Help in Object.clone()

Hi All,
why i am unable to call the clone() in Object class from the subclass of the Object class.
Obj o1 = new Obj(); //Simple bean class.
o1.clone() //error.error:- the method clone() from the type Object is not visible
note : clone() is protected and native.
Thanks
Dorairaj M
Edited by: DoraiRaj on Apr 13, 2010 9:02 AM

malcolmmc wrote:
dcminter wrote:
I don't see the big problem.No a big problem that I know of - it just didn't offer anything you couldn't do with copy constructors and but did put up minor obstacles as well as adding an unnecessary method to Object.What it does offer is a method to copy the fields of an object all in one go, rather than having to list them or use introspection. A copy constructor wouldn't do that for you. Also you can clone a superclass reference and have all the fields of a subclass still copied. A copy constructor is unlikely to do that.Exactly. That's why I figured clone() might be preferred--the polymorphism more than the all-in-one bit. I guess it depends on your requirements.

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# An unexpected error has been detected by Java Runtime Environment:
# EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x6d8fe397, pid=4680, tid=3752
# Java VM: Java HotSpot(TM) Client VM (11.0-b15 mixed mode windows-x86)
# Problematic frame:
# V [jvm.dll+0xfe397]
--------------- T H R E A D ---------------
Current thread (0x4b8ec800): JavaThread "Precomputing action graphs" [_thread_in_vm, id=3752, stack(0x4e4b0000,0x4e8b0000)]
siginfo: ExceptionCode=0xc0000005, reading address 0x80000068
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(cut)
Top of Stack: (sp=0x4e8af53c)
(cut)
Instructions: (pc=0x6d8fe397)
0x6d8fe387:   eb 0b df 2c c8 df 3c ca 83 e9 01 7d f5 8b 57 04
0x6d8fe397:   8b 42 68 89 45 0c 8b 4d 0c 89 0f 8b 15 34 06 a3
Stack: [0x4e4b0000,0x4e8b0000], sp=0x4e8af53c, free space=4093k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
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J java.lang.Object.clone()Ljava/lang/Object;
J com.fairisaac.....cloneArrayListofShortArray()
j java.lang.Thread.run()V+11
v ~StubRoutines::call_stub
--------------- P R O C E S S ---------------
Java Threads: ( => current thread )
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0x4b804000 JavaThread "Thread-5" [_thread_blocked, id=1488, stack(0x4f200000,0x4f600000)]
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0x4b6d7800 JavaThread "D3D Screen Updater" daemon [_thread_blocked, id=804, stack(0x4c280000,0x4c680000)]
0x4a56f000 JavaThread "AWT-EventQueue-0" [_thread_blocked, id=260, stack(0x4be80000,0x4c280000)]
0x4a513000 JavaThread "TimerQueue" daemon [_thread_blocked, id=5028, stack(0x4ba80000,0x4be80000)]
0x4a447400 JavaThread "AWT-Windows" daemon [_thread_in_native, id=5108, stack(0x4adf0000,0x4b1f0000)]
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0x4a4a6800 JavaThread "Java2D Disposer" daemon [_thread_blocked, id=6108, stack(0x4a5f0000,0x4a9f0000)]
0x48e15c00 JavaThread "Low Memory Detector" daemon [_thread_blocked, id=5896, stack(0x49f20000,0x4a320000)]
0x48e0f800 JavaThread "CompilerThread0" daemon [_thread_blocked, id=4496, stack(0x49ed0000,0x49f20000)]
0x48e0e000 JavaThread "Attach Listener" daemon [_thread_blocked, id=2180, stack(0x49ad0000,0x49ed0000)]
0x48e0cc00 JavaThread "Signal Dispatcher" daemon [_thread_blocked, id=2468, stack(0x496d0000,0x49ad0000)]
0x48dfc800 JavaThread "Finalizer" daemon [_thread_blocked, id=5300, stack(0x492d0000,0x496d0000)]
0x48df7c00 JavaThread "Reference Handler" daemon [_thread_blocked, id=4656, stack(0x48ed0000,0x492d0000)]
Other Threads:
0x48df2c00 VMThread [stack: 0x48e80000,0x48ed0000] [id=1776]
0x48e20000 WatcherThread [stack: 0x4a320000,0x4a370000] [id=4820]
VM state:not at safepoint (normal execution)
VM Mutex/Monitor currently owned by a thread: None
Heap
def new generation   total 72576K, used 40121K [0x02d40000, 0x07c00000, 0x07c00000)
eden space 64512K, 50% used [0x02d40000, 0x04d38588, 0x06c40000)
from space 8064K, 91% used [0x07420000, 0x07b560c0, 0x07c00000)
to   space 8064K,   0% used [0x06c40000, 0x06c40000, 0x07420000)
tenured generation   total 967936K, used 420542K [0x07c00000, 0x42d40000, 0x42d40000)
   the space 967936K, 43% used [0x07c00000, 0x216af9f0, 0x216afa00, 0x42d40000)
compacting perm gen total 16896K, used 16857K [0x42d40000, 0x43dc0000, 0x46d40000)
   the space 16896K, 99% used [0x42d40000, 0x43db64e8, 0x43db6600, 0x43dc0000)
No shared spaces configured.
VM Arguments:
jvm_args: -Xmx1024m -Xss4096k -Djava.util.logging.config.file=logging.properties
java_command: com.fairisaac.ruleviz.demo.Application -triad -datadisplay -edit -reorderable -comparable
Launcher Type: SUN_STANDARD
--------------- S Y S T E M ---------------
OS: Windows XP Build 2600 Service Pack 2
Memory: 4k page, physical 2097151k(1247624k free), swap 4194303k(4194303k free)
vm_info: Java HotSpot(TM) Client VM (11.0-b15) for windows-x86 JRE (1.6.0_10-b33), built on Sep 26 2008 01:00:43 by "java_re" with MS VC++ 7.1

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>
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