list error

[tyte kyat]

Hi, I got a question regarding about list and iterator.

the problem is I got a list of type customer return from DataBase.
inside that list there are two elements customer_id and username.

how do I get that customer_id and username element out of the list?
even though I iterate it, it seem does not work.

Thanks in advance.

e.g in my DAO class I got the following

public List<Customer> loginCustomer(String name, String password) {
		List<Customer> customerlist=null;
		String querystring="Select id ,type from Customer where Customer.name='"+name+"'and Customer.password='"+password+"'";
		
		try {
			customerlist=session.createSQLQuery(querystring).list();
		} catch (Exception e) {
			e.printStackTrace();
		}
		
		return customerlist;
	}

in my business class I got the following

System.out.println("customer list size="+customerlist.size());
					System.out.println("list iterated"+customerlist.iterator().next());

[Seetharaman Venkatasamy]

1.you have List of Customer

2.you have to get all the customers from the List. how do you do? you need an iterator
then you need to check any more Customer object is in list or not . how do you do this using hasNext() method of that iterator.

3. if any object is there you need to get one by one by using Iterator#next()

4. now you have a Customer object in your hand. you know how to get the properties for the object? using getters?

[Steve Luke]

You will have to look at the Customer class and see what methods it has for getting that data out. Does it have getID() and getUserName() for example? This is something we can't answer without having access to the Customer class.

[Kunal Lakhani]

What's the error?

With the Iterator you can get the Customer object. Use getters methods to get the data.

I am not sure whether enhanced for loop work in place of Iterator? Give your valuable suggestions

[tyte kyat]

yes I do have getter and setter as follow

package com.myauk.model;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name="CUSTOMER")
public class Customer {
	
	private int id;
	private String name;
	private String address;
	private String telephone;
	private String password;
	private String type;
	private String email;
	
	@Id
	@GeneratedValue
	@Column(name="ID")
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
	
	@Column(name="NAME")
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	
	@Column(name="ADDRESS")
	public String getAddress() {
		return address;
	}
	public void setAddress(String address) {
		this.address = address;
	}
	
	@Column(name="TELEPHONE")
	public String getTelephone() {
		return telephone;
	}
	public void setTelephone(String telephone) {
		this.telephone = telephone;
	}
	
	@Column(name="PASSWORD")
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
	
	@Column(name="TYPE")
	public String getType() {
		return type;
	}
	public void setType(String type) {
		this.type = type;
	}
	
	@Column(name="EMAIL")
	public String getEmail() {
		return email;
	}
	public void setEmail(String email) {
		this.email = email;
	}
	
	

}

[tyte kyat]

Thanks Kunal, Steve and Seetharaman
I got the idea and solved it out now

the reason is I did not create an Object at first and the second is where I do in my DAOImpl class I have to modified it as follow.

customerlist=session.createSQLQuery(querystring).addEntity(Customer.class).list();

instead of using

customerlist=session.createSQLQuery(querystring).list();  

thanks you all

[Kunal Lakhani]

You can also use criteria api. That's simple and you don't need to embed SQL query.