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Apache Commons Bytecode Engineering Library, with type annotations
The newest version!
/*
* 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;
/*>>>
import org.checkerframework.checker.nullness.qual.Nullable;
import org.checkerframework.framework.qual.AnnotatedFor;
*/
/**
* This class represents the method info structure, i.e., the representation
* for a method in the class. See JVM specification for details.
* A method has access flags, a name, a signature and a number of attributes.
*
* @version $Id$
*/
/*@AnnotatedFor({"nullness"})*/
public final class Method extends FieldOrMethod {
private static BCELComparator bcelComparator = new BCELComparator() {
@Override
public boolean equals( final Object o1, final Object o2 ) {
final Method THIS = (Method) o1;
final Method THAT = (Method) o2;
return THIS.getName().equals(THAT.getName())
&& THIS.getSignature().equals(THAT.getSignature());
}
@Override
public int hashCode( final Object o ) {
final Method THIS = (Method) o;
return THIS.getSignature().hashCode() ^ THIS.getName().hashCode();
}
};
// annotations defined on the parameters of a method
private ParameterAnnotationEntry[] parameterAnnotationEntries;
/**
* Empty constructor, all attributes have to be defined via `setXXX'
* methods. Use at your own risk.
*/
public Method() {
}
/**
* Initialize from another object. Note that both objects use the same
* references (shallow copy). Use clone() for a physical copy.
*/
public Method(final Method c) {
super(c);
}
/**
* Construct object from file stream.
* @param file Input stream
* @throws IOException
* @throws ClassFormatException
*/
Method(final DataInput file, final ConstantPool constant_pool) throws IOException,
ClassFormatException {
super(file, constant_pool);
}
/**
* @param access_flags Access rights of method
* @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 Method(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.visitMethod(this);
}
/**
* @return Code attribute of method, if any
*/
public final /*@Nullable*/ Code getCode() {
for (final Attribute attribute : super.getAttributes()) {
if (attribute instanceof Code) {
return (Code) attribute;
}
}
return null;
}
/**
* @return ExceptionTable attribute of method, if any, i.e., list all
* exceptions the method may throw not exception handlers!
*/
public final /*@Nullable*/ ExceptionTable getExceptionTable() {
for (final Attribute attribute : super.getAttributes()) {
if (attribute instanceof ExceptionTable) {
return (ExceptionTable) attribute;
}
}
return null;
}
/** @return LocalVariableTable of code attribute if any, i.e. the call is forwarded
* to the Code atribute.
*/
public final /*@Nullable*/ LocalVariableTable getLocalVariableTable() {
final Code code = getCode();
if (code == null) {
return null;
}
return code.getLocalVariableTable();
}
/** @return LineNumberTable of code attribute if any, i.e. the call is forwarded
* to the Code atribute.
*/
public final /*@Nullable*/ LineNumberTable getLineNumberTable() {
final Code code = getCode();
if (code == null) {
return null;
}
return code.getLineNumberTable();
}
/**
* Return string representation close to declaration format,
* `public static void main(String[] args) throws IOException', e.g.
*
* @return String representation of the method.
*/
@Override
public final String toString() {
final String access = Utility.accessToString(super.getAccessFlags());
// Get name and signature from constant pool
ConstantUtf8 c = (ConstantUtf8) super.getConstantPool().getConstant(super.getSignatureIndex(), Const.CONSTANT_Utf8);
String signature = c.getBytes();
c = (ConstantUtf8) super.getConstantPool().getConstant(super.getNameIndex(), Const.CONSTANT_Utf8);
final String name = c.getBytes();
signature = Utility.methodSignatureToString(signature, name, access, true,
getLocalVariableTable());
final StringBuilder buf = new StringBuilder(signature);
for (final Attribute attribute : super.getAttributes()) {
if (!((attribute instanceof Code) || (attribute instanceof ExceptionTable))) {
buf.append(" [").append(attribute).append("]");
}
}
final ExceptionTable e = getExceptionTable();
if (e != null) {
final String str = e.toString();
if (!str.isEmpty()) {
buf.append("\n\t\tthrows ").append(str);
}
}
return buf.toString();
}
/**
* @return deep copy of this method
*/
public final Method copy( final ConstantPool _constant_pool ) {
return (Method) copy_(_constant_pool);
}
/**
* @return return type of method
*/
public Type getReturnType() {
return Type.getReturnType(getSignature());
}
/**
* @return array of method argument types
*/
public Type[] getArgumentTypes() {
return Type.getArgumentTypes(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 method 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 /*@Nullable*/ Object obj ) {
return bcelComparator.equals(this, obj);
}
/**
* Return value as defined by given BCELComparator strategy.
* By default return the hashcode of the method's name XOR signature.
*
* @see java.lang.Object#hashCode()
*/
@Override
public int hashCode() {
return bcelComparator.hashCode(this);
}
/**
* @return Annotations on the parameters of a method
* @since 6.0
*/
public ParameterAnnotationEntry[] getParameterAnnotationEntries() {
if (parameterAnnotationEntries == null) {
parameterAnnotationEntries = ParameterAnnotationEntry.createParameterAnnotationEntries(getAttributes());
}
return parameterAnnotationEntries;
}
}