CODEWITHSUNDEEP
javaclassloader
AKS
AKS

Reputation: 1423

Class loading by bootstrapclassloader

Here is what I was asked in interview:

If a new method is added to String class and compiled and put in rt.jar, then will bootstrap class loader load it?

I answered that it will not get loaded but could not tell why.

Please help me with correct answer and explanation of that.

Upvotes: 0

Views: 167

Answers (1)

Joachim Sauer
Joachim Sauer

Reputation: 308001

It will be loaded.

And not just that: it need not even be in rt.jar, if you prepend a jar file to the boot-classpath (see -Xbootclasspath/p:path), then you can even load java.lang.* classes from other jar files.

This of course is a way to violate the security of the JVM, but you need pretty deep access (either write-access to rt.jar or access to the command line parameters of the JVM) and when you have those, you can do a lot more than just replace String.toString().

Upvotes: 1

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