org.apache.tomcat.util.bcel.classfile.Field 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.io.DataInputStream;
import java.io.IOException;
import org.apache.tomcat.util.bcel.Constants;
import org.apache.tomcat.util.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: Field.java 1181133 2011-10-10 18:49:14Z markt $
* @author M. Dahm
*/
public final class Field extends FieldOrMethod {
private static final long serialVersionUID = 2646214544240375238L;
private static BCELComparator _cmp = new BCELComparator() {
@Override
public boolean equals( Object o1, Object o2 ) {
Field THIS = (Field) o1;
Field THAT = (Field) o2;
return THIS.getName().equals(THAT.getName())
&& THIS.getSignature().equals(THAT.getSignature());
}
@Override
public int hashCode( Object o ) {
Field THIS = (Field) o;
return THIS.getSignature().hashCode() ^ THIS.getName().hashCode();
}
};
/**
* Construct object from file stream.
* @param file Input stream
*/
Field(DataInputStream file, ConstantPool constant_pool) throws IOException,
ClassFormatException {
super(file, constant_pool);
}
/**
* @return constant value associated with this field (may be null)
*/
public final ConstantValue getConstantValue() {
for (int i = 0; i < attributes_count; i++) {
if (attributes[i].getTag() == Constants.ATTR_CONSTANT_VALUE) {
return (ConstantValue) attributes[i];
}
}
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, signature, access; // Short cuts to constant pool
// Get names from constant pool
access = Utility.accessToString(access_flags);
access = access.equals("") ? "" : (access + " ");
signature = Utility.signatureToString(getSignature());
name = getName();
StringBuilder buf = new StringBuilder(64);
buf.append(access).append(signature).append(" ").append(name);
ConstantValue cv = getConstantValue();
if (cv != null) {
buf.append(" = ").append(cv);
}
for (int i = 0; i < attributes_count; i++) {
Attribute a = attributes[i];
if (!(a instanceof ConstantValue)) {
buf.append(" [").append(a.toString()).append("]");
}
}
return buf.toString();
}
/**
* 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( Object obj ) {
return _cmp.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 _cmp.hashCode(this);
}
}