4 Replies Latest reply on Dec 15, 2014 7:28 PM by enielsen

$proceed($$) for private methods

aarontdixon Jun 9, 2012 7:44 PM

I get a compile error when Javassist is trying to compile a method replacement when the method is private.

method.instrument(new ExprEditor() {

public void edit(MethodCall m) throws CannotCompileException {

m.replace("$_ = $proceed($$);");

}

Is there a way I can get Javassist to compile invocations of private methods?

1. Re: $proceed($$) for private methods

aarontdixon Jun 9, 2012 7:59 PM (in response to aarontdixon)

Clarification:

Javassist fails when the private method that is invoked is *static private*.

Is this a defect?
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2. Re: $proceed($$) for private methods

settimer Jan 31, 2013 6:44 PM (in response to aarontdixon)

I encoutered the same issue. Have you figured it out?

Below is a mored detailed description:

I try to instrument the call in the method:

    public static Currency getInstance(String currencyCode) {
        return getInstance(currencyCode, Integer.MIN_VALUE);
    }

, which is inside java/util/Currency.class. The call invokes "private static Currency getInstance(String, int)", which is enclosed in the same class as the caller.

I need to add some statements around the call "getInstance(currencyCode, Integer.MIN_VALUE);". So I used MethodCall.replace("{some statements; $_ = $proceed($$); other statements;}"), then I got the exception like below:

Caused by: compile error: Method getInstance is private
    at javassist.compiler.
MemberCodeGen.getAccessiblePrivate(MemberCodeGen.java:671)
    at javassist.compiler.MemberCodeGen.atMethodCallCore2(MemberCodeGen.java:612)
     at javassist.compiler.MemberCodeGen.atMethodCallCore(MemberCodeGen.java:575)
    at javassist.compiler.MemberCodeGen.atCallExpr(MemberCodeGen.java:523)
    at javassist.compiler.JvstCodeGen.atCallExpr(JvstCodeGen.java:244)
     at javassist.compiler.ast.CallExpr.accept(CallExpr.java:46)
    at javassist.compiler.CodeGen.compileExpr(CodeGen.java:230)
    at javassist.compiler.Javac$2.doit(Javac.java:490)
    at javassist.compiler.JvstCodeGen.atCallExpr(JvstCodeGen.java:235)
     at javassist.compiler.ast.CallExpr.accept(CallExpr.java:46)
    at javassist.compiler.CodeGen.atAssignCore(CodeGen.java:860)
    at javassist.compiler.CodeGen.atVariableAssign(CodeGen.java:793)
    at javassist.compiler.CodeGen.atAssignExpr(CodeGen.java:747)
     at javassist.compiler.CodeGen.atStmnt(CodeGen.java:332)
    at javassist.compiler.ast.Stmnt.accept(Stmnt.java:50)
    at javassist.compiler.CodeGen.atStmnt(CodeGen.java:351)
    at javassist.compiler.ast.Stmnt.accept(Stmnt.java:50)
     at javassist.compiler.Javac.compileStmnt(Javac.java:569)
    at javassist.expr.MethodCall.replace(MethodCall.java:235)
    ... 18 more

The bug can be reproduced. For example, in java.lang.securityManager, the method checkPackageAccess contains a call
"packageAccess = getPackages(tmpPropertyStr);", The call invokes "private static String[] getPackages(String p)".

In both cases, it involves invocations to "private static" methods.
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3. Re: $proceed($$) for private methods

yanic Feb 28, 2013 11:00 AM (in response to settimer)

I had the same issue, please post the code fragment where you call makeClass on the ClassPool so I can check if it's the same case.
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4. Re: $proceed($$) for private methods

enielsen Dec 15, 2014 7:28 PM (in response to aarontdixon)

I was having the same problem. In my case I was trying to call a private method in a superclass, which is of couse impossible to do!
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