com.sun.jdo.api.persistence.enhancer.classfile.AttributeVector Maven / Gradle / Ivy
/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright (c) 1997-2010 Oracle and/or its affiliates. All rights reserved.
*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common Development
* and Distribution License("CDDL") (collectively, the "License"). You
* may not use this file except in compliance with the License. You can
* obtain a copy of the License at
* https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
* or packager/legal/LICENSE.txt. See the License for the specific
* language governing permissions and limitations under the License.
*
* When distributing the software, include this License Header Notice in each
* file and include the License file at packager/legal/LICENSE.txt.
*
* GPL Classpath Exception:
* Oracle designates this particular file as subject to the "Classpath"
* exception as provided by Oracle in the GPL Version 2 section of the License
* file that accompanied this code.
*
* Modifications:
* If applicable, add the following below the License Header, with the fields
* enclosed by brackets [] replaced by your own identifying information:
* "Portions Copyright [year] [name of copyright owner]"
*
* Contributor(s):
* If you wish your version of this file to be governed by only the CDDL or
* only the GPL Version 2, indicate your decision by adding "[Contributor]
* elects to include this software in this distribution under the [CDDL or GPL
* Version 2] license." If you don't indicate a single choice of license, a
* recipient has the option to distribute your version of this file under
* either the CDDL, the GPL Version 2 or to extend the choice of license to
* its licensees as provided above. However, if you add GPL Version 2 code
* and therefore, elected the GPL Version 2 license, then the option applies
* only if the new code is made subject to such option by the copyright
* holder.
*/
package com.sun.jdo.api.persistence.enhancer.classfile;
import java.io.*;
import java.util.Vector;
import java.util.Enumeration;
import java.util.NoSuchElementException;
/**
* A list of attributes within a class file.
* These lists occur in several places within a class file
* - at class level
* - at method level
* - at field level
* - at attribute level
*/
public class AttributeVector {
/* Vector of ClassAttribute */
private ClassAttribute attributes[] = null;
/**
* Returns the i'th attribute in the array
*/
private ClassAttribute attrAt(int i) {
return attributes[i];
}
/**
* Construct an empty AttributeVector
*/
public AttributeVector() { }
/**
* Add an element to the vector
*/
public void addElement(ClassAttribute attr) {
if (attributes == null)
attributes = new ClassAttribute[1];
else {
ClassAttribute newAttributes[] = new ClassAttribute[attributes.length+1];
System.arraycopy(attributes, 0, newAttributes, 0, attributes.length);
attributes = newAttributes;
}
attributes[attributes.length-1] = attr;
}
public Enumeration elements() {
class AttributeVectorEnumeration implements Enumeration {
private ClassAttribute[] attributes;
private int current = 0;
AttributeVectorEnumeration(ClassAttribute attrs[]) {
attributes = attrs;
}
public boolean hasMoreElements() {
return attributes != null && current < attributes.length;
}
public Object nextElement() {
if (!hasMoreElements())
throw new NoSuchElementException();
return attributes[current++];
}
}
return new AttributeVectorEnumeration(attributes);
}
/**
* Look for an attribute of a specific name
*/
public ClassAttribute findAttribute(String attrName) {
Enumeration e = elements();
while (e.hasMoreElements()) {
ClassAttribute attr = (ClassAttribute) e.nextElement();
if (attr.attrName().asString().equals(attrName))
return attr;
}
return null;
}
/**
* General attribute reader
*/
static AttributeVector readAttributes(
DataInputStream data, ConstantPool constantPool)
throws IOException {
AttributeVector attribs = new AttributeVector();
int n_attrs = data.readUnsignedShort();
while (n_attrs-- > 0) {
attribs.addElement(ClassAttribute.read(data, constantPool));
}
return attribs;
}
/**
* ClassMethod attribute reader
*/
static AttributeVector readAttributes(
DataInputStream data, CodeEnv codeEnv)
throws IOException {
AttributeVector attribs = new AttributeVector();
int n_attrs = data.readUnsignedShort();
while (n_attrs-- > 0) {
attribs.addElement(ClassAttribute.read(data, codeEnv));
}
return attribs;
}
/**
* Write the attributes to the output stream
*/
void write(DataOutputStream out) throws IOException {
if (attributes == null) {
out.writeShort(0);
} else {
out.writeShort(attributes.length);
for (int i=0; i