reading a random access file
- by user1067332
The file I create has text in it, but when i try to read it, the output is null.
here is the file the creates the text file, it creates the file and puts it in the right postion
import java.util.*;
import java.io.*;
public class CreateCustomerFile
{
public static void main(String[] args) throws IOException
{
int pos;
RandomAccessFile it =
new RandomAccessFile("CustomerFile.txt", "rw");
Scanner input = new Scanner(System.in);
int id;
String name;
int zip;
final int RECORDSIZE = 100;
final int NUMRECORDS = 1000;
final int STOP = 99;
try
{
for(int x = 0; x < NUMRECORDS; ++x)
{
it.writeInt(0);
it.writeUTF("");
it.writeInt(0);
}
}
catch(IOException e)
{
System.out.println("Error: " + e.getMessage());
}
finally
{
it.close();
}
it =
new RandomAccessFile("CustomerFile.txt","rw");
try
{
System.out.print("Enter ID number" +
" or " + STOP + " to quit ");
id = input.nextInt();
while(id != STOP)
{
input.nextLine();
System.out.print("Enter last name");
name = input.nextLine();
System.out.print("Enter zipcode ");
zip = input.nextInt();
pos = id - 1;
it.seek(pos * RECORDSIZE);
it.writeInt(id);
it.writeUTF(name);
it.writeInt(zip);
System.out.print("Enter ID number" +
" or " + STOP + " to quit ");
id = input.nextInt();
}
}
catch(IOException e)
{
System.out.println("Error: " + e.getMessage());
}
finally
{
it.close();
}
}
}
Here is the file to read, the pos is correct but ouput always goes to the error: null.
import javax.swing.*;
import java.io.*;
public class CustomerItemOrder
{
public static void main(String[] args) throws IOException
{
int pos;
RandomAccessFile it =
new RandomAccessFile("CustomerFile.txt","rw");
String inputString;
int id, zip;
String name;
final int RECORDSIZE = 100;
final int STOP = 99;
inputString = JOptionPane.showInputDialog(null,
"Enter id or "+ STOP + " to quit");
id = Integer.parseInt(inputString);
try
{
while(id != STOP)
{
pos = id -1 ;
it.seek(pos * RECORDSIZE );
id = it.readInt();
name = it.readLine();
zip = it.readInt();
JOptionPane.showMessageDialog(null, "ID:" + id +
" last name is " + name + " and zipcode is " + zip);
inputString = JOptionPane.showInputDialog(null,
"Enter id or " + STOP + " to quit");
id = Integer.parseInt(inputString);
}
}
catch(IOException e)
{
System.out.println("Error: " + e.getMessage());
}
finally
{
it.close();
}
}
}
