how to read csv file data and validating the data

CsvReader reader=new CsvReader("csvfile");//use csvreader.jar file
while (reader.readRecord()) {
                // This deals with embedded newlines inside quote-escaped fields
int firstRecordColumnCount = reader.getColumnCount();
                String line = reader.getRawRecord();

 string columnvalue=reader.get(position) ;//




//to read a file
 FileContents contents = new FileContents();
        FileReader in = new FileReader(args[ 3]);
        StringBuffer fileContents = new StringBuffer();
        int c;
        while ((c = in.read()) != -1) {
            fileContents.append((char) c);
        }
        contents.setFile(fileContents.toString());