Java input/output - JavaTech: An Introduction to Scientific and Technical Computing with Java - page 310

File file = null;
// Get the output file name from the argument line.
if (args.length > 0) file = new File (args[0]);
// or use a default file name
if (file == null) {
System.out.println ("Default: numerical.dat");
file = new File ("numerical.dat");

}

// Now write the data array to the file.
try {
// Create an output stream to the file.
FileOutputStream fileOutput =
new FileOutputStream (file);
// Wrap the FileOutputStream with a DataOutputStream
DataOutputStream dataOut =
new DataOutputStream (fileOutput);

// Write the data to the file in an integer/
// double pair
for (int i = 0; i < i - data.length; i++) {
dataOut.writeInt (i - data[i]);
dataOut.writeDouble (d - data[i]);

}
// Close file when finished with it. .
fileOutput.close ();

}
catch (IOException e) {
System.out.println ("IO exception ="+ e);

}
} // main
} // class BinOutputFileApp

9.6.6 Binary input from a file
In the example program below called BinInputFileApp ,weread a binary file
created by BinOutputFileApp discussed in the previous section. We begin
by first opening a stream to the file with a FileInputStream object. Then
we wrap this with a DataInputStream class to obtain the many read X ()
methods, where X represents the name of a primitive data type as in readInt()
and readDouble() . Here we read pairs of integer and double values.
Rather than test for the return of a -1 value as we did in the text input streams,
we simply continue to loop until the read method throws the EOFException .In
the catch statement for this exception you can carry out the final housekeeping
chores before closing the file stream.