oracle.toplink.libraries.asm.attrs
Class SignatureAttribute

java.lang.Object
  oracle.toplink.libraries.asm.Attribute
      oracle.toplink.libraries.asm.attrs.SignatureAttribute

Direct Known Subclasses:

ASMSignatureAttribute

public class SignatureAttribute
extends Attribute

The Signature Attribute introduced in JSR-14 (Adding Generics to the Java Programming Language) and also defined in the Java Virtual Machine Specification, 3rd edition draft. This atribute is used for classes, fields and methods.

Classfiles need to carry generic type information in a backwards compatible way. This is accomplished by introducing a new "Signature" attribute for classes, methods and fields. The structure of this attribute is as follows:

   "Signature" (u4 attr-length, u2 signature-index)
 

When used as an attribute of a method or field, a signature gives the full (possibly generic) type of that method or field. When used as a class attribute, a signature indicates the type parameters of the class, followed by its supertype, followed by all its interfaces.

The type syntax in signatures is extended to parameterized types and type variables. There is also a new signature syntax for formal type parameters. The syntax extensions for signature strings are as follows:

   MethodOrFieldSignature ::= TypeSignature
   ClassSignature        ::= ParameterPartOpt super_TypeSignature interface_TypeSignatures
   TypeSignatures        ::= TypeSignatures TypeSignature
                             |
   TypeSignature         ::= ...
                             | ClassTypeSignature
                             | MethodTypeSignature
                             | TypeVariableSignature
   ClassTypeSignature    ::= 'L' Ident TypeArgumentsOpt ';'
                             | ClassTypeSignature '.' Ident ';' TypeArgumentsOpt
   MethodTypeSignature   ::= TypeArgumentsOpt '(' TypeSignatures ')'
                             TypeSignature ThrowsSignatureListOpt
   ThrowsSignatureList   ::= ThrowsSignature ThrowsSignatureList
                             | ThrowsSignature
   ThrowsSignature       ::= '^' TypeSignature
   TypeVariableSignature ::= 'T' Ident ';'
   TypeArguments         ::= '<' TypeSignature TypeSignatures '>'
   ParameterPart         ::= '<' ParameterSignature ParameterSignatures '>'
   ParameterSignatures   ::= ParameterSignatures ParameterSignature
                             |
   ParameterSignature ::= Ident ':' bound_TypeSignature
 

See Also:

JSR 14 : Add Generic Types To The JavaTM Programming Language

Field Summary

java.lang.String

signature

Fields inherited from class oracle.toplink.libraries.asm.Attribute

next, type

Constructor Summary

SignatureAttribute()

SignatureAttribute(java.lang.String signature)

Method Summary

java.lang.String

toString()

Methods inherited from class oracle.toplink.libraries.asm.Attribute

isUnknown

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

signature

public java.lang.String signature

Constructor Detail

SignatureAttribute

public SignatureAttribute()

SignatureAttribute

public SignatureAttribute(java.lang.String signature)

Method Detail

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object