Traductor de Pascal a java Aprende programación con ejercicios Java

package PascalToCSharp;
import java.util.*;

public class Main
{
	public static void main(String[] args)
	{
		System.out.print("Enter name file: ");
		String fileName = new Scanner(System.in).nextLine();


		if ((new java.io.File(fileName)).isFile())
		{
			java.io.FileReader filePascal = new java.io.FileReader(fileName);
		    java.io.BufferedReader filePascalBufferedReader = new java.io.BufferedReader(filePascal);
			java.io.FileWriter fileCSharp = new java.io.FileWriter(fileName.substring(0, fileName.length() - 3) + "cs");
			String line;
			do
			{
				line = filePascalBufferedReader.readLine();
				if (line != null)
				{
					line = line.replace("writeLn", "Console.WriteLine");
					line = line.replace(" = ", "==");
					line = line.replace(" :=", "=");
					line = line.replace("'", "\"");
					line = line.replace("begin", "{");
					line = line.replace("end;", "}");
					line = line.replace("end.", "}");
					line = line.replace("end", "}");

					if ((line.contains("program ")) && (line.substring(line.length() - 1).equals(";")))
					{
						line = line.replace("program ", "class ");
						line = line.replace(";", "\n{\n static void Main()\n{");
					}

					if (line.contains("readLn("))
					{
						line = line.replace("readLn(", "");
						line = line.replace(");", "");
						line += " = Convert.ToInt32(Console.RadLine());";
					}

					line = line.replace("var", "");
					if (line.contains(": integer;"))
					{
						line = line.replace(": integer;", "");
						line = "int " + line.trim() + ";";
					}

					/* if ((line.Contains("for ")) &&
					    (line.Contains(" to ")) && 
					    (line.Contains(" do ")))
					 {
					     line = line.Replace("for ", "for (");
					     line = line.Replace(" to", "");
					     line = "int " + line.Trim() + ";";
					 }

					fileCSharp.write(line + System.lineSeparator());
				}
			} while (line != null);
			filePascal.close();
			fileCSharp.close();
		}
	}
}