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package com.sun.org.apache.bcel.internal.classfile;


import  com.sun.org.apache.bcel.internal.Constants;
import  java.io.*;

This class is derived from Attribute and represents a reference to a GJ attribute.
Author: M. Dahm
See Also:
/** * This class is derived from <em>Attribute</em> and represents a reference * to a <href="http://wwwipd.ira.uka.de/~pizza/gj/">GJ</a> attribute. * * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A> * @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.
/** * Initialize from another object. Note that both objects use the same * references (shallow copy). Use clone() for a physical copy. */
public Signature(Signature c) { this(c.getNameIndex(), c.getLength(), c.getSignatureIndex(), c.getConstantPool()); }
Construct object from file stream.
Params:
  • name_index – Index in constant pool to CONSTANT_Utf8
  • length – Content length in bytes
  • file – Input stream
  • constant_pool – Array of constants
Throws:
/** * Construct object from file stream. * @param name_index Index in constant pool to CONSTANT_Utf8 * @param length Content length in bytes * @param file Input stream * @param constant_pool Array of constants * @throws IOException */
Signature(int name_index, int length, DataInputStream file, ConstantPool constant_pool) throws IOException { this(name_index, length, file.readUnsignedShort(), constant_pool); }
Params:
  • name_index – Index in constant pool to CONSTANT_Utf8
  • length – Content length in bytes
  • constant_pool – Array of constants
  • Signature_index – Index in constant pool to CONSTANT_Utf8
/** * @param name_index Index in constant pool to CONSTANT_Utf8 * @param length Content length in bytes * @param constant_pool Array of constants * @param Signature_index Index in constant pool to CONSTANT_Utf8 */
public Signature(int name_index, int length, int signature_index, ConstantPool constant_pool) { super(Constants.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.
Params:
  • v – Visitor object
/** * 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 */
public void accept(Visitor v) { System.err.println("Visiting non-standard Signature object"); v.visitSignature(this); }
Dump source file attribute to file stream in binary format.
Params:
  • file – Output file stream
Throws:
/** * Dump source file attribute to file stream in binary format. * * @param file Output file stream * @throws IOException */
public final void dump(DataOutputStream file) throws IOException { super.dump(file); file.writeShort(signature_index); }
Returns:Index in constant pool of source file name.
/** * @return Index in constant pool of source file name. */
public final int getSignatureIndex() { return signature_index; }
@paramSignature_index.
/** * @param Signature_index. */
public final void setSignatureIndex(int signature_index) { this.signature_index = signature_index; }
Returns:GJ signature.
/** * @return GJ signature. */
public final String getSignature() { ConstantUtf8 c = (ConstantUtf8)constant_pool.getConstant(signature_index, Constants.CONSTANT_Utf8); return c.getBytes(); }
Extends ByteArrayInputStream to make 'unreading' chars possible.
/** * Extends ByteArrayInputStream to make 'unreading' chars possible. */
private static final class MyByteArrayInputStream extends ByteArrayInputStream { MyByteArrayInputStream(String data) { super(data.getBytes()); } final int mark() { return pos; } final String getData() { return new String(buf); } final void reset(int p) { pos = p; } final void unread() { if(pos > 0) pos--; } } private static boolean identStart(int ch) { return ch == 'T' || ch == 'L'; } private static boolean identPart(int ch) { return ch == '/' || ch == ';'; } private static final void matchIdent(MyByteArrayInputStream in, StringBuffer 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)) { StringBuffer buf2 = new StringBuffer(); 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; } StringBuffer buf2 = new StringBuffer(); 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 final void matchGJIdent(MyByteArrayInputStream in, StringBuffer 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(String s) { //System.out.println("Sig:" + s); StringBuffer buf = new StringBuffer(); matchGJIdent(new MyByteArrayInputStream(s), buf); return buf.toString(); } public static final boolean isFormalParameterList(String s) { return s.startsWith("<") && (s.indexOf(':') > 0); } public static final boolean isActualParameterList(String s) { return s.startsWith("L") && s.endsWith(">;"); }
Returns:String representation
/** * @return String representation */
public final String toString() { String s = getSignature(); return "Signature(" + s + ")"; }
Returns:deep copy of this attribute
/** * @return deep copy of this attribute */
public Attribute copy(ConstantPool constant_pool) { return (Signature)clone(); } }