org.apache.bcel.classfile.Signature Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of commons-bcel Show documentation
Show all versions of commons-bcel Show documentation
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.ByteArrayInputStream;
import java.io.DataInput;
import java.io.DataOutputStream;
import java.io.IOException;
import org.apache.bcel.Const;
/**
* This class is derived from Attribute and represents a reference
* to a GJ attribute.
*
* @version $Id$
* @see Attribute
*/
public final class Signature extends Attribute {
private int signature_index;
/**
* Initialize from another object. Note that both objects use the same
* references (shallow copy). Use clone() for a physical copy.
*/
public Signature(final Signature c) {
this(c.getNameIndex(), c.getLength(), c.getSignatureIndex(), c.getConstantPool());
}
/**
* Construct object from file stream.
* @param name_index Index in constant pool to CONSTANT_Utf8
* @param length Content length in bytes
* @param input Input stream
* @param constant_pool Array of constants
* @throws IOException
*/
Signature(final int name_index, final int length, final DataInput input, final ConstantPool constant_pool)
throws IOException {
this(name_index, length, input.readUnsignedShort(), constant_pool);
}
/**
* @param name_index Index in constant pool to CONSTANT_Utf8
* @param length Content length in bytes
* @param signature_index Index in constant pool to CONSTANT_Utf8
* @param constant_pool Array of constants
*/
public Signature(final int name_index, final int length, final int signature_index, final ConstantPool constant_pool) {
super(Const.ATTR_SIGNATURE, name_index, length, constant_pool);
this.signature_index = signature_index;
}
/**
* 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 ) {
//System.err.println("Visiting non-standard Signature object");
v.visitSignature(this);
}
/**
* Dump source file attribute to file stream in binary format.
*
* @param file Output file stream
* @throws IOException
*/
@Override
public final void dump( final DataOutputStream file ) throws IOException {
super.dump(file);
file.writeShort(signature_index);
}
/**
* @return Index in constant pool of source file name.
*/
public final int getSignatureIndex() {
return signature_index;
}
/**
* @param signature_index the index info the constant pool of this signature
*/
public final void setSignatureIndex( final int signature_index ) {
this.signature_index = signature_index;
}
/**
* @return GJ signature.
*/
public final String getSignature() {
final ConstantUtf8 c = (ConstantUtf8) super.getConstantPool().getConstant(signature_index,
Const.CONSTANT_Utf8);
return c.getBytes();
}
/**
* Extends ByteArrayInputStream to make 'unreading' chars possible.
*/
private static final class MyByteArrayInputStream extends ByteArrayInputStream {
MyByteArrayInputStream(final String data) {
super(data.getBytes());
}
final String getData() {
return new String(buf);
}
final void unread() {
if (pos > 0) {
pos--;
}
}
}
private static boolean identStart( final int ch ) {
return ch == 'T' || ch == 'L';
}
private static void matchIdent( final MyByteArrayInputStream in, final StringBuilder buf ) {
int ch;
if ((ch = in.read()) == -1) {
throw new RuntimeException("Illegal signature: " + in.getData()
+ " no ident, reaching EOF");
}
//System.out.println("return from ident:" + (char)ch);
if (!identStart(ch)) {
final StringBuilder buf2 = new StringBuilder();
int count = 1;
while (Character.isJavaIdentifierPart((char) ch)) {
buf2.append((char) ch);
count++;
ch = in.read();
}
if (ch == ':') { // Ok, formal parameter
in.skip("Ljava/lang/Object".length());
buf.append(buf2);
ch = in.read();
in.unread();
//System.out.println("so far:" + buf2 + ":next:" +(char)ch);
} else {
for (int i = 0; i < count; i++) {
in.unread();
}
}
return;
}
final StringBuilder buf2 = new StringBuilder();
ch = in.read();
do {
buf2.append((char) ch);
ch = in.read();
//System.out.println("within ident:"+ (char)ch);
} while ((ch != -1) && (Character.isJavaIdentifierPart((char) ch) || (ch == '/')));
buf.append(buf2.toString().replace('/', '.'));
//System.out.println("regular return ident:"+ (char)ch + ":" + buf2);
if (ch != -1) {
in.unread();
}
}
private static void matchGJIdent( final MyByteArrayInputStream in, final StringBuilder buf ) {
int ch;
matchIdent(in, buf);
ch = in.read();
if ((ch == '<') || ch == '(') { // Parameterized or method
//System.out.println("Enter <");
buf.append((char) ch);
matchGJIdent(in, buf);
while (((ch = in.read()) != '>') && (ch != ')')) { // List of parameters
if (ch == -1) {
throw new RuntimeException("Illegal signature: " + in.getData()
+ " reaching EOF");
}
//System.out.println("Still no >");
buf.append(", ");
in.unread();
matchGJIdent(in, buf); // Recursive call
}
//System.out.println("Exit >");
buf.append((char) ch);
} else {
in.unread();
}
ch = in.read();
if (identStart(ch)) {
in.unread();
matchGJIdent(in, buf);
} else if (ch == ')') {
in.unread();
return;
} else if (ch != ';') {
throw new RuntimeException("Illegal signature: " + in.getData() + " read " + (char) ch);
}
}
public static String translate( final String s ) {
//System.out.println("Sig:" + s);
final StringBuilder buf = new StringBuilder();
matchGJIdent(new MyByteArrayInputStream(s), buf);
return buf.toString();
}
// @since 6.0 is no longer final
public static boolean isFormalParameterList( final String s ) {
return s.startsWith("<") && (s.indexOf(':') > 0);
}
// @since 6.0 is no longer final
public static boolean isActualParameterList( final String s ) {
return s.startsWith("L") && s.endsWith(">;");
}
/**
* @return String representation
*/
@Override
public final String toString() {
final String s = getSignature();
return "Signature: " + s;
}
/**
* @return deep copy of this attribute
*/
@Override
public Attribute copy( final ConstantPool _constant_pool ) {
return (Attribute) clone();
}
}