risk_mgnt_manager.StressCSVLoader.java Source code

Introduction

Here is the source code for risk_mgnt_manager.StressCSVLoader.java

Source

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */

package risk_mgnt_manager;

import java.io.FileNotFoundException;
import java.io.FileReader;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.util.Date;

import org.apache.commons.lang3.StringUtils;

import au.com.bytecode.opencsv.CSVReader;

/*
 * @author mLaMeyer
 */
public class StressCSVLoader {
    private static final String SQL_INSERT = "INSERT INTO ${table}(${keys}) VALUES(${values})";
    private static final String TABLE_REGEX = "\\$\\{table\\}";
    private static final String KEYS_REGEX = "\\$\\{keys\\}";
    private static final String VALUES_REGEX = "\\$\\{values\\}";

    private Connection connection;
    private char seprator;

    /**
     * Public constructor to build CSVLoader object with
     * Connection details. The connection is closed on success
     * or failure.
     * @param connection
     */
    public StressCSVLoader(Connection connection) {
        this.connection = connection;
        //Set default separator
        this.seprator = ',';
    }

    /**
     * Parse CSV file using OpenCSV library and load in 
     * given database table. 
     * @param csvFile Input CSV file
     * @param tableName Database table name to import data
     * @throws Exception
     */
    public void loadCSV(String csvFile, String tableName, String filename) throws Exception {

        CSVReader csvReader = null;
        if (null == this.connection) {
            throw new Exception("Not a valid connection.");
        }
        try {
            csvReader = new CSVReader(new FileReader(csvFile), this.seprator);

        } catch (Exception e) {
            e.printStackTrace();
            throw new Exception("Error occured while executing file. " + e.getMessage());
        }

        String[] headerRow = csvReader.readNext();

        if (null == headerRow) {
            throw new FileNotFoundException(
                    "No columns defined in given CSV file." + "Please check the CSV file format.");
        }

        String questionmarks = StringUtils.repeat("?,", headerRow.length);
        questionmarks = (String) questionmarks.subSequence(0, questionmarks.length() - 1);
        String col_Names = "Point_in_Time, Portfolio, Fut_Variation, Opt_Variation, Total_Variation, Percent_of_Ledger_Balance, Ledger_Balance";

        String query = SQL_INSERT.replaceFirst(TABLE_REGEX, tableName);
        //query = query.replaceFirst(KEYS_REGEX, StringUtils.join(headerRow, ","));
        query = query.replaceFirst(KEYS_REGEX, col_Names);
        query = query.replaceFirst(VALUES_REGEX, questionmarks);

        String update = "UPDATE mgex_riskmgnt." + tableName + " SET Imported_File_Name = '" + filename + "' Where "
                + "Imported_File_Name IS NULL";

        System.out.println("Query: " + query);
        System.out.println("Update: " + update);

        String[] nextLine;
        Connection con = null;
        Connection con2 = null;
        PreparedStatement ps = null;
        PreparedStatement ps2 = null;
        try {
            con = this.connection;
            con.setAutoCommit(false);
            ps = con.prepareStatement(query);

            con2 = this.connection;
            con2.setAutoCommit(false);
            ps2 = con2.prepareStatement(update);

            final int batchSize = 1000;
            int count = 0;
            Date date = null;
            while ((nextLine = csvReader.readNext()) != null) {

                if (null != nextLine) {
                    int index = 1;
                    for (String string : nextLine) {
                        //date = DateUtill.convertToDate(string);
                        if (null != date) {
                            ps.setDate(index++, new java.sql.Date(date.getTime()));
                        } else {
                            ps.setString(index++, string);
                        }
                    }
                    ps.addBatch();
                }
                if (++count % batchSize == 0) {
                    ps.executeBatch();
                }
            }
            ps.executeBatch(); // insert remaining records
            ps2.executeUpdate();
            con.commit();
            con2.commit();
        } catch (Exception e) {
            con.rollback();
            con2.rollback();
            e.printStackTrace();
            throw new Exception("Error occured while loading data from file to database." + e.getMessage());
        } finally {
            if (null != ps)
                ps.close();
            ps2.close();
            if (null != con)
                con.close();
            con2.close();

            csvReader.close();
        }
    }

    public char getSeprator() {
        return seprator;
    }

    public void setSeprator(char seprator) {
        this.seprator = seprator;
    }
}