Entity and Worker Class for developing project

While developing projects it is important that we work with some simple model so that code can be reused rather than re coded.

Structure of Worker Model

Now as the image shows the flow. Let us create a Worker class for Customer.
So my table customer looks like this

Structure of Customer Table

• Now as our database table is ready we can develop our Entity class in this case it is Customer.java 
• Entity Class basically contains the fields of the Entity and its setter and getter methods.

For example.

email is a field in Customer file hence we have methods by name getEmail() and setEmail()

Customer.java

public class Customer
 {
    int id;
    String fname,mname,lname,address,contact,email,password,dor,company,title;

    public Customer() {
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getFname() {
        return fname;
    }

    public void setFname(String fname) {
        this.fname = fname;
    }

    public String getMname() {
        return mname;
    }

    public void setMname(String mname) {
        this.mname = mname;
    }

    public String getLname() {
        return lname;
    }

    public void setLname(String lname) {
        this.lname = lname;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public String getContact() {
        return contact;
    }

    public void setContact(String contact) {
        this.contact = contact;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getDor() {
        return dor;
    }

    public void setDor(String dor) {
        this.dor = dor;
    }

    public String getCompany() {
        return company;
    }

    public void setCompany(String company) {
        this.company = company;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }
   
   
}
 

Now the last and important step in developing of this model is Worker file. 

1. Now i will name the worker as EntityWorker.java with three important methods    

• addEntity(Entity e) 
• updateEntity(Entity e) 
• deleteEntity(int id)

So as per the model  my worker will be named as CustomerWorker.java and methods would be

• addCustomer(Customer c) 
• updateCustomer(Customer c) 
• deleteCustomer(int id)

Now let us go in deep and understand a single method

Method will return String based on which we decide the flow.

public static String addCustomer(Customer c)
            {
                String result="";
                try
                {
                    String query="Insert into customer(title,fname,mname,lname,address,company,email,password,contact,dor) values (?,?,?,?,?,?,?,?,?,?);";
---> I have used the PreparedStatement here and to understand what is DatabaseConnector click on it.
Got all the data from customer object and set it in pstmt object and executed it.<---                    
PreparedStatement pstmt=DatabaseConnector.getPreparedStatement(query);
                    pstmt.setString(1,c.getTitle());
                    pstmt.setString(2,c.getFname());
                    pstmt.setString(3,c.getMname());
                    pstmt.setString(4,c.getLname());
                    pstmt.setString(5,c.getAddress());
                    pstmt.setString(6,c.getCompany());
                    pstmt.setString(7,c.getEmail());
                    pstmt.setString(8,c.getPassword());
                    pstmt.setString(9,c.getContact());
                    pstmt.setString(10,c.getDor());
                   
                        int i=pstmt.executeUpdate();

               
                    if(i==1)
                {
                    result="SUCCESS";
                }
                else
                {
                    result="FAIL";
                }


        }
        catch (Exception e)
        {
            result="PROBLEM";
            e.printStackTrace();
        }

        return result;
 
    }
So the overall CustomerWorker .java file will look like this.

CustomerWorker.java

import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.Statement;

public class CustomerWorker 
{
    public static String addCustomer(Customer c)
            {
                String result="";
                try
                {
                    String query="Insert into customer(title,fname,mname,lname,address,company,email,password,contact,dor) values (?,?,?,?,?,?,?,?,?,?);";
                    PreparedStatement pstmt=DatabaseConnector.getPreparedStatement(query);
                    pstmt.setString(1,c.getTitle());
                    pstmt.setString(2,c.getFname());
                    pstmt.setString(3,c.getMname());
                    pstmt.setString(4,c.getLname());
                    pstmt.setString(5,c.getAddress());
                    pstmt.setString(6,c.getCompany());
                    pstmt.setString(7,c.getEmail());
                    pstmt.setString(8,c.getPassword());
                    pstmt.setString(9,c.getContact());
                    pstmt.setString(10,c.getDor());
                   
                        int i=pstmt.executeUpdate();

               
                    if(i==1)
                {
                    result=Results.SUCCESS;
                }
                else
                {
                    result=Results.FAIL;
                }


        }
        catch (Exception e)
        {
            result=Results.PROBLEM;
            e.printStackTrace();
        }

        return result;
           
       
    }
   
   
    public static String updateCustomer(Customer c)
    {
       
                String result="";
                try
                {
                    String query="Update customer set title=?,fname=?,mname=?,lname=?,address=?,company=?,email=?,password=?,contact=?,dor=? where id=?;";
                   
                    PreparedStatement pstmt=DatabaseConnector.getPreparedStatement(query);
                    pstmt.setString(1,c.getTitle());
                    pstmt.setString(2,c.getFname());
                    pstmt.setString(3,c.getMname());
                    pstmt.setString(4,c.getLname());
                    pstmt.setString(5,c.getAddress());
                    pstmt.setString(6,c.getCompany());
                    pstmt.setString(7,c.getEmail());
                    pstmt.setString(8,c.getPassword());
                    pstmt.setString(9,c.getContact());
                    pstmt.setString(10,c.getDor());
                    pstmt.setInt(11,c.getId());
                   
                        int i=pstmt.executeUpdate();

               
                    if(i==1)
                {
                    result=Results.SUCCESS;
                }
                else
                {
                    result=Results.FAIL;
                }


        }
        catch (Exception e)
        {
            result=Results.PROBLEM;
            e.printStackTrace();
        }

        return result;
           
    }
   
    public static String deleteCustomer(int id)
    {
            String result="";
                try
                {
                    String query="Delete from customer where id=?;";
                   
                    PreparedStatement pstmt=DatabaseConnector.getPreparedStatement(query);
                     pstmt.setInt(1,id);
                   
                        int i=pstmt.executeUpdate();

               
                    if(i==1)
                {
                    result=Results.SUCCESS;
                }
                else
                {
                    result=Results.FAIL;
                }


        }
        catch (Exception e)
        {
            result=Results.PROBLEM;
            e.printStackTrace();
        }

        return result;
    }
   
      public static String checkLogin(String user,String password)
    {
        String result="";
        String dbUser="",dbPass="";
        try {
            Statement st=DatabaseConnector.getStatement();
            String query="Select email from customer where email like '"+user+"' and password like '"+password+"'; " ;
           ResultSet rs=st.executeQuery(query);
        if( rs.next())
        {
   
            result=Results.SUCCESS;
        }
        else
        {
            result=Results.FAIL;
        }
        }
        catch (Exception e)
        {

            result=Results.PROBLEM;
            e.printStackTrace();
        }
       
        return result;
    }
   
}
 

CustomerWorker will have these 3 as well as additional methods for in later part.

These model can be used in both Desktop as well as Web Projects in Java.