How does setOut method change the value of System.out which is final in System class

Question

Possible Duplicate:
java: “final” System.out?

Can someone please help me in understanding how the setOut method works?
It can change the current pipe lining of System.out from Monitor to PrintStream object, but how is it changing reference of out?

score 2 · Answer 1 · answered Jun 29 '11 at 11:52

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System#setOut internally calls a native method to redirect out. In other words: voodoo magic ;)

answered Jun 29 '11 at 11:52

Andreas Dolk

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Well done Can you please explain some more about voodoo magic and how setOut use it. – VikasGoyal Nov 14 '14 at 02:49

score 0 · Answer 2 · answered Jun 29 '11 at 11:54

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Since Java is open source, let's have a look:

http://www.mavenjava.com/sun/jdk/1.6.0/src/java/lang/System.java.html#System.setOut%28java.io.PrintStream%29

It calls out to a native method to set the output - the JVM basically bypasses the "final" check.

answered Jun 29 '11 at 11:54

Paolo

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Paolo how can u prove that what u saying is right??? i mean do u have reasons to ur answer. – Saurabh Gupta Jun 29 '11 at 12:17
See the accepted answer in the duplicate question link – Paolo Jun 29 '11 at 12:25

How does setOut method change the value of System.out which is final in System class

2 Answers2