I want to display all the data in my console from the data base using ArrayList

Question

Hello all i want is to display entire content of my database table on Console. I am trying to fetch record from database first and store in ArrayList but it does not display any thing insted it display this:

[com.suven.java.EmployeeDTO@970c0e]
[com.suven.java.EmployeeDTO@970c0e, com.suven.java.EmployeeDTO@987197] 
[com.suven.java.EmployeeDTO@970c0e, com.suven.java.EmployeeDTO@987197, com.suven.java.EmployeeDTO@497904]

I am fully confused to what to do. My code is:

EmployeeDTO java file

public class EmployeeDTO 
{
    //private properties
    private int empNo;
    private String eName;
    private String jobTitle;
    //setters
    public void setEmpNo(int val){empNo=val;}
    public void setEName(String val){eName=val;}
    public void setJob(String val){jobTitle=val;}
    // getters
    public int getEmpNo(){return empNo;}
    public String getEName(){return eName;}
    public String getJob(){return jobTitle;}
}

My EmployeeList java code is:

public class EmployeeList 
{

  public static void main(String argv[]) 
  {
   Connection conn=null;
   Statement stmt=null;
   ResultSet rs=null;      

   try 
   {
    // Load the JDBC driver  
    // This can be skipped for Derby, but derbyclient.jar has to be in the CLASSPATH   
    Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
    String accessFileName = "E:/Database/java";
    conn=DriverManager.getConnection("jdbc:odbc:DRIVER={Microsoft Access  Driver (*.mdb, *.accdb)};DBQ="+accessFileName+".accdb;");

    // Build an SQL String 
    String sqlQuery = "SELECT * from Employee"; 

    // Create a Statement object
    stmt = conn.createStatement(); 

    // Execute SQL and get obtain the ResultSet object
    rs = stmt.executeQuery(sqlQuery);  
    ArrayList<EmployeeDTO> employees = new ArrayList<EmployeeDTO>();
    // Process the result set - print Employees
    while (rs.next())
    { 
        EmployeeDTO currentEmp = new EmployeeDTO();

        currentEmp.setEmpNo(rs.getInt("EMPNO"));
        currentEmp.setEName(rs.getString("ENAME"));
        currentEmp.setJob(rs.getString("JOB_TITLE"));
        employees.add(currentEmp);
        System.out.println(employees);
    }       
   } 
   catch( SQLException se ) 
   {
      System.out.println ("SQLError: " + se.getMessage ()+ " code: " + se.getErrorCode ());
   }
   catch( Exception e )
   {
      System.out.println(e.getMessage());
      e.printStackTrace(); 
   }
   finally
   {
       // clean up the system resources
       try
       {
       rs.close();     
       stmt.close(); 
       conn.close();  
       }
       catch(Exception e)
       {
           e.printStackTrace();
       } 
   }
}
}

My database is:

Employee
EMPN     ENAME     JOB_TITLE
1        abc       xyz
2        pqr       mno
3        lmn       hij

Please help me i have posted my full code and database where am i going wrong how to display it in a console

Answer 1

You have to implement toString() in your EmployeeDTO class. If you are using Eclipse you can generate the method: right click the class -> Source -> Generate toString()...

Answer 2

You need to override toString in your EmployeeDTO class. You could use String.format to do the formatting:

@Override
public String toString() {
   return String.format("%d\t%s\t%s", empNo, eName, jobTitle);
}

To print each employee on a separate line you could use:

for (EmployeeDTO employee : employees) {
    System.out.println(employee);
}

Answer 3

ArrayList<EmployeeDTO> employees = new ArrayList<EmployeeDTO>();
// Process the result set - print Employees
while (rs.next())
{ 
    EmployeeDTO currentEmp = new EmployeeDTO();

    currentEmp.setEmpNo(rs.getInt("EMPNO"));
    currentEmp.setEName(rs.getString("ENAME"));
    currentEmp.setJob(rs.getString("JOB_TITLE"));
    employees.add(currentEmp);
    System.out.println(employees);
}       

In this code, you are putting Object into ArrayList, not an actual String/Value into it. That's why you are getting as com.suven.java.EmployeeDTO@970c0e

Answer 4

Looks like you need an implementation of toString() in your DTO. You'd implement that such that it returns a string consisting of your employee name, job etc... Here's a link to 10 tips for implementing toString() .

I note also that you print the list of employees after you read each employee. I suspect rather that you need to print the employee itself.

System.out.println(employees); // this is the list itself!

Answer 5

You are doing it all right except in the line

System.out.println(employees);

in the while loop.

You cannot display ArrayList like that with out overloading toString() in your EmployeeDTO class.

Instead, to display array list, do this after the while loop

for(EmployeeDTO emp : employees)
{
    System.out.println(emp.getEmpNo() + " " +  emp.getEName() + " " + emp.getJob());
}