CSV File Parser

Reads a comma separated value file(CSV) using java

package config.java.custom.tasks;


import java.io.*;

import java.util.ArrayList;

import java.util.HashMap;

import java.util.StringTokenizer;

import ariba.util.core.StringUtil;

import com.sun.org.apache.xml.internal.utils.FastStringBuffer;



public class CSVParser
{
    FastStringBuffer fsbRecordsWithFileOrAQLError = null;// buffer file read errors
//    FastStringBuffer fsbRecordsWithIncorrectAmount = null;// buffer for amount mismatch
    FastStringBuffer fsbRecordsWithIncorrectFieldCount = null;// buffer for incorrect number of fields in row
    FastStringBuffer fsbRecordsWithNullValues = null;// buffer for null fields in row

 
    
    private static String sCSVFile = null;
   private static ArrayList alUniqueKey = null;
   private static HashMap alCSVLineValue = null;
    protected static String sErrrorFile = null;

    private static ArrayList sample=new ArrayList();
    
    static boolean bError; // true if there is any error in the entire validation process

    public static void main(String[] args)
    {
  boolean bFileRead = true;
     if (null == sCSVFile)
         sCSVFile = "D:/csvread/sample.csv";
        System.out.println("sCSVFile - "+sCSVFile);
        // Read the Tier file into array lists
        System.out.println("Run - 1 : Reading the CSV file : "+sCSVFile);
        bFileRead = readCSV();
        System.out.println("Run - 2 : bFileRead: "+bFileRead);
        System.out.println("Run - 3 : bError: "+bError);

        if (bFileRead)
        {
    try {
     System.out.println("Run - 4 : CSV file has been read successfully and can be referenced through alCSVLineValue-HashMap");
   } catch (Exception e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
   }
  }
 }
    /*
     readCSV(): This method reads the CSV file into an arraylist/HashMap
    */
    protected static boolean readCSV ()
    {
  boolean bFileReadSucess = true;
  String sExceptionIfAny = null;
  String sLineRead = null;
  alUniqueKey = new ArrayList();
  alCSVLineValue = new HashMap();
        
  String sBreakCharacters = ",";
  String sUniqueName=null;
  
  System.out.println("inside csv file read");

  try
  {
   RandomAccessFile rafTierCSVFile = new RandomAccessFile(sCSVFile, "r");

   int iLineCount = 0;
   int indexCount=0;
   String sLineCount = null;
   // Read the file line by line
   while ((sLineRead = rafTierCSVFile.readLine()) != null)
   {
    ArrayList eachLine=new ArrayList();
    ArrayList eachValue=new ArrayList();
    
    iLineCount++;
    sLineCount = String.valueOf(iLineCount);
    sLineRead = sLineRead.trim();
    System.out.println("inside csv file read2");
    System.out.println(sLineRead);

    StringTokenizer st = new StringTokenizer(sLineRead,sBreakCharacters);
    // Skip the record if it does not have 8 fields
    System.out.println(st.countTokens());
    if ((st.countTokens()-1) != 7 )//This validation is used ONLY when the length of each row is already known;else it can be skipped
    {
     System.out.println ("No. of columns in a row is incorrect");
     bError = true;
     System.out.println(sLineCount+"["+st.countTokens()+"], ");

     continue;
    }
    System.out.println("Delimiter checked");
    // convert delimited string into vector of strings
    
    while (st.hasMoreTokens())
    {
     
     //get next token and store it in the array
     eachLine.add(st.nextToken());
         
    }
               
                System.out.println ("ArrayList created: ");
                // remove quotes if the cav contains values enclosed within double-quotes
                
    sUniqueName = removeQuotes(((String)eachLine.get(0)).trim());//assuming that the 1st value is the UniqueKey

    System.out.println ("readTierCSV - 1: sUniqueName: " + sUniqueName);
    //similarly other values of the line/row can be read

    for(int z=0;z<eachLine.size();z++)
          {
     System.out.println("inside the row");
     eachValue.add(removeQuotes(((String)eachLine.get(z)).trim()));
     
     //System.out.println("row"+z+removeQuotes(((String)eachLine.get(z)).trim()));
     
          }
    FastStringBuffer fsbNullValue = new FastStringBuffer();
    // Check for null values
    fsbNullValue.append((StringUtil.nullOrEmptyOrBlankString(sUniqueName) ? " UniqueName " : ""));
    // similarly other values can be null checked
    
    if (fsbNullValue.length() > 0)
    {
     bError = true;
     fsbNullValue.append("Line#"+sLineCount.toString());
     System.out.println("readTierCSV - 2: NullValue: " + fsbNullValue.toString());
     fsbNullValue.append("
");
     
    }
    else
    {
     alCSVLineValue.put(sUniqueName,eachValue);
     alUniqueKey.add(sUniqueName);
    }

   }
//    build a Hashmap with any one Uniquekey so that the corresponding row can be retrieved based on a UniqueKey
   
   
   for(int z=0;z<alUniqueKey.size();z++)
         {
    System.out.println("inside HashMap");
    System.out.println(alCSVLineValue.get(alUniqueKey.get(z)));
    sample=((ArrayList)alCSVLineValue.get(alUniqueKey.get(z)));
    for(int h=0;h<sample.size();h++)
          {
    System.out.println(sample.get(h));
          }
         }
   rafTierCSVFile.close();
   
  }
  
  catch (FileNotFoundException fnfExp)
  {
   bFileReadSucess = false;
   sExceptionIfAny = fnfExp.getMessage();
  }
  catch(IOException ioExp)
  {
   bFileReadSucess = false;
   sExceptionIfAny = ioExp.getMessage();
  }
  catch(Exception exp)
  {
   bFileReadSucess = false;
   sExceptionIfAny = exp.getMessage();
  }
  finally
  {
   
   if (!bFileReadSucess)
   {
    bError = true;
    System.out.println ("readTierCSV - 2: Error opening file: " + sCSVFile);
    System.out.println ("readTierCSV-3: Error opening file - Exception: " + sExceptionIfAny);

   }
   return bFileReadSucess;
  }
 }


 


 /*
 This method removes double quotes from the beginingand end of a string
 This was added to handle the special case where a particular field contained double quotes
 */
 protected static String removeQuotes(String sField)
 {
  System.out.println("removeQuotes - 1: incoming sField: "+sField);
  String sQuotes = """;
  if (sField != null)
  {
   sField = (sField.startsWith(sQuotes)) ? (sField.substring(1)) : sField;
   //System.out.println("removeQuotes - 2: sField after removing first double quotes: "+sField);
   sField = (sField.endsWith(sQuotes)) ? (sField.substring(0, (sField.length()-1))) : sField;
   //System.out.println("removeQuotes - 3: sField after removing second double quotes: "+sField);
  }
  //System.out.println("removeQuotes - 4: returning sField: "+sField);
  return sField;
 }
}