHandler wrappedHandler)39 public RepeatedAnnotationHandler(String innerAnnotationName, AnnotationHandler wrappedHandler) { 40 mWrappedHandler = wrappedHandler; 41 mInnerAnnotationName = innerAnnotationName; 42 } 43 44 @Override handleAnnotation(AnnotationEntry annotation, AnnotationContext context)45 public void handleAnnotation(AnnotationEntry annotation, AnnotationContext context) { 46 // Verify that the annotation has the form we expect 47 ElementValuePair value = findValue(annotation); 48 if (value == null) { 49 context.reportError("No value found on %s", annotation.getAnnotationType()); 50 return; 51 } 52 Preconditions.checkArgument(value.getValue() instanceof ArrayElementValue); 53 ArrayElementValue array = (ArrayElementValue) value.getValue(); 54 55 // call wrapped handler on each enclosed annotation: 56 for (ElementValue v : array.getElementValuesArray()) { 57 Preconditions.checkArgument(v instanceof AnnotationElementValue); 58 AnnotationElementValue aev = (AnnotationElementValue) v; 59 Preconditions.checkArgument( 60 aev.getAnnotationEntry().getAnnotationType().equals(mInnerAnnotationName)); 61 mWrappedHandler.handleAnnotation(aev.getAnnotationEntry(), context); 62 } 63 } 64 findValue(AnnotationEntry a)65 private ElementValuePair findValue(AnnotationEntry a) { 66 for (ElementValuePair property : a.getElementValuePairs()) { 67 if (property.getNameString().equals(VALUE)) { 68 return property; 69 } 70 } 71 // not found 72 return null; 73 } 74 } 75