Random Access Files concept

[AralX]

Hey 'all !
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- what is below the Update blockis answered-
~New -go to postNumber 3 , there is myQuestion-
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how is everyone ?

I want to get to under stand the concept .. of Random access files

now , that I have a file and and initialized an Object of a RandomAccessFile class .. in the form of "rw" (Read/write) ...here i can write and read randomly .. but can I Edit randomly .. like delet a file then replace it with a new data ?

thanks :)

[hardwired]

but can I Edit randomly .. like delet a file then replace it with a new data ?
Yes. The RandomAccessFile class api has methods for navigating within the raf, reading and writing. You also have String methods available. Here's an older article about RandomAccessFiles: JDC Tech Tips: May 09, 2000.

[AralX]

I don't want to Open a new thread , so I'd reather post my Question here aslong as it is related ..

when reading from a RAF .i found this exception

at java.io.RandomAccessFile.readInt(Unknown Source)
	at HardwareRecord.readRecord(HardwareRecord.java:81)
	at HardwareStoreInventory.getRecordFileandCheck(HardwareStoreInventory.java:33)
	at HardwareStoreInventory.AddFile(HardwareStoreInventory.java:12)
	at testerProg.RunOption(testerProg.java:66)
	at testerProg.RunApplication(testerProg.java:18)
	at Application.main(Application.java:19)

the line 81 is

	setRecordnumber(datafile.readInt());
		setToolName(StringModifierReader(datafile));
		setQuantity(datafile.readInt());
		setCost(datafile.readDouble());

and from a website it says that this Kind of exception when Occures with readInt() of the RAF
is usuallu because that it reached the eand of the file before 4 Bytes .. or something like that

but I have calculated the File length correctly
4 Bytes(Int)* 2(I have two)= 8
8Bytes(Double)*1 = 8 +
30Bytes(String of 15Chars)=30+
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the Total is 46
which will be the size of each file right ?

what do you people suggest me to do in order to handle the Exception ?

Thanks again :)

has been solved just now incase you are woundering... the file was Empty, thats why :D

thanks everyone