So I'm working on a database-type program for the Java course that i'm doing and i seem to have run into a bit of a roadblock. This class compiles and runs alright but where i have a problem with it is when i try to amend the text file using the same class. All it does is overwrite whatever is on the txt file. I've tried to include a method that reads the text file first and then includes the contents in the output but i cant get it to work because the second i use Formatter.format(Scanner(system.in)) (if that makes sense) it just replaces whatever was in the file with the new input. (I hope I'm coherent.. If not, just let me know :P)
This is the code:
import java.io.File;
import java.io.FileNotFoundException;
import java.lang.SecurityException;
import java.util.Formatter;
import java.util.FormatterClosedException;
import java.util.NoSuchElementException;
import java.util.Scanner;
public class CreateTextFile
{
private Formatter output;
public void openFile()
{
try
{
output = new Formatter( "clients.txt" );
}
catch ( SecurityException securityException )
{
System.err.println(
"You do not have write access to this file." );
System.exit( 1 );
}
catch ( FileNotFoundException fileNotFoundException )
{
System.err.println( "Error opening or creating file." );
System.exit( 1 );
}
}
public void addRecords()
{
AccountRecord record = new AccountRecord();
Scanner input = new Scanner( System.in );
System.out.printf( "%s\n%s\n%s\n%s\n\n",
"To terminate input, type the end-of-file indicator ",
"when you are prompted to enter input.",
"On UNIX/Linux/Mac OS X type <ctrl> d then press Enter",
"On Windows type <ctrl> z then press Enter" );
System.out.printf( "%s\n%s",
"Enter product code, Description, width, height, depth and weight.",
"? " );
while ( input.hasNext() )
{
try
{
record.setAccount( input.next() );
record.setFirstName( input.next() );
record.setLastName( input.nextDouble() );
record.setBalance( input.nextDouble() );
record.setDepth(input.nextDouble());
record.setWeight(input.nextDouble());
if ( ((record.getAccount()).length() > 0) && ((record.getAccount()).length() <=4 ))
{
output.format( "%s %s %.2f %.2f %.2f %.2f\n", record.getAccount(),
record.getFirstName(), record.getLastName(),
record.getBalance(), record.getDepth(), record.getWeight() );
}
else
{
System.out.println(
"Product Code is between 0 and 4 characters" );
}
}
catch ( FormatterClosedException formatterClosedException )
{
System.err.println( "Error writing to file." );
return;
}
catch ( NoSuchElementException elementException )
{
System.err.println( "Invalid input. Please try again." );
input.nextLine();
}
System.out.printf( "%s\n%s",
"Enter product code, Description, width, height, depth and weight.",
"? " );
}
}
public void closeFile()
{
if ( output != null )
output.close();
}
}Is there some way to indicate to Formatter to skip like x amount of lines. Cos then i could count the lines with LineNumberReader from java.io.
Thanks for lookin,
Khodz
