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/*
* 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.bcel.classfile;
import java.io.DataInput;
import java.io.IOException;
import org.apache.bcel.Const;
import org.apache.bcel.generic.Type;
import org.apache.bcel.util.BCELComparator;
/**
* This class represents the field info structure, i.e., the representation
* for a variable in the class. See JVM specification for details.
*
* @version $Id$
*/
public final class Field extends FieldOrMethod {
private static BCELComparator bcelComparator = new BCELComparator() {
@Override
public boolean equals( final Object o1, final Object o2 ) {
final Field THIS = (Field) o1;
final Field THAT = (Field) o2;
return THIS.getName().equals(THAT.getName())
&& THIS.getSignature().equals(THAT.getSignature());
}
@Override
public int hashCode( final Object o ) {
final Field THIS = (Field) o;
return THIS.getSignature().hashCode() ^ THIS.getName().hashCode();
}
};
/**
* Initialize from another object. Note that both objects use the same
* references (shallow copy). Use clone() for a physical copy.
*/
public Field(final Field c) {
super(c);
}
/**
* Construct object from file stream.
* @param file Input stream
*/
Field(final DataInput file, final ConstantPool constant_pool) throws IOException,
ClassFormatException {
super(file, constant_pool);
}
/**
* @param access_flags Access rights of field
* @param name_index Points to field name in constant pool
* @param signature_index Points to encoded signature
* @param attributes Collection of attributes
* @param constant_pool Array of constants
*/
public Field(final int access_flags, final int name_index, final int signature_index, final Attribute[] attributes,
final ConstantPool constant_pool) {
super(access_flags, name_index, signature_index, attributes, constant_pool);
}
/**
* Called by objects that are traversing the nodes of the tree implicitely
* defined by the contents of a Java class. I.e., the hierarchy of methods,
* fields, attributes, etc. spawns a tree of objects.
*
* @param v Visitor object
*/
@Override
public void accept( final Visitor v ) {
v.visitField(this);
}
/**
* @return constant value associated with this field (may be null)
*/
public final ConstantValue getConstantValue() {
for (final Attribute attribute : super.getAttributes()) {
if (attribute.getTag() == Const.ATTR_CONSTANT_VALUE) {
return (ConstantValue) attribute;
}
}
return null;
}
/**
* Return string representation close to declaration format,
* `public static final short MAX = 100', e.g..
*
* @return String representation of field, including the signature.
*/
@Override
public final String toString() {
String name;
String signature;
String access; // Short cuts to constant pool
// Get names from constant pool
access = Utility.accessToString(super.getAccessFlags());
access = access.isEmpty() ? "" : (access + " ");
signature = Utility.signatureToString(getSignature());
name = getName();
final StringBuilder buf = new StringBuilder(64); // CHECKSTYLE IGNORE MagicNumber
buf.append(access).append(signature).append(" ").append(name);
final ConstantValue cv = getConstantValue();
if (cv != null) {
buf.append(" = ").append(cv);
}
for (final Attribute attribute : super.getAttributes()) {
if (!(attribute instanceof ConstantValue)) {
buf.append(" [").append(attribute).append("]");
}
}
return buf.toString();
}
/**
* @return deep copy of this field
*/
public final Field copy( final ConstantPool _constant_pool ) {
return (Field) copy_(_constant_pool);
}
/**
* @return type of field
*/
public Type getType() {
return Type.getReturnType(getSignature());
}
/**
* @return Comparison strategy object
*/
public static BCELComparator getComparator() {
return bcelComparator;
}
/**
* @param comparator Comparison strategy object
*/
public static void setComparator( final BCELComparator comparator ) {
bcelComparator = comparator;
}
/**
* Return value as defined by given BCELComparator strategy.
* By default two Field objects are said to be equal when
* their names and signatures are equal.
*
* @see java.lang.Object#equals(java.lang.Object)
*/
@Override
public boolean equals( final Object obj ) {
return bcelComparator.equals(this, obj);
}
/**
* Return value as defined by given BCELComparator strategy.
* By default return the hashcode of the field's name XOR signature.
*
* @see java.lang.Object#hashCode()
*/
@Override
public int hashCode() {
return bcelComparator.hashCode(this);
}
}
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