Simple Csv Parser Example with POJO Class

Simple CSV parsing example with POJO class.

Copy below classes to appropriate folders and run the class CsvParserExample. 

Employee.java - com/csvparsing/pojo
CsvParserExample - com/csvparsing
ParseHelper -  com/csvparsing/common

employee.csv - com/csvparsing

Employee POJO,

package com.csvparsing.pojo;


/**
 * @author Sharoon
 *
 */
public class Employee {
   
    private int id;
    private String name;
    private String dob;
   
   
    public Employee(int id, String name,String dob){
        this.id = id;
        this.name = name;
        this.dob = dob;
    }
   
    public Employee() {
    }

    /**
     * @return the id
     */
    public int getId() {
        return id;
    }
    /**
     * @param id the id to set
     */
    public void setId(int id) {
        this.id = id;
    }
    /**
     * @return the name
     */
    public String getName() {
        return name;
    }
    /**
     * @param name the name to set
     */
    public void setName(String name) {
        this.name = name;
    }
    /**
     * @return the dob
     */
    public String getDob() {
        return dob;
    }
    /**
     * @param string the dob to set
     */
    public void setDob(String dob) {
        this.dob = dob;
    }

}


Main Class CsvParserExample,

package com.csvparsing;

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.lang.reflect.Field;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

import com.csvparsing.common.ParseHelper;
import com.csvparsing.pojo.Employee;

/**
 *
 * @author Sharoon
 *
 */
public class CsvParserExample {

    /**
     * @param args
     */
    public static void main(String[] args) {
       
        // Reading employee List
        List resultList = getEmployeeList();
        formatAndDisplay(resultList);
       
        // Insert a record into employee List
        Employee newEmployee = new Employee();
        newEmployee.setId(11);
        newEmployee.setName("Vijay");
        newEmployee.setDob("14/05/1985");
       
        insertEmployeee(newEmployee);
       
    }

    private static void insertEmployeee(Employee newEmployee) {
        try {
            FileWriter pw = new FileWriter("src/com/csvparsing/employees.csv",true);
           
            if(newEmployee !=null){
                pw.append(String.valueOf(newEmployee.getId()));
                pw.append(",");
                pw.append(newEmployee.getName());
                pw.append(",");
                pw.append(newEmployee.getDob().toString());               
                pw.append("\n");
            }
             pw.flush();
             pw.close();
           
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * Method to get the list of people by their name
     * @param string
     * @return
     */
    public static List<Object> getEmployeeList() {
        Employee employee = new Employee();
        return processRecordsFromCSV("employees.csv", employee);
    }

    public static List<Object> processRecordsFromCSV(String fileName, Object record) {
        List<Object> recordList = new ArrayList<Object>();
           try{
                   String path = "src/com/csvparsing/"+fileName;
                BufferedReader br = new BufferedReader( new FileReader(path));
                String strLine = "";
               
                String[] columns = ParseHelper.getColumns(br);
                while((strLine = br.readLine()) != null){
                    Object newRecord = record.getClass().newInstance();
                    String[] values = strLine.split(",");
                    int size = values.length;
                    if(columns.length != size)
                        continue;
                   
                    for(int i=0;i< size;i++){
                        String columnName = columns[i];
                        Field f1 = record.getClass().getDeclaredField(columnName);
                        f1.setAccessible(true);
                        f1.set(newRecord, getTypedValue(f1.getType(),values[i]));
                    }
                    recordList.add(newRecord);
                }
                br.close();
            } catch(Exception e){
                    System.out.println("Exception occured while parsing CSV file : " + e);                 
            }
           
            return recordList;
    }
   
   
    /**
     * Method to get typed value
     * @param type
     * @param value
     * @return
     */
    private static Object getTypedValue(Class<?> type, String value) {
        Object typedValue = null;
        if(type == int.class){
            value = !"".equals(value)?value:"0";
            typedValue = Integer.parseInt(value);
        } else if(type == Date.class){
            DateFormat formatter = new SimpleDateFormat("dd/MM/yyyy");               
            try {
                typedValue = (Date)(formatter.parse(value));
            } catch (ParseException e) {
                e.printStackTrace();
            }
        } else if(type == Double.class){
            value = !"".equals(value)?value:"0.0";
            typedValue = Double.parseDouble(value);
        } else if(type == Float.class){
            value = !"".equals(value)?value:"0.0f";
            typedValue = Double.parseDouble(value);
        } else if(type == boolean.class){
            value = !"".equals(value)?value:"0.0f";
            typedValue = Boolean.parseBoolean(value);
        } else if(type == String.class){
            typedValue = value;
        }
        return typedValue;
    }   
    /**
     *
     * @param employeeList
     */
    public static void formatAndDisplay(List<Employee> employeeList) {
        System.out.println(" ##  - Employee Records - ##");
        System.out.println("Id \t"+"|"+"Name\t"+"|"+"|"+"DOB");
        for(Employee employee:employeeList){
            System.out.print(employee.getId()+"\t"+"|");
            System.out.print(employee.getName()+"\t"+"|");
            System.out.print(employee.getDob());
            System.out.println();
        }
       
    }

}

ParseHelper Class to get Columns and its count.


package com.csvparsing.common;

import java.io.BufferedReader;
import java.io.IOException;
import java.util.StringTokenizer;

/**
 * @author Sharoon
 *
 */
public class ParseHelper {

    public static int NO_OF_COLUMNS = 0;
   
    public static String[] getColumns(BufferedReader br) {
       
        String record = "";
        StringTokenizer st = null;
        String[] columns = null;
       
        try {
            if((record = br.readLine()) != null){
                st = new StringTokenizer(record, ",");
                columns = new String[st.countTokens()];
                while(st.hasMoreTokens())
                {
                   
                    columns[NO_OF_COLUMNS] = st.nextToken();
                    NO_OF_COLUMNS++;
                }               
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return columns;
    }
      

}


Csv File employee.csv