JDK5 Features - RetroGuard Documentation
Annotations (JDK5/1.5 Metadata)
Java now supports class, method, and field metadata; this is described
in the Annotations guide at Sun, and in JSR 175 at the Java Community Process.
At the classfile level, these annotations are encoded as attributes named
RuntimeVisibleAnnotations,
RuntimeInvisibleAnnotations,
RuntimeVisibleParameterAnnotations,
RuntimeInvisibleParameterAnnotations,
and AnnotationDefault.
To preserve only the run-time accessible annotations, add a script line:
.option RuntimeAnnotations
This is exactly equivalent to the script lines:
.attribute RuntimeVisibleAnnotations
.attribute RuntimeVisibleParameterAnnotations
.attribute AnnotationDefault
To preserve all annotations, add a script line:
.option Annotations
This is exactly equivalent to the script lines:
.attribute RuntimeInvisibleAnnotations
.attribute RuntimeInvisibleParameterAnnotations
.attribute RuntimeVisibleAnnotations
.attribute RuntimeVisibleParameterAnnotations
.attribute AnnotationDefault
Enumerations (JDK5/1.5 'enum')
Java now supports typesafe enums; this is described in the
Enums guide
at Sun, and as part of JSR 201 at the Java Community Process.
Enumerations will work normally after obfuscation with no special effort.
However, if you intend to access the enumerations later from outside the
obfuscated jar, use the script line:
.option Enumeration
This is exactly equivalent to the script line:
.class ** public extends java/lang/Enum
To preserve a particular enum, use the script line:
.class com/widgetco/MyEnum public extends java/lang/Enum
RetroGuard
always preserves the auto-generated static methods values()
and valueOf(...) in enumerations. This is necessary to ensure
enumerations work correctly after obfuscation.
Generics (JDK5/1.5)
Java now supports parametric polymorphism, or generic types; this is described in the
Generics guide
at Sun, in JSR 14 at the Java Community Process, and in the article
Using and Programming Generics.
Generics will work normally after obfuscation with no special effort.
However, if you intend to compile other classes against your obfuscated code
or use reflection to determine generic types, the attribute
Signature should be preserved.
The classfile attribute Signature contains generic
type information used during reflection by the class
java.lang.Class and classes in the package
java.lang.reflect. To preserve signature information
about generic types during obfuscation, use the script line:
.attribute Signature
[RetroGuard-v2.2.x only]
or the equivalent option:
.option Generic
When debugging information has been generated for a class using the
javac -g compiler option and local variables in the
Java source have generic types, the attribute
LocalVariableTypeTable will
appear in the Code attributes of those methods.
To preserve local variable generic type information during
obfuscation, use the script line:
.attribute LocalVariableTypeTable
The type signatures within the Signature and
LocalVariableTypeTable attributes are
not currently updated by RetroGuard into their obfuscated versions. So, for
these attributes' content to be meaningful, you must also preserve from
obfuscation any Java identifiers that are referenced in type signatures.
EnclosingMethod (JDK5/1.5)
To provide additional information about inner classes, the attribute
EnclosingMethod has been added to Java. This can be preserved during obfuscation using the script line:
.attribute EnclosingMethod
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