Class Validator

[luizmeme]

I'm attempting to code a program that validates a file named as Class.txt, the contents of the file are: class test {
int i;
}

the thing is, I can't get past the first two words, class and test. Can anyone help me?

the code is as follows:

import java.io.File;
import java.io.FileReader;
import java.io.IOException;

public class Parser {

private FileReader content;
private int currentLineNumber = 1;
private int currentCharNumber = 0;
private int currentValue;
private char currentChar;
private String token;

public static void main( String[] args ) {
try {
new Parser( new File( "C:/Class.txt" ) ).parse();
} catch ( ParseException exc ) {
exc.printStackTrace();
} catch ( IOException exc ) {
exc.printStackTrace();
}
}

public Parser( File file ) throws IOException {
content = new FileReader( file );
}

public void parse() throws ParseException, IOException {

nextToken();

if ( token.equals( "class" ) ) {
System.out.println( token );
nextToken();
} else {
throw new ParseException( token, currentLineNumber, currentCharNumber );
}

identifier();

if ( token.equals( "{" ) ) {
System.out.println( token );
nextToken();
} else {
throw new ParseException( token, currentLineNumber, currentCharNumber );
}

type();
identifier();

if ( token.equals( "}" ) ) {
System.out.println( token );
nextToken();
} else {
throw new ParseException( token, currentLineNumber, currentCharNumber );
}

if ( token == null ) {
System.out.println( "file syntactically correct." );
}

}

private void type() throws ParseException, IOException {

if ( token.equals( "int" ) || token.equals( "string" ) || token.equals( "char" ) ) {
System.out.println( token );
nextToken();
} else {
throw new ParseException( token, currentLineNumber, currentCharNumber );
}

}

private void identifier() throws ParseException, IOException {

if ( token.matches( "^[a-zA-Z]+[a-zA-Z0-9]*" ) ) {
System.out.println( token );
nextToken();
} else {
throw new ParseException( token, currentLineNumber, currentCharNumber );
}

}

private void nextToken() throws IOException {

token = null;

while ( ( currentValue = content.read() ) != -1 ) {

currentChar = (char) currentValue;

if ( currentChar != ' ' && currentChar != '\n' && currentChar != ';' ) {
if ( token != null ) {
token += currentChar;
} else {
token = String.valueOf( currentChar );
}
currentCharNumber++;
} else {
if ( currentChar == ' ' ) {
currentCharNumber++;
break;
} else if ( currentChar == '\n' ) {
currentLineNumber++;
currentCharNumber = 1;
break;
}
}

}

}

}

public class ParseException extends Exception {

private String token;
private int line;
private int Char;

public ParseException( String token, int line, int Char ) {
this.token = token;
this.line = line;
this.Char = Char;
}

@Override
public String toString() {
return String.format(
"Error \"%s\" (line: %d, Char: %d)",
token, line, Char );
}

}

[keang]

Have you considered using a Doclet in conjunction with the JavaDoc program. JavaDoc parses java files and exposes the constituent parts to the plugin Doclet.

There are various on-line articles on writing Doclets such as this one