Question

I have a simple text dictionary file, which contains words, separated by ‘;’.My problem is to read all words and store them in map without loading all file to a string(dictionary file may be very huge).
Here is my code, where i am trying to print these words to a console :

 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.FileReader;
 import java.io.IOException;
 import java.util.Map;

 public class Dictionary {
private static Dictionary instance;
private Map DictionaryMap;
private String delimiter;

private Dictionary() {

}

private Dictionary(String dictfile, String delimiter) throws FileNotFoundException, IOException
{
    FileReader fr = new FileReader(dictfile);
    int position = 0;
    StringBuffer buffer = new StringBuffer();
    while ((position = fr.read()) != -1) {
        char symbol = (char) fr.read();
        if(symbol != ';') {
            buffer.append(symbol);
            System.out.println("Char is : "+symbol+" ;");
        } else {
            System.out.println("String is "+buffer+" ;");
            buffer.delete(0, buffer.length()-1);
        }
    }
}

public void loadFromFile(File dictfile, String delimiter) {

}

public String getDelimiter() {
    return delimiter;
}

public void setDelimiter(String delimiter) {
    this.delimiter = delimiter;
}

But when i am trying to run this code on sample dict.txt file, which contains :

test1;test2 ;

Some of the symbols between delimiter (char ‘;’) doesn’t displays :

Char is : e ;
Char is : t ;
String is et ;
Char is : e ;
Char is : t ;
Char is : ;
Char is : \uffff ;

My question why it doesn’t works properly and how to read chars from fileinputstream (in my case) without type casting?

Answer 1

You are calling fr.read() twice e.g.

while ((position = fr.read()) != -1) {
    char symbol = (char) fr.read();

Therefore you are skipping input.

This should be:

  while ((position = fr.read()) != -1) {
    char symbol = (char) position;

Also it’s not generally a good idea to read the file 1 character at a time – you should try and use a char [] as a buffer and use the read(char[] cbuf, int off, int len) method, or for simplicity, use a BufferedReader.