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 */
017package org.apache.bcel.classfile;
018
019import java.io.DataInput;
020import java.io.DataOutputStream;
021import java.io.IOException;
022import java.util.ArrayList;
023import java.util.List;
024import java.util.stream.Stream;
025
026/**
027 * Represents one annotation in the annotation table
028 *
029 * @since 6.0
030 */
031public class AnnotationEntry implements Node {
032
033    public static final AnnotationEntry[] EMPTY_ARRAY = {};
034
035    public static AnnotationEntry[] createAnnotationEntries(final Attribute[] attrs) {
036        // Find attributes that contain annotation data
037        return Stream.of(attrs).filter(Annotations.class::isInstance).flatMap(e -> Stream.of(((Annotations) e).getAnnotationEntries()))
038            .toArray(AnnotationEntry[]::new);
039    }
040
041    /**
042     * Factory method to create an AnnotionEntry from a DataInput
043     *
044     * @param input
045     * @param constantPool
046     * @param isRuntimeVisible
047     * @return the entry
048     * @throws IOException if an I/O error occurs.
049     */
050    public static AnnotationEntry read(final DataInput input, final ConstantPool constantPool, final boolean isRuntimeVisible) throws IOException {
051        final AnnotationEntry annotationEntry = new AnnotationEntry(input.readUnsignedShort(), constantPool, isRuntimeVisible);
052        final int numElementValuePairs = input.readUnsignedShort();
053        for (int i = 0; i < numElementValuePairs; i++) {
054            annotationEntry.elementValuePairs
055                .add(new ElementValuePair(input.readUnsignedShort(), ElementValue.readElementValue(input, constantPool), constantPool));
056        }
057        return annotationEntry;
058    }
059
060    private final int typeIndex;
061
062    private final ConstantPool constantPool;
063
064    private final boolean isRuntimeVisible;
065
066    private final List<ElementValuePair> elementValuePairs;
067
068    public AnnotationEntry(final int typeIndex, final ConstantPool constantPool, final boolean isRuntimeVisible) {
069        this.typeIndex = typeIndex;
070        this.constantPool = constantPool;
071        this.isRuntimeVisible = isRuntimeVisible;
072        this.elementValuePairs = new ArrayList<>();
073    }
074
075    /**
076     * Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class.
077     * I.e., the hierarchy of methods, fields, attributes, etc. spawns a tree of objects.
078     *
079     * @param v Visitor object
080     */
081    @Override
082    public void accept(final Visitor v) {
083        v.visitAnnotationEntry(this);
084    }
085
086    public void addElementNameValuePair(final ElementValuePair elementNameValuePair) {
087        elementValuePairs.add(elementNameValuePair);
088    }
089
090    public void dump(final DataOutputStream dos) throws IOException {
091        dos.writeShort(typeIndex); // u2 index of type name in cpool
092        dos.writeShort(elementValuePairs.size()); // u2 element_value pair
093        // count
094        for (final ElementValuePair envp : elementValuePairs) {
095            envp.dump(dos);
096        }
097    }
098
099    /**
100     * @return the annotation type name
101     */
102    public String getAnnotationType() {
103        return constantPool.getConstantUtf8(typeIndex).getBytes();
104    }
105
106    /**
107     * @return the annotation type index
108     */
109    public int getAnnotationTypeIndex() {
110        return typeIndex;
111    }
112
113    public ConstantPool getConstantPool() {
114        return constantPool;
115    }
116
117    /**
118     * @return the element value pairs in this annotation entry
119     */
120    public ElementValuePair[] getElementValuePairs() {
121        // TODO return List
122        return elementValuePairs.toArray(ElementValuePair.EMPTY_ARRAY);
123    }
124
125    /**
126     * @return the number of element value pairs in this annotation entry
127     */
128    public final int getNumElementValuePairs() {
129        return elementValuePairs.size();
130    }
131
132    public int getTypeIndex() {
133        return typeIndex;
134    }
135
136    public boolean isRuntimeVisible() {
137        return isRuntimeVisible;
138    }
139
140    public String toShortString() {
141        final StringBuilder result = new StringBuilder();
142        result.append("@");
143        result.append(getAnnotationType());
144        final ElementValuePair[] evPairs = getElementValuePairs();
145        if (evPairs.length > 0) {
146            result.append("(");
147            for (final ElementValuePair element : evPairs) {
148                result.append(element.toShortString());
149                result.append(", ");
150            }
151            // remove last ", "
152            result.setLength(result.length() - 2);
153            result.append(")");
154        }
155        return result.toString();
156    }
157
158    @Override
159    public String toString() {
160        return toShortString();
161    }
162}