Member Avatar for stevanity

I wanted to know how Java does Object Cloning. But when I read the Object.java class I saw that it was not defined in it. Im confused. I really dont know who internals of java are implemented. It would be nice if someone could help me with this.....

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Member Avatar for nmaillet 
protected native Object clone() throws CloneNotSupportedException;

Notice the native keyword. This means that the method is not implemented using Java, but using native code (C/C++) using the Java Native Interface (http://java.sun.com/docs/books/jni/).

Edited by nmaillet because: n/a
Member Avatar for NormR1

What doc are you getting that from?
My API doc has this:
protected Object clone()

Member Avatar for nmaillet

The API doc does say protected Object clone() yes. The source code, shows it with the native keyword.

Member Avatar for NormR1

How many other methods are native? I'll bet a lot.

Member Avatar for peter_budo

What doc are you getting that from?
My API doc has this:
protected Object clone()

Just open the class in IDE and get source (that is how it does work in IntelliJ), then you can see internal structure :)

Edited by peter_budo because: n/a
Member Avatar for ~s.o.s~

Adding on to others, it also pays to know that cloning in Java is pretty much broken and for practical purposes you are better off using other alternatives (hand rolled copy constructor).

Member Avatar for stevanity

OH Thankyou. What if I wanted to see the native code for Cloning?

Member Avatar for JamesCherrill

There's a load of non-Java-language stuff in the source code download, including C code. I haven't looked at that, but you may find it there?

Member Avatar for stevanity

Oh Thank you. My first guess would be that it would make a memory copy. But Ill try to lookup the source code to see if I can find stuff..

Thanks DW team!!!!

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