Little help with reading files

[bert ngo]

Hi I just started my java data structure class this semester and part of my homework is to make a department report. The part where i'm having hard time thinking about is how to read a binary file hoping anyone could give a steer in the right direction to how to read binary files and then inputting that data into a department report. I know how to read the file that makes up the departments which i have shown below. I was thinking if the employee is a binary file would i have to use a DataInputStream?
thanks for the help

A,Administration,302
E,Engineering,186
C,Construction,240
S,Sales,239
M,Marketing,250

[Ernest Friedman-Hill]

What do you mean exactly by "binary file?" What you've shown looks like text. If they've actually given you a binary file to read, they would have to specify the format exactly; have they done that?

[bert ngo]

im sry let me clarify wat i mean. first i cannot attach the file i need to read because it is a .dat file. So my professor has given me a file called Employee.dat and i need to read it. I need to be able to read the file so the following is defined:

EmployeeID - 3 bytes ASCII
Employee/Contractor Indicator - 1 byte ASCII 'E' for employee, 'C' for contractor
Department Code - 1 byte ASCII
First Name - 20 bytes ASCII blank padded
Last Name - 15 bytes ASCII blank padded
Salary - float single precision
Hire Date - 1 byte binary identifies the month, 1 byte binary identifies the day, 2 bytes binary identifies the year
Vacation Days - 2 bytes signed binary
Training - 1 byte

hope i cleared this up. O and the text i showed in my first post is the departments i need to have Employee.dat inputted into it. The numbers after each department will be its corresponding department code
A,Administration,302
E,Engineering,186
C,Construction,240
S,Sales,239
M,Marketing,250

[Lucas Franceschi]

well, actually you would need to have a FileReader and Buffered Reader (take a look here for this classes.)

        String yourFile = C:/File.dat //the path for your file

        //here you create a file reader object, 
        FileReader fileReader = new FileReader(yourFile);
        
        //Now you create a buffered reader for your file reader
        BufferedReader bufferedReader = new BufferedReader(fileReader);

As I said, try lookin on documentation or even in javaranch for this classes, you may find something that helps you more.

Then, to read the file in a linear way [1st line -> 2nd line -> 3rd line .....], you'll need to have a loop, that will loop until the buffered reader can't find a "next line"

        while((String line = bufferedReader.readLine()) != null) 
        {
            //at this time, the String "line" will hold the value of the line your buffered reader is actually reading.
            //perform an action that would be repeated on every line of your file.
        }

hope i've helped


Regards!

[Lucas Franceschi]

but i'm also sure that if your professor asked you to solve this, is because solving it is part of your education. asking in forums will get a respone and will for sure make you learn how to do it, but you lose the greater learning that you have when you need to solve something on your own, and I think that this greater learning is that your professor wants you to have.

anyway, good luck.

[Ernest Friedman-Hill]

Lucas Franceschi wrote:well, actually you would need to have a FileReader and Buffered Reader

Please note that this is appropriate only for a text file, and not for a binary file! The "Reader" classes are only appropriate for pure text files.

Your original suggestion of DataInputStream was absolutely correct; you'll want to use a FileInputStream and a DataInputStream together:

DataInputStream dis = new DataInputStream(new FileInputStream("yourfile.dat"));

[Lucas Franceschi]

Ernest Friedman-Hill wrote:
Please note that this is appropriate only for a text file, and not for a binary file! The "Reader" classes are only appropriate for pure text files.

sorry, didn't noted that.

[bert ngo]

DataInputStream dis = new DataInputStream(new FileInputStream("yourfile.dat"))

Thanks a lot i had a hard time thinking about how to reads this file cuz i didnt do alot with files in my previous course. I think i can handle the rest
thanks again!

[Campbell Ritchie]

"Because" please, not "cuz." Please have a look at this FAQ

[bert ngo]

I apologize I will remember for next time to use real words.

[Campbell Ritchie]

Apologies accepted