On 16.04.2016 19:16, Uwe Schindler wrote:
Hi,
You can still get a InputStream to bytecode of JDK-internal classes: if you get
the module of the Class and then call getResourceAsStream from there. I walked
that route for the forbidden-apis checker with reflection: This tool needs the
bytecode of runtime classes!
it is a bigger rewrite, but possible to do, yes.... well... anything but
the module part. Right now I am only trying to get my tests working, not
to make a module. And all the jars I am using are no modules either...
so everything comes in from the classpath atm. The only modules involved
are the ones from java itself. And for this part I don´t need the
bytecode of those... right now that is only for the unit tests of a part
that gets a proper configuration when normally used.
Code that loads bytecode of classes of the runtime with reflection:
https://github.com/policeman-tools/forbidden-apis/blob/master/src/main/java/de/thetaphi/forbiddenapis/Checker.java#L223-L252
thanks, I will keep that in mind.
This is the reflective initialization part (to detect pre-Java 9, Java 9
without Jigsaw and Java 9 Jigsaw) and setup the 3 different possibilities:
https://github.com/policeman-tools/forbidden-apis/blob/master/src/main/java/de/thetaphi/forbiddenapis/Checker.java#L132-L198
/please note, forbiddenapis also wants to know which classes of a classloader
come from runtime and which are outside). So it also looks into module name
(starts with java.* Or jdk.*) or if it comes from rt.jar (pre-Java 9). So code
is more complicated than needed for your usecase.
Unfortunately this is fine for tools like forbiddenapis that run in your build
system like Maven or Gradle, but fails horrible with certain security manager
configs. Maybe it is still helpful.
yeah, I am aware of that. I don´t intend to support runtime compilation
with reading from jars in those environments. We can produce a ClassNode
(which I need to compile Groovy classes) in two ways. One is by using
ASM to get the signatures, the other to load using reflective
information. The later one is the oldest version and cannot do as well
as other versions because you cannot get annotation constants without
initializing the class in all cases. Also the ASM version is actually
faster and can deal with classes, consisting of only the signatures
(which can be inspected by javac, but not loaded by reflection).
bye Jochen
