Ajout ligne dans un fichier texte en Java

	public static void FindAndUpdate ( String theInputFileName, String theOutputFileName, String theSymbol, String theCommentSymbol, String theExpression ){
		
		int myStartIndex = -1;
		String myTmpStr	 = null;
		String myOutputString	= "";
		boolean found = false;
		
		RandomAccessFile myInputFile = null;
		RandomAccessFile myOutputFile = null;
		String myLine = null;
		
		try{
			// --- Open the file
			myInputFile = new RandomAccessFile(theInputFileName, "r");
			myOutputFile = new RandomAccessFile(theOutputFileName, "rw");
			
			// --- Read line per line
			while (  (myLine = myInputFile.readLine() ) != null ){
				
				// --- Init the index for the new line
				myStartIndex = -1;
				found = false;
				myOutputString = "";
				
				myTmpStr = myLine;
				// --- And for each line, search the pattern 'theSymbol' and try to comment it
				while ( myTmpStr != "" && (myStartIndex = myTmpStr.indexOf(theSymbol)) != -1 ){
					
					found = true;
					myOutputString = myTmpStr.substring(0, myStartIndex).concat(theExpression).concat( theSymbol );
					myTmpStr = myTmpStr.substring( myStartIndex + theSymbol.length(), myTmpStr.length() );
				}
				
				// --- Add the end of the line
				if ( myTmpStr != "" )
					myOutputString += myTmpStr;
					
				// --- If the tag had been found, comment the line (add '//' at the beginning of the line
				if ( found )
					myOutputString = "\n".concat(theCommentSymbol).concat(myOutputString);
				else
					// --- No symbol found, so just write the same line
					myOutputString = "\n".concat(myLine);
				
				// --- Finally add this new line to the output file
				myOutputFile.write( myOutputString.getBytes());
			}
			
		}catch (IOException e){
			System.err.println("IOException : "+e.getMessage());
		}finally {
			// --- Close the openned files
			try{
				myInputFile.close();
				myOutputFile.close();
			}catch ( Exception e ){
				; // --- Do nothing
			}
		}
	}

public static void main ( String[] args ){
		
		String myInputFile = "C:\\CAHDD\\test\\exemple.txt";
		String myOutputFile = "C:\\CAHDD\\test\\exemple2.txt";
		String theSymbol = "export(";
		String theCommentSymbol = "//";
		String theTag = "<ICI>";
		
		FindAndUpdate(myInputFile, myOutputFile,theSymbol, theCommentSymbol, theTag);
		
		
	}