Thread: Random access IO and printing to a laser printer

Hello

At 72, I may be the most clueless newbie this forum has seen! I started programming in 1980 with BASIC, actually sold some financial programs, then moved to QBasic (compiled) and programmed in it for years. Moved to Visual Basic 6 some years ago and have written many programs in this, including a major accounting suite that's in use every day.

Have looked at dot.net but I mistrust Micro$oft and wonder when they will ditch it. Hence contemplating the move to Java.

Before embarking on the relearning exercise I have two queries.

1) Can I write in Java to create and access Random Access files? I am comfortable with these. Where will I find the syntax for open, get, put, close (or whaetver the Java terms are)?

2) Can I write in Java to print financial reports (formatted) to a laser printer? Printing to a console is far too primitive for my needs. Again, where can I find the syntax?

Many thanks in advance
Alan

Originally Posted by alan1

Thank you Norm. Wow! That's a lot of info!

In Visual Basic we have a thing called User Defined Type, which in Dot Net is Structure. For example, if I have a lot of records in my random access file, each record may have name, dob, membership number, syntax rather like this:-

Stucture Bloggs
Name As String * 30 //the max length of the string
dob As Date //fixed length designated by type
membershipNo As Int //same as above
End structure

(Note: I indented the lines between the start and end lines, but the forum machine discarded the indents!)

We can address a given field in a given record by Bloggs.Name = "Smith" or Bloggs.dob = Now or Bloggs.membershipNo = Counter. Then Put #1,4 where #1 is the file number and 4 is the record no. Where can I find info about the java equivalent?

Have you looked at Java enums?
Java Enum Tutorial: 10 Examples of Enum in Java

The syntax seems similar to what you describe.

Thanks. I had trouble following that tutorial owing to the bad grammar, spelling and punctuation. I can't help feeling that there must be a closer equivalent to vb6's UDT or dot.net's Structure if only I can find it.

Would love to get an answer on laser printers too. Surely, if Java is used for financial applications then printing (hardcopy) formatted financial reports must be a well used feature?

I am very keen to get started on Java, but not if after masses of study and practice I still cannot use random access files or printers, both absolutely central to the accounting application that I would like to port from vb6!

Thanks Norm. I'll have to get my head around what classes actually are! Any luck with printing formatted data to laser printers?

Norm, is there someone at Oracle I could ask? I really need to know if this requirement can be met before embarking on learning Java. (BTW, I'll also be interested to get anyone's recommendation of a *real* beginners book that assumes nothing and *really* explains classes without just a heap of jargon!

Cheers
Alan

Originally Posted by alan1

1) Can I write in Java to create and access Random Access files? I am comfortable with these. Where will I find the syntax for open, get, put, close (or whaetver the Java terms are)?

You can use the RandomAccessFile class found in the java.io. package. Here is a link containing the syntax and its methods. You may also want to look at the File class, which is treated as a representation of a given file or directory. It is also part of the java.io. package.

Originally Posted by alan1

2) Can I write in Java to print financial reports (formatted) to a laser printer? Printing to a console is far too primitive for my needs. Again, where can I find the syntax?

I've never done this before (nor thought about it actually) so I did some Googling and it is pretty interesting. I found 2 links from Oracle that would be of some help:
Lesson: Printing (The Java™ Tutorials > 2D Graphics) (describes the steps you'll need to take)
javax.print (Java Platform SE 7 ) (details of the javax.print. package in detail)