Altering a text file using methods, help please!

Question

Hi I'm new to this forum so please bear with me, my problem is I have written a program for a gym using methods, my program works fine but i need to add another switch (case 5:) to my program, this new switch needs to take the information from case 4: and enable me to change any details and store these changes into a new text file, I know i need a filewriter to store new details into a new text file but i cant figure out how to get the details from case 4: into case 5: and be able to alter these details on screen??, hope this is enough information as to what my problem is. Thnx
import javax.swing.JOptionPane;
import java.io.*;
     class GymProgram1
static void menu(String gym[][])
          int choice = 0;
while (choice < 1 || choice > 5)
String input = JOptionPane.showInputDialog("Enter a numerical choice to...\n1: Find customers who smoke, lost weight, use cycles, treadmills, steps, skis or weights \n2: Find customers over a certain age \n3: Find average of all customers \n4: Find a customers details \n5: Exit");
          if (input == null)
          menu(gym);
          try
          choice = Integer.parseInt(input);
          catch (NumberFormatException e)
          switch (choice)
          case 1: search(gym, choice);
                    break;
          case 2: age(gym, choice);
                    break;
          case 3: average(gym, choice);
                    break;
          case 4: details(gym, choice);
                    break;
          default: System.exit(0);
menu(gym);
static void search(String gym[][], int choice)
          String output = "";
          int column = 0;
          boolean printed = false;
switch(choice)
case 1: int yessearch = 0;
     while (yessearch < 1 || yessearch > 7)
String input = JOptionPane.showInputDialog("Enter a numerical choice to...\n1: Find customers that smoke \n2: Find customers who lost weight \n3: Find customers who use cycles \n4: Find customers who use treadmill \n5: Find customers who use steps \n6: Find customers who use ski's \n7: Find customers who use weights ");
          if (input == null)
          JOptionPane.showMessageDialog(null, "Cancel pressed");
          menu(gym);
          try
          yessearch = Integer.parseInt(input);
          catch (NumberFormatException e)
     switch (yessearch)
          case 1:     column = 3;
                    break;
          case 2: column = 4;
                    break;
          case 3:     column = 5;
                    break;
          case 4:     column = 6;
                    break;
          case 5:     column = 7;
                    break;
          case 6:     column = 8;
                    break;
          default:column = 9;
     for (int row = 0;row < gym.length ;row++ )
          if (gym[row][column].equalsIgnoreCase("yes"))
          output += gym[row][0] + " " + gym[row][1] + '\n';
          printed = true;
          if (printed == false)
          output = "No data found......";
          display(output);
static void age(String gym[][], int choice)
          String output = "";
          int column = 2;
          boolean printed = false;
          int ageentered=0;
          int customerage=0;
String input=JOptionPane.showInputDialog("Enter an age");
          if (input==null)
          JOptionPane.showMessageDialog(null, "Cancel pressed");
          menu(gym);
          try
          ageentered =Integer.parseInt(input);
          catch (NumberFormatException e)
switch(choice)
case 2:
     for (int row = 0;row < gym.length ;row++ )
          customerage=Integer.parseInt(gym[row][column]);
          if (ageentered <= customerage)
          output += gym[row][0] + " " + gym[row][1] + " = " + gym[row][2] + '\n';
          printed = true;
          if (printed == false)
          output = "No data found......";
          display(output);
menu(gym);
static void display(String output)
     JOptionPane.showMessageDialog(null, output);
static void average(String gym[][], int choice)
          boolean printed=false;
          String output="";
          int column = 0;
          int counter=0;
          int totalage=0;
          int average=0;
switch (choice)
case 3:
          column = 2;
     for (int row = 0;row < gym.length ;row++ )
          counter++;
          totalage+=Integer.parseInt(gym[row][2]);
          printed = true;
          average=totalage/counter;
          if (printed == false)
          output = "No data found......";
          output="Average age = " + average;
          display(output);
menu(gym);
static void details(String gym[][], int choice)
          String customer = "";
          String output = "";
          int column = 1;
          boolean printed = false;
switch (choice)
case 4: customer = JOptionPane.showInputDialog("Enter a customers surname");
          if (customer == null)
          JOptionPane.showMessageDialog(null, "Cancel pressed");
          menu(gym);
     for (int row = 0;row < gym.length ;row++ )
          if (gym[row][column].equalsIgnoreCase(customer))
          output += gym[row][0] + " " + gym[row][1] + "\n age = " + gym[row][2] + "\n smoke = " + gym[row][3] + "\n weight loss = " + gym[row][4] + "\n cycles = " + gym[row][5]+ "\n treadmills = " + gym[row][6] + "\n steps = " + gym[row][7] + "\n skis = " + gym[row][8] + "\n weights = " + gym[row][9] + '\n';
          printed = true;
          if (printed == false)
          output = "No data found......";
          display(output);
static String[][] inputData()
          String gym[][] = new String[25][10];
     try
          FileReader file = new FileReader ("a:/assign.txt");
          BufferedReader buff = new BufferedReader(file);
     for (int row = 0;row<gym.length ;row++ )
          for (int column = 0; column < 10;column ++)
          gym[row][column] = buff.readLine();
          buff.close();
     catch (IOException e)
     System.out.println("Error - - " + e.toString());
     return gym;
public static void main(String[] args)
          String gym[][] = inputData();
          menu(gym);
     for (int row = 0;row < gym.length ;row++ )
          System.out.println(gym[row][0] + " " + gym[row][1] + " " + gym[row][2] + " " + gym[row][3] + " " + gym[row][4] + " " + gym[row][5] + " " + gym[row][6] + " " + gym[row][7] + " " + gym[row][8] + " " + gym[row][9]);
     }

Answer 1

Thnx for the reply TJ, I'm still confused about this problem, heres what ive done now and i still cant get the details of a customer up on the screen for me to change their details, i havnt pasted the whole program this time just what ive altered in the menu and case 5:, hope you can help.
static void menu(String gym[][])
          int choice = 0;
while (choice < 1 || choice > 6)
String input = JOptionPane.showInputDialog("Enter a numerical choice to...\n1: Find customers who smoke, lost weight, use cycles, treadmills, steps, skis or weights \n2: Find customers over a certain age \n3: Find average of all customers \n4: Find a customers details \n5: Update a customers details \n6: Exit");
          if (input == null)
          menu(gym);
          try
          choice = Integer.parseInt(input);
          catch (NumberFormatException e)
          switch (choice)
          case 1: search(gym, choice);
                    break;
          case 2: age(gym, choice);
                    break;
          case 3: average(gym, choice);
                    break;
          case 4:
          case 5: details(gym, choice);
                    break;
          default: System.exit(0);
menu(gym);
static void details(String gym[][], int choice)
          String customer = "";
          String output = "";
          int column = 1;
          boolean printed = false;
switch (choice)
case 4: customer = JOptionPane.showInputDialog("Enter a customers surname");
          if (customer == null)
          JOptionPane.showMessageDialog(null, "Cancel pressed");
          menu(gym);
          for (int row = 0;row < gym.length ;row++ )
          if (gym[row][column].equalsIgnoreCase(customer))
          output += gym[row][0] + " " + gym[row][1] + "\n age = " + gym[row][2] + "\n smoke = " + gym[row][3] + "\n weight loss = " + gym[row][4] + "\n cycles = " + gym[row][5]+ "\n treadmills = " + gym[row][6] + "\n steps = " + gym[row][7] + "\n skis = " + gym[row][8] + "\n weights = " + gym[row][9] + '\n';
          printed = true;
          if (printed == false)
          output = "No data found......";
          display(output);
case 5:
     try
          String display1 = "assign.txt";
          FileInputStream fi = new FileInputStream(display1);
          byte inData[] = new byte[fi.available()];
          fi.read(inData);
          fi.close();
          String text = new String(inData);
          String textToAppend = "kjkjhjhKJ";
          byte outData[] = textToAppend.getBytes();
          FileOutputStream fo = new FileOutputStream(display1,true);
          fo.write(outData);
          fo.close();
     catch(Exception e)
     System.out.println("Error - - " + e.toString());
display(output);
menu (gym);
}