some random shit

package com;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;

public class EmployeeManagementDAO {
    private String connectionString = "jdbc:oracle:thin:@172.24.137.13:1521:XE";
    private String userName = "JE";
    private String password = "JE";
    private String driver = "oracle.jdbc.driver.OracleDriver";
    private Connection con;
    private PreparedStatement ps;

    public int addEmployee(EmployeeBean e){
        int result = 0;
        try{
            Class.forName(driver);

            con = DriverManager.getConnection(connectionString, userName, password);

            String query = "INSERT INTO TBL_1437159_EMP(EMP_ID, EMP_NAME, AGE, LG_ID) " +
                                " VALUES(?,?,?,?)";

            ps = con.prepareStatement(query);

            if(ps!=null){
                ps.setInt(1, e.getEmpId());
                ps.setString(2, e.getEmpName());
                ps.setInt(3, e.getAge());
                ps.setInt(4, e.getLgId());
            }

            result = ps.executeUpdate();

        }catch (ClassNotFoundException ce) {
            result = 0;
        }catch (SQLException se) {
            result = 0;
        }finally{
            try{
                if(con != null){
                    con.close();
                }
                if(ps != null){
                    ps.close();
                }
            }catch (SQLException se) {
                result = 0;
            }
        }
        return result;
    }

    public ArrayList<EmployeeBean> getEmployeesBasedOnAge(int from, int to){
        ArrayList<EmployeeBean> result = new ArrayList<EmployeeBean>();

        try{
            Class.forName(driver);

            con = DriverManager.getConnection(connectionString, userName, password);

            String query = "SELECT * FROM TBL_1437159_EMP " +
                                "WHERE AGE BETWEEN ? AND ?";

            ps = con.prepareStatement(query);

            if(ps!=null){
                ps.setInt(1, from);
                ps.setInt(2, to);
            }

            ResultSet rs = ps.executeQuery();

            while(rs.next()){
                EmployeeBean temp = new EmployeeBean();
                temp.setEmpId(rs.getInt("EMP_ID"));
                temp.setEmpName(rs.getString("EMP_NAME"));
                temp.setAge(rs.getInt("AGE"));
                temp.setLgId(rs.getInt("LG_ID"));
                result.add(temp);
            }

        }catch (ClassNotFoundException ce) {
            result = null;
        }catch (SQLException se) {
            result = null;
        }finally{
            try{
                if(con != null){
                    con.close();
                }
                if(ps != null){
                    ps.close();
                }
            }catch (SQLException se) {
                result = null;
            }
        }

        return result;
    }



    public ArrayList<Integer> getBatchNumbers(){
        ArrayList<Integer> result = new ArrayList<Integer>();

        try{
            Class.forName(driver);

            con = DriverManager.getConnection(connectionString, userName, password);

            String query = "SELECT BATCH_NUM FROM TBL_1437159_LG SORT BY BATCH_NUM DESC";

            ps = con.prepareStatement(query);

            ResultSet rs = ps.executeQuery();

            while(rs.next()){
                result.add(rs.getInt("BATCH_NUM"));
            }

        }catch (ClassNotFoundException ce) {
            result = null;
        }catch (SQLException se) {
            result = null;
        }finally{
            try{
                if(con != null){
                    con.close();
                }
                if(ps != null){
                    ps.close();
                }
            }catch (SQLException se) {
                result = null;
            }
        }
        return result;
    }


    public int getAvrageAge(String criteria){
        int result = 0;
        try{
            Class.forName(driver);

            con = DriverManager.getConnection(connectionString, userName, password);

            String query = "SELECT AVG(AGE) AS AVERAGE_AGE FROM TBL_1437159_EMP " +
                    " WHERE EMP_NAME LIKE ?%";

            ps = con.prepareStatement(query);

            if(ps!=null){
                ps.setString(1, criteria);
            }

            ResultSet rs = ps.executeQuery();

            while(rs.next()){
                result = rs.getInt("AVERAGE_AGE");
            }

        }catch (ClassNotFoundException ce) {
            result = 0;
        }catch (SQLException se) {
            result = 0;
        }finally{
            try{
                if(con != null){
                    con.close();
                }
                if(ps != null){
                    ps.close();
                }
            }catch (SQLException se) {
                result = 0;
            }
        }
        return result;
    }

}