package com.ibm.ta.dao.db2;

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

import com.ibm.ta.dao.StudentDAO;
import com.ibm.ta.dao.DAOException;
import com.ibm.ta.dao.DAOParameterException;
import com.ibm.ta.dao.DAOUtil;
import com.ibm.ta.webservice.Student;

public class DB2StudentDAO implements StudentDAO {
	private DB2DAOFactory factory;

	public DB2StudentDAO(DB2DAOFactory factory) {
		this.factory = factory;
	}

	public Student[] selectStudents() throws DAOException {
		Connection con = null;
		PreparedStatement ps = null;
		ResultSet rs = null;
		List results = new ArrayList();

		try {
			con = factory.createConnection();

			ps = con
					.prepareStatement("SELECT student_id, student_name from ta.STUDENT");
			rs = ps.executeQuery();
			while (rs.next()) {
				Student student = new Student(rs.getLong(1), rs.getString(2));
				results.add(student);
			}
		} catch (SQLException sqle) {
			throw new DAOException(sqle.getMessage(), sqle);
		} finally {
			DAOUtil.closeResources(rs, ps, null, con);
		}
		return (Student[]) results.toArray(new Student[results.size()]);
	}

	public void insertStudent(String name) throws DAOException,
			DAOParameterException {
		Connection con = null;
		PreparedStatement ps = null;

		// Check the parameter
		if (name == null || name.trim().length() == 0) {
			throw new DAOParameterException(
					"Parameter student name is invalid or null");
		}

		try {
			con = factory.createConnection();

			ps = con
					.prepareStatement("INSERT INTO student (student_name) VALUES (?)");
			ps.setString(1, name);

			ps.executeUpdate();
		} catch (SQLException sqle) {
			throw new DAOException(sqle.getMessage(), sqle);
		} finally {
			DAOUtil.closeResources(null, ps, null, con);
		}
	}
}