declare dynamic variable names

[gwu]

How do I declare dynamic variable names so I can use the people class multiple times. Is there a better approach with Java to what I am doing. Thanks.

************************
person person0 = new person(rs.getString(1));
person person1 = new person(rs.getString(1));
person person3 = new person(rs.getString(1));
....
person person[n] = new person(rs.getString(1));
************************
This is how it is done in actionscript, I just concat "person" and the variable myNumber:

["person"+myNumber] = "somedata"
*************************

//declare the person class
public class person{
String lastName;

public person(String lastName){
this.lastName = lastName;

}
}

//Then I get the data from sql and put it into the class:

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
int myNumber = 0;
String dbURL = "jdbcdbc:*****";
try {
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
}catch (ClassNotFoundException e) {
System.out.println("Database access failed " + e);
}
try {
Connection conn = DriverManager.getConnection(dbURL,"*****","****");
Statement stmt=conn.createStatement();
//ResultSet rs=stmt.executeQuery("select firstName from GetConReg where lastName='"+jTextField1.getText()+"'");
ResultSet rs=stmt.executeQuery("select firstName from GetConReg where lastName != ''");
while(rs.next()){
person ["person"+myNumber] = new person(rs.getString(1));
System.out.println(["person"+myNumber].lastName);
myNumber++;
}
}catch (SQLException e) {
System.out.println("Database access failed " + e);
}
}
************************

 

[sedj]

I can't see that compiling ...
(especially this line erson ["person"+myNumber] = new person(rs.getString(1));
)

Try adding your person objects into a class variable ArraList ...

import java.util.*;

public class Whatever {
  private ArrayList people  = new ArrayList();

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
        int myNumber = 0;
        String dbURL = "jdbc:odbc:*****";
        try {
            Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
        }catch (ClassNotFoundException e) {
            System.out.println("Database access failed " + e);
        }
        try {
            Connection conn = DriverManager.getConnection(dbURL,"*****","****");
            Statement stmt=conn.createStatement();
            //ResultSet rs=stmt.executeQuery("select firstName from GetConReg where lastName='"+jTextField1.getText()+"'");
            ResultSet rs=stmt.executeQuery("select firstName from GetConReg where lastName != ''");
            while(rs.next()){
               people.add(new person(rs.getString(1)));
        System.out.println(["person"+myNumber].lastName);
                myNumber++;
            }
        }catch (SQLException e) {
            System.out.println("Database access failed " + e);
        }
    }
}

 

[gwu]

Here is the final code but I am getting this message:

Database access failed java.sql.SQLException: No data found
JFrame_1$person@76fba0

I know this is not a database error because when I take this line out:

people.add(myNumber, new person(rs.getString(1)));

, I do not get the error. There is no problem with databse or the data within it.

thanks

public class person{
    String lastName;
    
    public person(String lastName){
        this.lastName = lastName;
    }
}

public ArrayList people  = new ArrayList();
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
        int myNumber = 0;
        String dbURL = "jdbc:odbc:****";
        try {
            Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
        }catch (ClassNotFoundException e) {
            System.out.println("Database access failed " + e);
        }
        try {
            Connection conn = DriverManager.getConnection(dbURL,"******","***");
            Statement stmt=conn.createStatement();
            ResultSet rs=stmt.executeQuery("select firstName,lastName from GetConReg where lastName like '"+jTextField1.getText()+"%'");
            while(rs.next()){
                people.add(myNumber, new person(rs.getString(1)));
                myNumber++;
            }
            
        }catch (SQLException e) {
            System.out.println("Database access failed " + e);
        }
        System.out.println(people.get(0));
      
    }

 

[sedj]

It is a database problem ... run this code, and you'll see :

public class person{
    String lastName;
    
    public person(String lastName){
        this.lastName = lastName;
    }
}

public ArrayList people  = new ArrayList();
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
        int myNumber = 0;
        String dbURL = "jdbc:odbc:****";
        try {
            Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
        }catch (ClassNotFoundException e) {
            System.out.println("Database access failed " + e);
        }
        try {
            Connection conn = DriverManager.getConnection(dbURL,"******","***");
            Statement stmt=conn.createStatement();
            ResultSet rs=stmt.executeQuery("select firstName,lastName from GetConReg where lastName like '"+jTextField1.getText()+"%'");
            while(rs.next()){
               System.out.println("about to request data ... " +myNumber);
                String qqq = rs.getString(1);
                System.out.println("Data - " +myNumber +" : " +qqq);
                people.add(myNumber, new person(qqq));
                myNumber++;
            }
            
        }catch (SQLException e) {
            System.out.println("Database access failed " + e);
        }
        System.out.println(people.get(0));
      
    }