gettin error with TextReader

[neha gautam]

hi all..

here is the code i m tryin to execute its givin me the error with TextReader..
i can figure why..

 
import java.io.*;
import java.util.*;

public class WordCount {

   static TextReader in;   // An input stream for reading the input file.
   static PrintWriter out; // Output stream for writing the output file.
   
   static class WordData { 
         // Represents the data we need about a word:  the word and
         // the number of times it has been encountered.
      String word;
      int count;
      WordData(String w) {
            // Constructor for creating a WordData object when
            // we encounter a new word.
         word = w;
         count = 1;  // The initial value of count is 1.
      }
   } // end class WordData
   
   static class CountCompare implements Comparator {
         // A comparator for comparing objects of type WordData
         // according to their counts.  This is used for
         // sorting the list of words by frequency.
      public int compare(Object obj1, Object obj2) {
         WordData data1 = (WordData)obj1;
         WordData data2 = (WordData)obj2;
         return data2.count - data1.count;
            // The return value is positive if data2.count > data1.count.
            // I.E., data1 comes after data2 in the ordering if there
            // were more occurrences of data2.word than of data1.word.
            // The words are sorted according to decreasing counts.
      }
   } // end class CountCompare


   public static void main(String[] args){
         // The program opens the input and output files.  It reads
         // words from the input file into a TreeMap, in which 
         // they are sorted by alphabetical order.  The words
         // are copied into a List, where they are sorted according
         // to frequency.  Then the words are copied from the
         // data structures to the output file.
   
      openFiles(args);  // Opens input and output streams, using file
                        // names given as command-line parameters.
      
      TreeMap words;  // TreeMap in which keys are words and values
                      // are objects of type WordData.
      words = new TreeMap(); 
      
      readWords(in,words);  // Reads words from the input stream and
                            // stores data about them in words.
   
      List wordsByCount;  // List will contain all the WordData
                          // values form the TreeMap, and will be
                          // sorted according to frequency count.
      wordsByCount = new ArrayList(words.values());
      Collections.sort(wordsByCount, new CountCompare());

      out.println("Words found in the file named \"" + args[0] + "\".\n");
      out.println("The number of times that the word occurred in the");
      out.println("file is given in parentheses after the word.\n\n");
      out.println("The words from the file in alphabetical order:\n");
      
      printWords(out, words.values());  // Print words alphabetically.

      out.println("\n\nThe words in order of frerquency:\n");
      
      printWords(out, wordsByCount);  // Prints words by frequency count.
      
      if (out.checkError()) {
            // Some error occurred on the output stream.
         System.out.println("An error occurred while writing the data.");
         System.out.println("Output file might be missing or incomplete.");
         System.exit(1);
      }
      
      System.out.println(words.size() + " distinct words were found.");

   } // end main()
   
   
   static void printWords(PrintWriter outStream, Collection wordData) {
         // wordData must contain objects of type WordData.  The words
         // and counts in these objects are written to the output stream.
      Iterator iter = wordData.iterator();
      while (iter.hasNext()) {
         WordData data = (WordData)iter.next();
         outStream.println("   " + data.word + " (" + data.count + ")");
      }
   } // end printWords()
   

   static void openFiles(String[] args) {
          // Open the global variable "in" as an input file with name args[0].
          // Open the global variable "out" as an output file with name args[1].
          // If args.length != 2, or if an error occurs while trying to open
          // the files, then an error message is printed and the program
          // will be terminated.
      if (args.length != 2) {
         System.out.println("Error: Please specify file names on command line.");
         System.exit(1);
      }
      try {
         in = new TextReader(new FileReader(args[0]));
      }
      catch (IOException e) {
         System.out.println("Error: Can't open input file " + args[0]);
         System.exit(1);
      }
      try {
         out = new PrintWriter(new FileWriter(args[1]));
      }
      catch (IOException e) {
         System.out.println("Error: Can't open output file " + args[1]);
         System.exit(1);
      }
   } // end openFiles()
   

   static void readWords(TextReader inStream, Map words) {
        // Read all words from inStream, and store data about them in words.
        // A word is any sequence of letters.  Words are converted to lower
        // case.  Any non-letters in the input stream are ignored.
        // When a word is encountered for the first time a key/value pair
        // is inserted into words.  The key is the word and the value is
        // a new object of type WordData containing the word.  When a word
        // is encountered again, the frequency count in the corresponding
        // WordData object is just increased by one.  If an error occurs
        // while trying to read the data, an error message is printed and
        // the program is terminated.

      try {
         while (true) { 
            while (! inStream.eof() && ! Character.isLetter(inStream.peek()))
               inStream.getAnyChar();  // Skip past non-letters.
            if (inStream.eof())
               break;  // Exit because there is no more data to read.
            String word = inStream.getAlpha();  // Read one word from stream.
            word = word.toLowerCase();
            WordData data = (WordData)words.get(word);
                // Check whether the word is already in the Map.  If not,
                // the value of data will be null.  If it is not null, then
                // it is a WordData object containing the word and the
                // number of times we have encountered it so far.
            if (data == null) {
                  // We have not encountered word before.  Add it to
                  // the map.  The initial frequency count is
                  // automatically set to 1 by the WordData constructor.
               words.put(word, new WordData(word) );
            }
            else {
                  // The word has already been encountered, and data is
                  // the WordData object that holds data about the word.
                  // Add 1 to the frequency count in the WordData object.
               data.count = data.count + 1;
            }
         }
      }
      catch (TextReader.Error e) {
         System.out.println("An error occurred while reading the data.");
         System.out.println(e.toString());
         System.exit(1);
      }

   } // end readWords()
   
   
} // end class WordCount

the error is:



C:\neha>javac WordCount.java
WordCount.java:20: cannot find symbol
symbol : class TextReader
location: class WordCount
static TextReader in; // An input stream for reading the input file.
^
WordCount.java:137: cannot find symbol
symbol : class TextReader
location: class WordCount
static void readWords(TextReader inStream, Map words) {
^
WordCount.java:121: cannot find symbol
symbol : class TextReader
location: class WordCount
in = new TextReader(new FileReader(args[0]));
^
WordCount.java:176: package TextReader does not exist
catch (TextReader.Error e) {
^
Note: WordCount.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
4 errors



i don know what i m missin.....
please help..
thanks to all

[Balu Sadhasivam]

Neha,

TextReader is not standard Java API packaged in JDK. I guess you are trying to use JSci.io.TextReader or your own TextReader class ? anyways you got import it .

Add the jsci jar and import TextReader in the java.

[neha gautam]

thanks balu......

ill try that out

[neha gautam]

even by importin its givin same error on compliation
i jus appended the progrm with:

import java.JSci.io.TextReader;


do i need to anyother thing except this
actually i hv to read my text file word by word
can you guys suggest some other way for the same.
thanks to all

[Balu Sadhasivam]

import java.JSci.io.TextReader;

Like i mentioned earlier , we don't have any idea of which TextReader Class you are using. I guessed it as "JSci.io.TextReader" and you used "java.JSci.io.TextReader" , where java comes from.

actually i hv to read my text file word by word
can you guys suggest some other way for the same.

I can think of RandomAccessFile which can read line by line. Does that suffice ?

[neha gautam]

thank you for the response balu..

textreader is not my own class but java predefined input stream..
i have read the file word by word,,,,
and not line by line...
its like the text file of the form

0.300, -124.87,
0.362, -127.36,
0.425, -129.30,
0.487, -131.52,
0.549, -133.48,
0.612, -135.43,
0.674, -137.19,
0.736, -138.74,
0.798, -140.21,
0.861, -141.52,
0.923, -142.71,
0.985, -143.86,
1.048, -144.94,
1.110, -146.01,
1.172, -146.87,
1.235, -147.60,
1.297, -148.74,
1.359, -149.45,
1.422, -150.16,
1.484, -151.03,
1.546, -151.56,
1.609, -152.31,
1.671, -152.99,
1.733, -153.76,
1.796, -154.51,
1.858, -155.06,


and my job is to read the file and display a graph between the 1st and 2nd colmns
as X and Y axis, i have my graph prgm, jus had prblm in readin the contents..
so i thought the option of reading the file word by word and storin the colmnsin separate arrays and linkin
them with graph prgrams..
kindly correct me if you think i m wrong somewhr..
thanks for all your help

[Balu Sadhasivam]

and my job is to read the file and display a graph between the 1st and 2nd colmns
as X and Y axis, i have my graph prgm, jus had prblm in readin the contents..

You could still use RandomAccessFile readLine() method() and could use StringTokenizer or spilt() method with delimiter as "space" or "comma". This way you could get word by word and store in arrays or other preferred approach you are after.

[Ulf Dittmer]

Balu Sadhasivam wrote:You could still use RandomAccessFile readLine()

RandomAccessFile really isn't the right class to use here; it's meant for circumstances that have no bearing on this case. A BufferedReader combined with a FileReader would be much more appropriate.

[Balu Sadhasivam]

A BufferedReader combined with a FileReader would be much more appropriate.

Yes, as long it has readLine() to read it easily.

[jennifer pandian]

hey neha.. I am working on a program similar to yours.. did you happen to correct your previous errors? if so, could you please post the corrected program ? It would be very useful to me.. Thanks

[Surinder Mehra]

This is probably too late to post an answer. But still for future if required, We can read this file using Scanner and split the line by comma and store the two columns into two lists. Sample is given below:

[	public static void main(String[] args) {
		try {
			Scanner sc= new Scanner(new File("input file path"));
			List<String> list1= new ArrayList<String>();
			List<String> list2= new ArrayList<String>();
			
			while (sc.hasNext()) {
				String row= sc.nextLine();
				String words[]= row.split(",");
				list1.add(words[0].trim());
				list2.add(words[1].trim());
			}
			System.out.println(list1+"\n"+list2);
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}]

[Pooja Tikhe]

hey neha will you please tell how you imported it and how you remove that TextIO, TextReader error

[Campbell Ritchie]

Welcome to the Ranch

NG hasn't posted since this thread back in 2009, so you will probably not get an answer from him. I am afraid SM's suggestion is poor quality since he neither opened nor closed the Scanner correctly, and it appears to be using parallel Lists, a design just as dubious as parallel arrays.
I suggest you use a Scanner to read the file, or a BufferedReader via the lines() method, or one of its analogues:-

try (Scanner scan =
      new Scanner(Paths.get("/home/campbell/myFile.txt")))
{
   scan.setDelimiter(",\\s*|\\s*\r?\n\\s*"); // optional
   while (scan.hasNext())
   {
      BigDecimal value1 = scan.nextBigDecimal();
      BigDecimal value2 = scan.nextBigDecimal();
      Foo f = new Foo(value1, value2);
      doSomethingWith(f);
   }
}
catch (FileNotFoundException ex)
{
   ex.printStackTrace(); // or other exception handling
}

You don't have to change the delimiter; you can use other ways to split the line if you prefer. I am not at all sure I have got that regular expression anywhere near correct.

private List<Foo> foos;
// ...
try (Stream<String> stream =
      Files.lines(Paths.get("/home/campbell/myFile.txt")))
{
   foos = stream.map(Foo::new)
                .collect(Collectors.toList());
}
catch (IOException ex)
{
   ex.printStackTrace(); // or other exception handling
}

Files#lines() method.
Stream#map() method: this takes an input Stream and uses a function to convert that to a Stream<Foo>. I am assuming (deciding!) that Foo has a constructor taking a String of the same format as that in the file. You can read about the strange‑looking syntax with :: in the Java™ Tutorials.
The name should make it obvious what sort of Collector Collectors#toList() provides.