org.apache.tomcat.util.bcel.classfile.JavaClass Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package org.apache.tomcat.util.bcel.classfile;
import java.util.ArrayList;
import java.util.List;
import org.apache.tomcat.util.bcel.Constants;
import org.apache.tomcat.util.bcel.util.BCELComparator;
/**
* Represents a Java class, i.e., the data structures, constant pool,
* fields, methods and commands contained in a Java .class file.
* See JVM specification for details.
* The intent of this class is to represent a parsed or otherwise existing
* class file. Those interested in programatically generating classes
* should see the ClassGen class.
* @author M. Dahm
*/
public class JavaClass extends AccessFlags
implements Cloneable, Comparable {
private static final long serialVersionUID = 7029227708237523236L;
private String class_name;
private String superclass_name;
private String[] interface_names;
private Attribute[] attributes; // attributes defined in the class
private AnnotationEntry[] annotations; // annotations defined on the class
// Annotations are collected from certain attributes, don't do it more than necessary!
private boolean annotationsOutOfDate = true;
private static BCELComparator _cmp = new BCELComparator() {
@Override
public boolean equals( Object o1, Object o2 ) {
JavaClass THIS = (JavaClass) o1;
JavaClass THAT = (JavaClass) o2;
return THIS.getClassName().equals(THAT.getClassName());
}
@Override
public int hashCode( Object o ) {
JavaClass THIS = (JavaClass) o;
return THIS.getClassName().hashCode();
}
};
/**
* Constructor gets all contents as arguments.
*
* @param class_name_index Index into constant pool referencing a
* ConstantClass that represents this class.
* @param superclass_name_index Index into constant pool referencing a
* ConstantClass that represents this class's superclass.
* @param access_flags Access rights defined by bit flags
* @param constant_pool Array of constants
* @param interfaces Implemented interfaces
* @param attributes Class attributes
*/
public JavaClass(int class_name_index, int superclass_name_index,
int access_flags, ConstantPool constant_pool, int[] interfaces,
Attribute[] attributes) {
if (interfaces == null) {
interfaces = new int[0];
}
if (attributes == null) {
attributes = new Attribute[0];
}
this.access_flags = access_flags;
this.attributes = attributes;
annotationsOutOfDate = true;
/* According to the specification the following entries must be of type
* `ConstantClass' but we check that anyway via the
* `ConstPool.getConstant' method.
*/
class_name = constant_pool.getConstantString(class_name_index, Constants.CONSTANT_Class);
class_name = Utility.compactClassName(class_name);
if (superclass_name_index > 0) {
// May be zero -> class is java.lang.Object
superclass_name = constant_pool.getConstantString(superclass_name_index,
Constants.CONSTANT_Class);
superclass_name = Utility.compactClassName(superclass_name);
} else {
superclass_name = "java.lang.Object";
}
interface_names = new String[interfaces.length];
for (int i = 0; i < interfaces.length; i++) {
String str = constant_pool.getConstantString(interfaces[i], Constants.CONSTANT_Class);
interface_names[i] = Utility.compactClassName(str);
}
}
public AnnotationEntry[] getAnnotationEntries() {
if (annotationsOutOfDate) {
// Find attributes that contain annotation data
List accumulatedAnnotations = new ArrayList<>();
for (Attribute attribute : attributes) {
if (attribute instanceof Annotations) {
Annotations runtimeAnnotations = (Annotations)attribute;
for(int j = 0; j < runtimeAnnotations.getAnnotationEntries().length; j++)
accumulatedAnnotations.add(runtimeAnnotations.getAnnotationEntries()[j]);
}
}
annotations = accumulatedAnnotations.toArray(new AnnotationEntry[accumulatedAnnotations.size()]);
annotationsOutOfDate = false;
}
return annotations;
}
/**
* @return Class name.
*/
public String getClassName() {
return class_name;
}
/**
* @return Names of implemented interfaces.
*/
public String[] getInterfaceNames() {
return interface_names;
}
/**
* returns the super class name of this class. In the case that this class is
* java.lang.Object, it will return itself (java.lang.Object). This is probably incorrect
* but isn't fixed at this time to not break existing clients.
*
* @return Superclass name.
*/
public String getSuperclassName() {
return superclass_name;
}
/**
* Return value as defined by given BCELComparator strategy.
* By default two JavaClass objects are said to be equal when
* their class names are equal.
*
* @see java.lang.Object#equals(java.lang.Object)
*/
@Override
public boolean equals( Object obj ) {
return _cmp.equals(this, obj);
}
/**
* Return the natural ordering of two JavaClasses.
* This ordering is based on the class name
*/
@Override
public int compareTo(JavaClass obj) {
return getClassName().compareTo(obj.getClassName());
}
/**
* Return value as defined by given BCELComparator strategy.
* By default return the hashcode of the class name.
*
* @see java.lang.Object#hashCode()
*/
@Override
public int hashCode() {
return _cmp.hashCode(this);
}
}