problem to get the zos file size #5

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1. fjeremic commented on Mar 9, 2021

   

   fjeremic

   on Mar 9, 2021

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   To get a dataset size you can use the getLrecl API from the com.ibm.jzos package. You can find full documentation here:
   https://www.ibm.com/support/knowledgecenter/SSYKE2_7.0.0/com.ibm.java.zsecurity.api.70.doc/com.ibm.jzos/com/ibm/jzos/ZFile.html#getLrecl()

   There is an example of using the API to read entire contents of a dataset into a byte[] here:
   https://www.ibm.com/support/knowledgecenter/en/SSYKE2_7.1.0/com.ibm.java.zsecurity.api.71.doc/com.ibm.jzos/com/ibm/jzos/RecordReader.html
2. matmass commented on Mar 10, 2021

   

   matmass

   on Mar 10, 2021

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   Thanks for the reply.

   So if I understand, we need to read the file and to count the bytes.

   It means that we can't get directly the file size as a property.

   Is-there any other way to get it?

   Regards,
   Mathias.
3. fjeremic commented on Mar 10, 2021

   

   fjeremic

   on Mar 10, 2021

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   You do not need to read the whole dataset to get it's length. The example in the second link above does that, but if all you want is the length of the dataset you can just use getLrecl. What the second example does is it creates a RecordReader and uses getLrecl to get the size of the dataset, then it allocates a byte[] using the size and reads the entire dataset into the byte[].

   This is not what you need. You can just directly create a ZFile and use the API in my first link.

   Here is how the constructor of ZFile looks (with examples):
   https://www.ibm.com/support/knowledgecenter/SSYKE2_7.0.0/com.ibm.java.zsecurity.api.70.doc/com.ibm.jzos/com/ibm/jzos/ZFile.html#ZFile(java.lang.String,%20java.lang.String)

   So if your dataset is SYS1.HELP(ACCOUNT) as in the example, you can do:

   ZFile dsn = new ZFile("//'SYS1.HELP(ACCOUNT)'", "rt");
   int datasetSizeInBytes = dsn.getLrecl();