I think ArrayList is calling annoyCoder (Coder c) method

[HyperFlexed]

Okay, here's the scoop. I have to code a program that parses .logo files for a LOGO emulator in java. I am having trouble with my ArrayList. I have one set up to hold all the tokens collected when a line from the file is read in (as one line can hold multiple commands). This ArrayList is called 'tokens'.

I tried calling the 'ensureCapacity' method passing in the 'countTokens' value returned by the StringTokenizer object in my method here but I keep getting "out of bounds errors". How am I supposed to resize my arraylist?

I will post the method here. Any help is greatly appreciated.

edit : 'willParseInt' is just a method I wrote that returns true or false depending on if a String can be converted to an int using Integer.parseInt

code:

/**      * Runs a .logo file in 6 steps.      * First, the number of command lines in a given file are counted. The method      * then loads all of the commands into an array of 'LogoCmd' objects. During      * this, the number of errors and comments found are counted. If errors are      * found, the user will have the option of running the error checker or      * ignoring all bad entries. The turtle is then run with the commands.      *      * @param magnitudeTokens a string with all the tokens that require a magnitude      * @param simpleTokens a string with all the tokens not needing a magnitude      * @throws IOException if there is an error reading a file      */     public static void runLogo (String magnitudeTokens, String simpleTokens) throws IOException     {         BufferedReader f;         String filePath;         String inputBuffer = "";         int commentCounter, errorCounter;         StringTokenizer tokenizer;         //Expandible Arrays         ArrayList commands = new ArrayList (0);   //For the LogoCmd objects         ArrayList tokens = new ArrayList ();      //To gather all the tokens in a line         //Clear the screen         c.clear ();         //Display the title         c.println ("== Preparing to run a .logo file =========================\n");         //Get the filepath of the .logo         while (true)         {             c.print ("Enter the name of your file : ");             try             {                 filePath = c.readLine ();                 f = new BufferedReader (new FileReader (filePath));                 break;             }             catch (IOException e)             {                 c.println ("  --> Error opening file. Ensure that this file exists.");             }         }         //Count and display the number of lines in this file         c.println ("");         c.println ("This file contains " + countLines (filePath) + " lines.");         //Start adding the commands to the expandable array         c.println ("");         c.println ("J-LOGO is now parsing this file...");         //Read current line and pass all tokens into the 'tokens' arrayList         do         {             //Pull a line from the file             inputBuffer = f.readLine ();             if (inputBuffer == null)                 break;             //Resize token array and load tokens for the line             tokenizer = new StringTokenizer (inputBuffer, " ");             tokens.ensureCapacity(tokenizer.countTokens () + 10);             for (int tok = 1 ; tok <= tokenizer.countTokens () ; tok++)             {                 tokens.add (tok - 1, tokenizer.nextToken ());             }             //Parse commands and load them into the 'commands'             int tokenAt = 1;             while (true)             {                                 //Break the loop if the token is a comment or if tokenAt exceeds the 'tokens' Array size                 if (((String) tokens.get (tokenAt - 1)).indexOf ("!!") > -1 || tokenAt > tokens.size ())                 {                     break;                 }                                 //Check to see if the command is one that requires a magnitude                 if (magnitudeTokens.indexOf ((String) tokens.get (tokenAt - 1)) > -1)                 {                     //If the next token is a number, make a LogoCmd object with the given magnitude                     if (willParseInt (((String) tokens.get (tokenAt))))                     {                         commands.add (new LogoCmd ((String) tokens.get (tokenAt - 1), Integer.parseInt ((String) tokens.get (tokenAt))));                         tokenAt += 2;                     }                     //If the next token is not a number, make a LogoCmd object with magnitude 1                     else                     {                         commands.add (new LogoCmd ((String) tokens.get (tokenAt - 1), 1));                         tokenAt++;                     }                 }                 //If the command doesn't require a magnitude, create a new no magnitude LogoCmd object                 else if (simpleTokens.indexOf ((String) tokens.get (tokenAt - 1)) > -1)                 {                     commands.add (new LogoCmd ((String) tokens.get (tokenAt - 1)));                     tokenAt++;                 }             }         }         while (inputBuffer != null);     } //runLogo (String, String)

[HyperFlexed]

A friend reccomended I use vectors.

here's the whole class just for kicks. Now I'm getting a NullPointerException when I run and try to pass in a logo file.

code:

// The "Logo" class. import java.awt.*; import hsa.Console; import java.io.*; import java.util.*; public class Logo {     static Console c;           // The output console     /**      * Checks to see if a string can be parsed to an int      *      * @param testString string to be tested      * @return returns true or false      */     public static boolean willParseInt (String testString)     {         //Try parsing to an int         try         {             Integer.parseInt (testString);         }         //Catch an exception if it occurs         catch (NumberFormatException e)         {             //An exception was found, return false             return false;         }         //If no exception occurs, this method returns true         return true;     } //willParseInt (String)     /**      * Runs a .logo file in 6 steps.      * First, the number of command lines in a given file are counted. The method      * then loads all of the commands into an array of 'LogoCmd' objects. During      * this, the number of errors and comments found are counted. If errors are      * found, the user will have the option of running the error checker or      * ignoring all bad entries. The turtle is then run with the commands.      *      * @param magnitudeTokens a string with all the tokens that require a magnitude      * @param simpleTokens a string with all the tokens not needing a magnitude      * @throws IOException if there is an error reading a file      */     public static void runLogo (String magnitudeTokens, String simpleTokens) throws IOException     {         BufferedReader f;         String filePath;         String inputBuffer = "";         int commentCounter, errorCounter;         StringTokenizer tokenizer;         //Expandible Arrays         Vector commands = new Vector (1, 1);  //For the LogoCmd objects         Vector tokens = new Vector (1, 1);    //To gather all the tokens in a line         //Clear the screen         c.clear ();         //Display the title         c.println ("== Preparing to run a .logo file =========================\n");         //Get the filepath of the .logo         while (true)         {             c.print ("Enter the name of your file : ");             try             {                 filePath = c.readLine ();                 f = new BufferedReader (new FileReader (filePath));                 break;             }             catch (IOException e)             {                 c.println ("  --> Error opening file. Ensure that this file exists.");             }         }         //Count and display the number of lines in this file         c.println ("");         c.println ("This file contains " + countLines (filePath) + " lines.");         //Start adding the commands to the expandable array         c.println ("");         c.println ("J-LOGO is now parsing this file...");         //Read current line and pass all tokens into the 'tokens' arrayList         do         {             //Pull a line from the file             inputBuffer = f.readLine ();             if (inputBuffer == null)                 break;             //Resize token array and load tokens for the line             tokenizer = new StringTokenizer (inputBuffer, " ");             tokens.setSize (tokenizer.countTokens ());             for (int tok = 1 ; tok <= tokenizer.countTokens () ; tok++)             {                 tokens.add (tok - 1, (String) tokenizer.nextToken ());             }             //Parse commands and load them into the 'commands'             int tokenAt = 1;             while (true)             {                 //Break the loop if the token is a comment or if tokenAt exceeds the 'tokens' Array size                 if (((String) tokens.elementAt (tokenAt - 1)).indexOf ("!!") > -1 || tokenAt > tokens.size ())                 {                     break;                 }                 //Check to see if the command is one that requires a magnitude                 if (magnitudeTokens.indexOf ((String) tokens.elementAt (tokenAt - 1)) > -1)                 {                     //If the next token is a number, make a LogoCmd object with the given magnitude                     if (willParseInt (((String) tokens.elementAt (tokenAt))))                     {                         commands.addElement (new LogoCmd ((String) tokens.elementAt (tokenAt - 1), Integer.parseInt ((String) tokens.elementAt (tokenAt))));                         tokenAt += 2;                     }                     //If the next token is not a number, make a LogoCmd object with magnitude 1                     else                     {                         commands.addElement (new LogoCmd ((String) tokens.elementAt (tokenAt - 1), 1));                         tokenAt++;                     }                 }                 //If the command doesn't require a magnitude, create a new no magnitude LogoCmd object                 else if (simpleTokens.indexOf ((String) tokens.get (tokenAt - 1)) > -1)                 {                     commands.addElement (new LogoCmd ((String) tokens.elementAt (tokenAt - 1)));                     tokenAt++;                 }             }         }         while (inputBuffer != null);     } //runLogo (String, String)     /**      * Returns the number of lines in the text file at the provided      * path.      *      * @param filePath path to the file to be counted      * @return The number of lines counted before 'null' was returned      * @throws IOException If there is an error reading the file      */     public static int countLines (String filePath) throws IOException     {         BufferedReader f = new BufferedReader (new FileReader (filePath));         int lineCounter = 0;         String inputBuffer = "";         //Count lines and add to counter until 'null' is returned.         while (inputBuffer != null)         {             inputBuffer = f.readLine ();  //read a line from file             if (inputBuffer != null)      //check if null is ! returned             {                 lineCounter++;              //add to counter             }             else                          //null is returned             {                 break;                      //exit the loop immeadiately             }         }         return lineCounter;               //return 'lineCounter'     } //countLines (String)     /**      * Reports all the errors in a file in a new console window.      * NOTE : CURRENTLY INCOMPLETE      *      * @param filePath path to the file to be error checked      * @param commands an array of LogoCmd objects with the data to check      */     public static void errorReport (String filePath, LogoCmd commands[])     {         Console e = new Console (20, 80, "Error Report");     } //errorReport (String, LogoCmd)     public static void main (String[] args) throws IOException     {         c = new Console ();         final String cmdsMagnitude = "fd bk lt rt lw lc";         final String cmdsNoMagnitude = "hm pu pd";         char menuInput;         //Main program loop         while (true)         {             //Clear the screen             c.clear ();             //Display the menu             c.println (" *******************************  ");             c.println (" |  J - LOGO                   |  ");             c.println (" *********************************");             c.println ("   | 1) Run a .logo              |");             c.println ("   | 2) Exit Program             |");             c.println ("   *******************************");             //Prompt user for input             menuInput = c.getChar ();             //Perform the appropriate operation             switch (menuInput)             {                 case '1':                     runLogo (cmdsMagnitude, cmdsNoMagnitude);                     break;                 case '2':                     System.exit (0);                 default:             }         }         //Close the console         //c.close ();     } //main (String []) } // NewLogo class

and here is the data for a test logo file

code:

fd 100 bk 30 !!This is a comment, it schould be ignored lt 43 rt 43 !!after this should be ignored bk20 hm fd fd fd fd fd fd fd