I am trying to build a compiler using Java Code. I am stuck at the Lexical Analyzer Stage and am not getting the output I want.
The Code:

1)Lexical Analyzer

public class LexicalAnalyzer {

	int lexemebegin;
	int state;
	Symbol tokenValue;
	TokenType currentTokenType;
	String Shura;
	int lineNumber;
	int position=-1;
	String lexeme;
	SymbolTable Symb;

	Scanner scan;
	
	public LexicalAnalyzer(SymbolTable hash)
	{
		Symb=hash;
	}
	
	public TokenType nextToken()
	{
		char c;
		state = 0;
		c = nextChar();
		
		while (true)//there is a token
		{
			switch (state)
			{
				case 0:	if (c=='<')
							state=1;
						else
							if(c=='=')
							{
								tokenValue = Symb.get("=");  
								return currentTokenType = TokenType.EQ;
							}
							else 
								if(c=='>')
									state=6;
								else 
									fail();
						break;
				case 1:	
				{	
						c = nextChar ( );
						if (c=='=')
						{
							tokenValue = Symb.get("<=");
							return currentTokenType = TokenType.GE;
						}
						else
							if (c=='>')
							{
								tokenValue = Symb.get("<>");
								return currentTokenType = TokenType.NE;
							}
								else
								{
									retract();
									tokenValue= Symb.get("<");  
									return currentTokenType = TokenType.LT;
								}
				}	
						
				case 6:	
				{
					c = nextChar ( );	
					if (c=='=')
						{
							tokenValue= Symb.get(">=");
							return currentTokenType = TokenType.GE;
						}
						else
						{
							retract();
							tokenValue = Symb.get(">");  
							return currentTokenType = TokenType.GT;
						}
				}
				case 9:	if ((c>='A' && c<='Z')||(c>='a' && c<='z'))
						{
							lexeme = "" +c;
							state = 10;
						}
						else 
							fail();
				break;
				case 10: 
				{
					c = nextChar();
					while ((c>='A' && c<='Z')||(c>='a' && c<='z')||(c>='0' && c<='9'))
					{
						lexeme = lexeme + c;
						c = nextChar();
					}
					//retract();
					if (Symb.containsKey(lexeme))
						tokenValue = Symb.get(lexeme);
					else 
					{
						tokenValue=new Symbol(TokenType.ID,lineNumber,position,lexeme);
						Symb.put(lexeme, tokenValue);
					}
					return currentTokenType= TokenType.ID;
				}
				case 12: 
					if (c==':')
						state=13;
					else
						if (c==';')
						{
							tokenValue = Symb.get(";");  
							return currentTokenType = TokenType.SCOLON;
						}
						else
							if  (c=='.')
							{
								tokenValue = Symb.get(".");  
								return currentTokenType = TokenType.PERIOD;
							}
							else
								if (c==',')
								{
									tokenValue = Symb.get(",");  
									return currentTokenType = TokenType.COMMA;
								}
								else
									if (c=='(')
									{
										tokenValue = Symb.get("(");
										return currentTokenType = TokenType.OP;
									}
									else
										if (c==')')
										{
											tokenValue = Symb.get(")");
											return currentTokenType = TokenType.CP;
										}
										else
											fail();
					break;
				case 13:
				{
					c = nextChar();
					if (c=='=')
					{
						tokenValue = Symb.get(":"+c);
						return currentTokenType = TokenType.ASSIGN;
					}
					else
					{
						retract();
						tokenValue= Symb.get(":");  
						return currentTokenType = TokenType.COLON;
					}
				}
				case 21:
					if (c=='+')
					{
						tokenValue = Symb.get("+");
						return currentTokenType = TokenType.PLUS;
					}
					else
						if (c=='-')
						{
							tokenValue = Symb.get("-");  
							return currentTokenType = TokenType.MINUS;
						}
						else
							if (c=='*')
							{
								tokenValue = Symb.get("*");  
								return currentTokenType = TokenType.MULT;
							}
							else
								if (c=='/')
								{
									tokenValue = Symb.get("/");  
									return currentTokenType = TokenType.DIV;
								}
								else
									fail();
					break;
				case 26:
					if (c>='0' && c<='9')
					{
						lexeme = "" + c;
						state = 27;
					}
					else 
						fail();
					break;
				case 27:
				{
					c = nextChar();
					while (c>='0' && c<='9')
					{
						lexeme = lexeme + c;
						c = nextChar();
					}
					retract();
					if (Symb.containsKey(lexeme))
						tokenValue = Symb.get(lexeme);
					else 
					{
						tokenValue=new Symbol(TokenType.NUM,lineNumber,position,lexeme);
						Symb.put(lexeme, tokenValue);
						
					}
					return currentTokenType = TokenType.NUM;
				}
					
				case 29:
					if(c==' ')
						state = 30;
					else     
						return currentTokenType = TokenType.DELIM;
					break;
				case 30:
				{
					c = nextChar();
					while (c==' ')
						c = nextChar();
					state = 0;
					break;
				}	
			}
		}
	}			
	//îçæéø àú òøê äèå÷ï
	public Symbol GetTokenValue()
	{
		return this.tokenValue;
	}
	
	
	//÷åøà ùåøåú åî÷ãí àåúï
	public char nextChar()  
	{
		position++;
			if (position >= Shura.length())//end on line
				if(scan.hasNext())
				{
					Shura=scan.nextLine();
					lineNumber++;
					position=0;
					return Shura.charAt(position);
				}
				else // end of file
				{
					currentTokenType = TokenType.FINISH;
					return (' ');
				}
			else //middle of line
				return Shura.charAt(position);
			}
	//î÷èéï àú äîé÷åí á1
	public void retract()
	{
		position--;
	}
	//îùðä àú äòøê ùì äñèééè
	public void fail()
	{
		switch (state)
		{
		case 0: state=9; break;
		case 9: state=12; break;
		case 12: state=21; break;
		case 21: state=26; break;
		case 26: state=29; break;
		}
	}
	//îãôéñ àú äèå÷ï
	public void PrintToken()
	{
		System.out.println(tokenValue.value.toString());
	}
	
	public void inputFileName(String fname)
	{
		try
		{
			scan=new Scanner(new File(fname));
			Shura=scan.nextLine(); 
		}
		catch (Exception e)
		{
			System.out.println (e.getMessage());
		}		
	}
}

2)Symbol Table:

enum TokenType {NUMBER, RESERVEDWORD, ID, LT, GT, EQ, LE, GE, NE, OP, CP, ASSIGN, PLUS, MINUS, MULT, DIV, DELIM, COMMA, COLON, PERIOD, SCOLON, NUM, FINISH}

public class SymbolTable 
{
	Hashtable <String, Symbol> hash;
		
	
	public Symbol get (String str) 
	{
		 return hash.get(str);
	}
	public boolean containsKey(String lexeme)
	{
		return hash.containsKey(lexeme); 
	}	
	public void put (String lexeme,Symbol sym)
	{
		hash.put(lexeme, sym);
	}

	public SymbolTable ( )
	{
	hash = new Hashtable <String,Symbol> ();
	//àéúçåì èáìú äòøáåì
	
	Symbol semel = new Symbol(TokenType.RESERVEDWORD, 0, 0, "program");
	hash.put("program", semel);
	semel = new Symbol(TokenType.RESERVEDWORD, 0, 0, "var");
	hash.put("var", semel);
	semel = new Symbol(TokenType.RESERVEDWORD, 0, 0, "begin");
	hash.put("begin", semel);
	semel = new Symbol(TokenType.RESERVEDWORD, 0, 0, "end");
	hash.put("end", semel);
	semel = new Symbol(TokenType.RESERVEDWORD, 0, 0, "if");
	hash.put("if", semel);
	semel = new Symbol(TokenType.RESERVEDWORD, 0, 0, "then");
	hash.put("then", semel);
	semel = new Symbol(TokenType.RESERVEDWORD, 0, 0, "else");
	hash.put("else", semel);
	semel = new Symbol(TokenType.RESERVEDWORD, 0, 0, "while");
	hash.put("while", semel);
	semel = new Symbol(TokenType.RESERVEDWORD, 0, 0, "do");
	hash.put("do", semel);
	semel = new Symbol(TokenType.RESERVEDWORD, 0, 0, "integer");
	hash.put("integer", semel);
	semel = new Symbol(TokenType.RESERVEDWORD, 0, 0, "read");
	hash.put("read", semel);
	semel = new Symbol(TokenType.RESERVEDWORD, 0, 0, "write");
	hash.put("write", semel);
	semel = new Symbol(TokenType.RESERVEDWORD, 0, 0, "or");
	hash.put("or", semel);
	semel = new Symbol(TokenType.RESERVEDWORD, 0, 0, "and");
	hash.put("and", semel);
	semel = new Symbol(TokenType.RESERVEDWORD, 0, 0, "not");
	hash.put("not", semel);
	
	semel = new Symbol(TokenType.ASSIGN, 0, 0, ":=");
	hash.put(":=", semel);
	semel = new Symbol(TokenType.SCOLON, 0, 0, ";");
	hash.put(";", semel);
	semel = new Symbol(TokenType.PERIOD, 0, 0, ".");
	hash.put(".", semel);
	semel = new Symbol(TokenType.COMMA, 0, 0, ",");
	hash.put(",", semel);
	semel = new Symbol(TokenType.OP, 0, 0, "(");
	hash.put("(", semel);
	semel = new Symbol(TokenType.CP, 0, 0, ")");
	hash.put(")", semel);
	semel = new Symbol(TokenType.COLON, 0, 0, ":");
	hash.put(":", semel);
	
	semel = new Symbol(TokenType.LT, 0, 0, "<");
	hash.put("<", semel);
	semel = new Symbol(TokenType.GT, 0, 0, ">");
	hash.put(">", semel);
	semel = new Symbol(TokenType.LE, 0, 0, "<=");
	hash.put("<=", semel);
	semel = new Symbol(TokenType.GE, 0, 0, ">=");
	hash.put(">=", semel);
	semel = new Symbol(TokenType.EQ, 0, 0, "=");
	hash.put("=", semel);
	semel = new Symbol(TokenType.NE, 0, 0, "<>");
	hash.put("<>", semel);
	
	semel = new Symbol(TokenType.PLUS, 0, 0, "+");
	hash.put("+", semel);
	semel = new Symbol(TokenType.MINUS, 0, 0, "-");
	hash.put("-", semel);
	semel = new Symbol(TokenType.MULT, 0, 0, "*");
	hash.put("*", semel);
	semel = new Symbol(TokenType.DIV, 0, 0, "/");
	hash.put("/", semel);
	}
}

3) Class Symbol:

class Symbol 
{
	TokenType sym;	//token type
	int lineNumber;
	int position;
	Object  value;	//semantic value of token


	Symbol (TokenType symb, int ln, int pos, Object val)
	{
		sym = symb;
		lineNumber = ln;
		position = pos;
		value = val;
	}
}

4)Main Class:

public class Run 
{
	public static void main(String[] args) 
	{
		try
		{
			Scanner input = new Scanner (System.in);
			String fname;
		
			SymbolTable St = new SymbolTable();
			LexicalAnalyzer la = new LexicalAnalyzer(St);
		
			System.out.println("Type in the file name you wish to Compile");
			fname = input.nextLine();
			la.inputFileName(fname);
			
			TokenType currentToken=la.nextToken();
			while(currentToken != TokenType.FINISH)
			{
				la.PrintToken();
				System.out.println();
				currentToken=la.nextToken();
			}
		}
		catch (Exception e)
		{
			System.out.println(e.getMessage());
		}
	}
}

The results of the code when run on a text file has a few words repeating themselves. And it doesn't stop running.
If anyone can give me a little direction on where to continue from here I would greatly appreciate it.

Thank You!!

Too much code... Anyway, what is the grammar of the language? And could you give a short sample of the language to be passing in?

LexicalAnalyzer:
method public TokenType nextToken()
line 26 while (true)//there is a token

method public char nextChar()
line 250-254 else // end of file
1. first solution:
change constant "true" to the variable, and set to false when "end of file" was detected,
2. second:
change the state variable to for example 99
detect this value as case 99: and return currentTokenType = TokenType.FINISH;

I wasn't sure which code to include and what not to so I attached it all.
The accepted language is a form of pascal.
begin
program if mone > 54 then
count = 49
end .
would be accepted.

I want to try your second solution but cannot return currentTokenType=tokentype.FINISH because I am returning char's and the program wont allow me to return anything of that type. I am not exactly sure what you meant by example 99. Can you try to explain it to me again?

3-rd. solution
your method nextChar() at end of file returns space and also sets currentTokenType to TokenType.FINISH. Check it in case 30:

case 30: {
                    c = nextChar();
                    while (c == ' ') {
                        //
                        if (currentTokenType == TokenType.FINISH) {
                            return currentTokenType;
                        }
                        //
                        c = nextChar();
                    }
                    state = 0;
                    break;
                }

I have tried you 3rd idea and thank god it has worked and my program now stops but a new prob creeps up, the first letter of words or numbers disappear. Not sure which problem is easier to deal with.
I appreciate the help you have been giving me, its been very useful.

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