001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 *  Unless required by applicable law or agreed to in writing, software
012 *  distributed under the License is distributed on an "AS IS" BASIS,
013 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 *  See the License for the specific language governing permissions and
015 *  limitations under the License.
016 *
017 */
018package org.apache.bcel.classfile;
019
020import java.io.DataInput;
021import java.io.DataOutputStream;
022import java.io.IOException;
023import java.util.ArrayList;
024import java.util.List;
025import java.util.stream.Stream;
026
027/**
028 * Represents one annotation in the annotation table
029 *
030 * @since 6.0
031 */
032public class AnnotationEntry implements Node {
033
034    public static final AnnotationEntry[] EMPTY_ARRAY = {};
035
036    public static AnnotationEntry[] createAnnotationEntries(final Attribute[] attrs) {
037        // Find attributes that contain annotation data
038        return Stream.of(attrs).filter(Annotations.class::isInstance).flatMap(e -> Stream.of(((Annotations) e).getAnnotationEntries()))
039            .toArray(AnnotationEntry[]::new);
040    }
041
042    /**
043     * Factory method to create an AnnotionEntry from a DataInput
044     *
045     * @param input
046     * @param constantPool
047     * @param isRuntimeVisible
048     * @return the entry
049     * @throws IOException if an I/O error occurs.
050     */
051    public static AnnotationEntry read(final DataInput input, final ConstantPool constantPool, final boolean isRuntimeVisible) throws IOException {
052        final AnnotationEntry annotationEntry = new AnnotationEntry(input.readUnsignedShort(), constantPool, isRuntimeVisible);
053        final int num_element_value_pairs = input.readUnsignedShort();
054        annotationEntry.elementValuePairs = new ArrayList<>();
055        for (int i = 0; i < num_element_value_pairs; i++) {
056            annotationEntry.elementValuePairs
057                .add(new ElementValuePair(input.readUnsignedShort(), ElementValue.readElementValue(input, constantPool), constantPool));
058        }
059        return annotationEntry;
060    }
061
062    private final int typeIndex;
063
064    private final ConstantPool constantPool;
065
066    private final boolean isRuntimeVisible;
067
068    private List<ElementValuePair> elementValuePairs;
069
070    public AnnotationEntry(final int type_index, final ConstantPool constant_pool, final boolean isRuntimeVisible) {
071        this.typeIndex = type_index;
072        this.constantPool = constant_pool;
073        this.isRuntimeVisible = isRuntimeVisible;
074    }
075
076    /**
077     * Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class.
078     * I.e., the hierarchy of methods, fields, attributes, etc. spawns a tree of objects.
079     *
080     * @param v Visitor object
081     */
082    @Override
083    public void accept(final Visitor v) {
084        v.visitAnnotationEntry(this);
085    }
086
087    public void addElementNameValuePair(final ElementValuePair elementNameValuePair) {
088        elementValuePairs.add(elementNameValuePair);
089    }
090
091    public void dump(final DataOutputStream dos) throws IOException {
092        dos.writeShort(typeIndex); // u2 index of type name in cpool
093        dos.writeShort(elementValuePairs.size()); // u2 element_value pair
094        // count
095        for (final ElementValuePair envp : elementValuePairs) {
096            envp.dump(dos);
097        }
098    }
099
100    /**
101     * @return the annotation type name
102     */
103    public String getAnnotationType() {
104        return constantPool.getConstantUtf8(typeIndex).getBytes();
105    }
106
107    /**
108     * @return the annotation type index
109     */
110    public int getAnnotationTypeIndex() {
111        return typeIndex;
112    }
113
114    public ConstantPool getConstantPool() {
115        return constantPool;
116    }
117
118    /**
119     * @return the element value pairs in this annotation entry
120     */
121    public ElementValuePair[] getElementValuePairs() {
122        // TODO return List
123        return elementValuePairs.toArray(ElementValuePair.EMPTY_ARRAY);
124    }
125
126    /**
127     * @return the number of element value pairs in this annotation entry
128     */
129    public final int getNumElementValuePairs() {
130        return elementValuePairs.size();
131    }
132
133    public int getTypeIndex() {
134        return typeIndex;
135    }
136
137    public boolean isRuntimeVisible() {
138        return isRuntimeVisible;
139    }
140
141    public String toShortString() {
142        final StringBuilder result = new StringBuilder();
143        result.append("@");
144        result.append(getAnnotationType());
145        final ElementValuePair[] evPairs = getElementValuePairs();
146        if (evPairs.length > 0) {
147            result.append("(");
148            for (final ElementValuePair element : evPairs) {
149                result.append(element.toShortString());
150                result.append(", ");
151            }
152            // remove last ", "
153            result.setLength(result.length() - 2);
154            result.append(")");
155        }
156        return result.toString();
157    }
158
159    @Override
160    public String toString() {
161        return toShortString();
162    }
163}