Copyright (c) 2004, 2009 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
/*******************************************************************************
 * Copyright (c) 2004, 2009 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jdt.internal.core.util;

import org.eclipse.jdt.core.util.ClassFormatException;
import org.eclipse.jdt.core.util.IAnnotation;
import org.eclipse.jdt.core.util.IAnnotationComponent;
import org.eclipse.jdt.core.util.IConstantPool;
import org.eclipse.jdt.core.util.IConstantPoolConstant;
import org.eclipse.jdt.core.util.IConstantPoolEntry;

Default implementation of IAnnotation
/**
 * Default implementation of IAnnotation
 */
public class Annotation extends ClassFileStruct implements IAnnotation {

	private static final IAnnotationComponent[] NO_ENTRIES = new IAnnotationComponent[0];

	private int typeIndex;
	private char[] typeName;
	private int componentsNumber;
	private IAnnotationComponent[] components;
	private int readOffset;

	
Constructor for Annotation.
Params:
classFileBytes – 
constantPool – 
offset – 
Throws:
ClassFormatException – /**
	 * Constructor for Annotation.
	 *
	 * @param classFileBytes
	 * @param constantPool
	 * @param offset
	 * @throws ClassFormatException
	 */
	public Annotation(
			byte[] classFileBytes,
			IConstantPool constantPool,
			int offset) throws ClassFormatException {

		final int index = u2At(classFileBytes, 0, offset);
		this.typeIndex = index;
		if (index != 0) {
			IConstantPoolEntry constantPoolEntry = constantPool.decodeEntry(index);
			if (constantPoolEntry.getKind() != IConstantPoolConstant.CONSTANT_Utf8) {
				throw new ClassFormatException(ClassFormatException.INVALID_CONSTANT_POOL_ENTRY);
			}
			this.typeName = constantPoolEntry.getUtf8Value();
		} else {
			throw new ClassFormatException(ClassFormatException.INVALID_CONSTANT_POOL_ENTRY);
		}
		final int length = u2At(classFileBytes, 2, offset);
		this.componentsNumber = length;
		this.readOffset = 4;
		if (length != 0) {
			this.components = new IAnnotationComponent[length];
			for (int i = 0; i < length; i++) {
				AnnotationComponent component = new AnnotationComponent(classFileBytes, constantPool, offset + this.readOffset);
				this.components[i] = component;
				this.readOffset += component.sizeInBytes();
			}
		} else {
			this.components = NO_ENTRIES;
		}
	}

	@Override
	public int getTypeIndex() {
		return this.typeIndex;
	}

	@Override
	public int getComponentsNumber() {
		return this.componentsNumber;
	}

	@Override
	public IAnnotationComponent[] getComponents() {
		return this.components;
	}

	int sizeInBytes() {
		return this.readOffset;
	}

	@Override
	public char[] getTypeName() {
		return this.typeName;
	}
}